Thursday, August 29, 2013

Atrial Coronary Arteries: Anatomy And Atrial Perfusion Territories

Citation: V. Subbarao Boppana, Adam Castaño, Uma Mahesh R Avula, Masatoshi Yamazaki, Jérôme Kalifa

Metformin is an oral antidiabetic drug used for treatment of Type 2 diabetes mellitus (T2DM). It acts by decreasing gluconeogenesis in the liver and absorption of glucose from the gastrointestinal system, in addition to increasing the peripheral utilization of glucose. Metformin is excreted unchanged through the renal route. Severe side effects are noted in patients with renal and/or hepatic dysfunction. These may vary from severe lactic acidosis which can be life threatening, to cardiac arrhythmias.

Neuropsychological Decline After Catheter Ablation of Atrial Fibrillation

Citation: Schwarz, N., Schoenburg M., Gerriets, T

The article “Neuropsychological decline after cath- eter ablation of atrial fibrillation” by Schwarz et al. is the first publication that focused on cognitive side effects of elective circumferential pulmonary vein isolation (PVI). Adverse neuropsychological changes after left atrial catheter ablation, as report- ed in this paper, were found in verbal memory and the result, conjoined with ischemic brain lesions, might represent cerebral side-effects of the ablation procedure.

IntravenousCorticosteroid Use Is Associated With Reduced Early Recurrence of Atrial Fibrillation Immediately Following Radiofrequency Catheter Ablation

Citation: Nitesh A. Sood, Guru M. Krishnan, Craig. I. Coleman, PharmD; Jeffrey Kluger, Moise Anglade, Christopher A. Clyne

Background: Early recurrence of atrial fibrillation (ERAF) occurs in up to 40% of patients after radiofrequency catheter ablation for atrial fibrillation (RFCA), increasing hospital stay, need for anti-arrhythmic medications (AADs) and cardioversion, and, possibly, the risk of future AF. It has been postulated that inflammation plays a key role in developing ERAF. Short term postoperative use of corticosteroids to reduce ERAF post-RFCA has not been vigorously studied.
Methods: This was a case-control study of consecutive patients undergoing RFCA for the management of AF at a single-institution. RFCA was performed by a single operator from October 2005 through July 2009. Patients receiving intravenous corticosteroids immediately following the ablation and for 48 hours (6 doses) constituted the treatment group. Controls received no intravenous corticosteroids during their hospitalization. All other management strategies were similar between the 2 groups, including the administration of AADs post- operatively. All patients had continuous electrocardiographic monitoring throughout their hospitalization. Multivariable logistic regression analysis was used to determine the impact of intravenous corticosteroids on ERAF defined as any AF>10 minutes during hospitalization.
Results: A total of 68 patients undergoing RFCA for the management of AF were included in this analysis. The overall ERAF rate, irrespective of intravenous corticosteroid use, was 23.5%. The administration of intravenous corticosteroids (n=37; mean±SD dexamethasone mean dose 11.9±4.6 mg/day; range 4-16 mg/day) was associated with an 82% reduction in patients’ odds of ERAF (adjusted odds ratio; 0.18, 95% confidence interval [CI] 0.04 to 0.78) compared with those who did not receive corticosteroids (n=31). A dose-response effect was also observed, with a 17% reduction in ERAF odds for each dexamethasone mg-equivalent administered (adjusted odds ratio; 0.83, 95%CI 0.73 to 0.96).
Conclusions: The use of intravenous corticosteroids was associated with a dose-dependent reduction in the odds of developing ERAF after RFCA for the management of AF.

Atrial Fibrillation After Lung Transplantation: Incidence, Predictors and Long-Term Implications

Citation: Santiago Garcia, Mariana Canoniero, Srinivasan Sattiraju, Lin Y. Chen, Wayne Adkisson, Marshall Hertz, David G. Benditt

Background: Little is known about the frequency of, risk factors predisposing to, and long-term impact of post-operative atrial fibrillation (AF) after lung transplantation.

Methods: A prospectively collected registry of 167 consecutive patients who underwent single or bilateral lung transplantation at the University of Minnesota Medical Center from January 1st, 2004 to December 30th, 2008 was reviewed. Post-operative AF was confirmed by review of electrocardiograms by two cardiologists. Kaplan-Meier survival curves were constructed to determine the impact of new onset AF on long-term survival.

Results: The mean age (±SD) of the population was 55 ± 11 years and 52% were male. A total of 48 patients (28%) developed AF in the postoperative period. Predictors of postoperative AF in multivariate analysis included: age (per decade) Odds Ratio (OR): 1.61, 95% confidence interval (CI) 1.10-2.34, p=0.01, postoperative thromboembolic disease OR: 9.73 (95% CI: 2.16-43.81, p<0.01, and postoperative pericarditis OR: 3.57, (95% CI: 1.38-9.22, p < 0.01). Of the 48 patients who developed post-operative AF, 41 were discharged in sinus rhythm (SR). Survival among patients who were discharged in AF was significantly lower when compared to patients discharged in SR (HR: 0.08; 0.01-0.43, p<0.05).

Conclusions: Postoperative AF is common after lung transplant. Increased age, postoperative thromboembolic disease, and pericarditis are independent predictors of postoperative AF. Persistence of AF at the time of discharge is an identifier of decreased survival.

Metformin associated Atrial Fibrillation - A Case Report

Citation: Hemant Boolani, David Shanberg, Vineela Chikkam and Dhanunjaya Lakkireddy

Metformin is an oral antidiabetic drug used for treatment of Type 2 diabetes mellitus (T2DM). It acts by decreasing gluconeogenesis in the liver and absorption of glucose from the gastrointestinal system, in addition to increasing the peripheral utilization of glucose. Metformin is excreted unchanged through the renal route. Severe side effects are noted in patients with renal and/or hepatic dysfunction. These may vary from severe lactic acidosis which can be life threatening, to cardiac arrhythmias.

Wednesday, August 28, 2013

The Role of Atrial Fibrillation Catheter Ablation in Patients with Congestive Heart Failure: “Burning”for a Cure

Citation: Dimpi Patel, Mohammed Khan

Atrial Fibrillation (AF) and congestive heart failure (CHF) often co-exist. Catheter ablation is increasingly used to cure AF related to CHF.Clinical evidence supports the feasibil- ity of catheter ablation as a treatment option in drug refractory AF patients with CHF.Investiga- tors have reported an improvement in ejection fraction, quality of life, and functional capacity

Role of Echocardiography in Atrial Fibrillation Ablation

Citation: Andrew C. Y. To MBChB, Allan L. Klein

Radiofrequency catheter ablation is an increasingly adopted strategy for difficult-to-manage patients with atrial fibrillation. Echocardiography is the key imaging modality to assess left atrialstructure and function. In this review, the role of echocardiography in atrial fibrillation ablationbefore, during and after ablation is discussed. Currently established roles of echocardiography inpatient selection pre-ablation and peri-procedural guidance, as well as newer echocardiographic techniques including the assessment of atrial mechanics are reviewed in the context of atrial fibrillation ablation.

Renin–Angiotensin System and AtrialFibrillation:Understanding the Connection

Citation: Marcello Disertori, Silvia Quintarelli

Atrial fibrillation (AF) arises as a result of a complex interaction of triggers, perpetuators and the substrate. The recurrence of AF may be partially related to a biologic phenomenon known as remodeling, in which the electrical, mechanical, and structural properties of the atrial tissue and cardiac cells are progressively altered,creating a more favorable substrate. Atrial remodeling is in part a consequence of arrhythmia itself. Therefore,to prevent and to treat AF, much attention has been directed to upstream therapies to alter the arrhythmia substrate and to reduce atrial remodeling. The renin-angiotensin-aldosterone system (RAAS) plays a keyrole in these strategies. In this review we analyze the experimental and clinical evidence regarding the efficacy of RAAS inhibitors in AF treatment. In the primary prevention of AF, meta-analyses have shown that risk of new-onset AF in patients with congestive heart failure and left ventricular dysfunction is reduced by RAAS inhibitors, whereas in hypertensive and post–myocardial infarction patients, the results are less evident. In the secondary prevention of AF, some large, prospective, randomized, placebo-controlled studieswith angiotensin II-receptor blockers returned negative results. Unfortunately, the approach of using RAASinhibitors as antiarrhythmic drugs to prevent both new-onset and recurrent AF is in decline because negativetrial results are accumulating, with the exception of the results in patients with congestive heart failure.

Stretch and Inflammation- Their Relation to Fractionation of Electrograms in Atrial Fibrillation

Citation: Uma Srivatsa, Mary Chavez CVT, Sankar Krishnamurthy, Zhongmin Li, Hong Qiu, Nipavan Chiamvimonvat

Background: Inflammatory markers (IM) are elevated in atrial fibrillation (AF). However the relation of IM to substrate modificationinAF remains unclear.We sought to assess the relationship of IM to fractio ated atrial electrogram (FAE) in patients undergoing AF ablation.

Methods: At baseline, left atrial (LA) pressure was recorded and peripheral blood was tested for IM. FAE mapping wasperformed before and after circumferential pulmonary vein and linear ablation (CPVA-L) and followed by FAEablation. Image processing was used to define the FAE areas. AF cycle-length (AFCL) was compared between baseline and after ablations from left atrial electrode.

Results: Older patients had higher cytokine levels. FAE area at baseline (secondary FAE) negatively correlated with the levels of interleukin-6 (IL-6, R2= -0.97 and p=0.03) and interleukin-12p70 (IL-12p70, R2= -0.97 and p=0.03). In addition, a significant reduction in FAE area and index occurred after CPVA-L (p=0.0001). FAE after CPVA-L (primary FAE) correlated with left atrial pressure (LAP), [R2 0.5, (p=0.02)]. The AFCL (in msec) increased from 135 ± 41 to 149.5+30 (p=ns) after CPVA-L and further increased to 191.5 ± 60 (p=0.007) after FAE ablation.

Conclusions: There is a negative correlation of IL-6 and IL-12p70 to baseline FAE, suggesting a possibility of sequestration of these cytokines in left atrium. CPVA-L ablation reduces FAE area which when ablated increases AFCL, suggesting that these areas likely represent primary fragmentation due to rotors, triggered by atrial stretch as seen by the relation of left atrial pressure and post CPVA-L FAE.

Risk Alteration for Atrial Fibrillation with DifferentAntihypertensive Drugs

Citation: Vivencio Barrios, Carlos Escobar

A large percentage of patients with hypertension suffer from atrial fibrillation (AF). The concomitance of both conditions in the same patient markedly increases cardiovascular risk. Therefore, prevention of new-onset AF in hypertensive population should be a relevant target.

High blood pressure promotes structural and electrophysiological changes in the heart that promote the develop- ment of AF. Thus, the most important therapeutic approach to prevent incident AF in hypertensive population is to reduce blood pressure values to recommended goals. However, in specific conditions, some antihypertensive agents may provide additional benefits beyond blood pressure reduction, such as in hypertension with left ven- tricular hypertrophy with renin angiotensin system blockade. On the other hand, in patients with hypertension and permanent AF, beta blockers and nondihydropiridine calcium antagonists (verapamil and diltiazem) play an important role.

Antihypertensive agents may provide beneficial effects on incident AF, regardless of the presence of hyperten- sion. Thus, renin angiotensin system inhibitors may reduce new-onset AF in patients with heart failure or after the cardioversion of persistent AF. On the other hand, the preoperative administration of beta blockers may re- duce the incidence of postoperative AF in some patients.

In this manuscript, the available evidence about the effects of different antihypertensive agents on new-onset AF in different populations is reviewed.

Atrium-Atrioventricular Node Conduction Block during Catheter Ablation of Persistent Atrial Fibrillation

Citation : Yoshihide Takahashi

Previous studies have suggested that fibrillatory substrates are widely distributed in both atria in patients with persistent atrial fibrillation. Extensive bi-atrial ablation has been increasingly performed to improve the clinical outcomes; however, this may adversely affect the intra-atrial conduction during sinus rhythm. The worst con- sequence of an intra-atrial conduction disturbance is conduction block between the atrium and atrioventricular node. There have been a few case reports on this complication, which suggest that the conduction block may occur more. This review aimed to describe the risk factors and method of prevention of atrium-atrioventric-ular node conduction block.

Prevention of Stroke in Patients With Atrial Fibrillation

Citation : Talal Moukabary, Gerald V. Naccarelli

The presence of atrial fibrillation (AF) increases the risk of stroke, especially in patients with risk factors as outlined by the CHADS2 and CHA2DS2-VASc scoring systems. Although warfarin can reduce stroke rates by over 65%, only 55% of patients, in the USA, who should be on warfarin for AF and stroke prevention are taking the drug due to the need of INR monitoring, difficulties in maintaining a therapeutic INR in the therapeutic range and dietary and drug interactions. Dabigatran, an oral direct thrombin inhibitor and rivaroxaban and apixaban, factor Xa inhibitors, have demonstrated efficacy in reducing stroke in large clinical trials. These novel anticoagulants will change the therapeutic landscape since patients will be able to prevent stroke with a lower risk of intracranial hemorrhage and without the need for INR monitoring and less drug-dietary interactions.

Catheter Ablation of Atrial Fibrillation in Overweight and Obese Patients

Citation : Louiza Lioni, Panagiotis Korantzopoulos, Konstantinos P. Letsas

Obesity has reached epidemic proportions, and is associated with increased all-cause mortality. Atrial fibrillation(AF), the most common sustained arrhythmia in the clinical practice, is associated with an increased longterm risk of stroke, heart failure, and all-cause mortality. Accumulating data points out to an indispensable role of inflammation in both obesity and AF. Recent studies have documented an increasing risk of AF with increasing body mass index (BMI). The pathophysiological alterations associated with overweight and obesity lead to atrial stretch and atrial enlargement creating the substrate for AF development. Catheter ablation of AF has been widely accepted as an important therapeutic modality for the treatment of patients with symptomatic,drug-refractory AF. Previous studies assessing the impact of BMI on AF catheter ablation outcomes have given conflicting data. Given that overweight and obesity, as defined by BMI, and AF are closely linked,the present review sought to investigate the impact of BMI on the efficacy and safety of AF catheter ablation.

The Concept of “Burden” in Atrial Fibrillation

Citation : Gregg F. Rosner, James A. Reiffel, Kathleen Hickey

Over the last decade or so the term “burden” has become frequently encountered in manuscripts discussing atrial fibrillation (AF). AF “burden” is perhaps most commonly encountered in the electrophysiological context – the amount of time the patient is in AF out of the total monitored time (i.e., the percent of time one is in AF). However, “burden” in AF may also be used in other contexts, which we characterize below as “disease burden”, “clinical burden,” “economic burden.” Over the course of the disease progression and its therapy, such “burdens” may change, and may do so in parallel with each other or in opposite directions. This manuscript explores these various concepts of AF “burden” so as to emphasize to authors and readers that when using the term, its meaning must be made clear.

A Novel Transgenic Mouse Model of Cardiac Hypertrophy and Atrial Fibrillation

Citation : Michael A. Rosenberg, Saumya Das, Pablo Quintero Pinzon, Ashley C. Knight, David E. Sosnovik, Patrick T. Ellinor, Anthony Rosenzweig

Cardiac hypertrophy is a major risk factor for the development of atrial fibrillation (AF). However, there are few animal models of AF associated with cardiac hypertrophy. In this study, we describe the in vivo electrophysiological characteristics and histopathology of a mouse model of cardiac hypertrophy that develops AF. Myostatin is a well-known negative regulator of skeletal muscle growth that was recently found to additionally regulate cardiac muscle growth. Using cardiac-specific expression of the inhibitory myostatin pro-peptide, we generated transgenic (TG) mice with dominant-negative regulation of MSTN (DN-MSTN). One line (DN-MSTN TG13) displayed ventricular hypertrophy, as well as spontaneous AF on the surface electrocardiogram (ECG), and was further evaluated. DN-MSTN TG13 had normal systolic function, but displayed atrial enlargement on cardiac MRI, as well as atrial fibrosis histologically. Baseline ECG revealed an increased P wave duration and QRS interval compared with wild-type littermate (WT) mice. Seven of 19 DN-MSTN TG13 mice had spontaneous or inducible AF, while none of the WT mice had atrial arrhythmias (p<0.05). Connexin40 (Cx40) was decreased in DN-MSTN TG13 mice, even in the absence of AF or significant atrial fibrosis, raising the possibility that MSTN signaling may play a role in Cx40 down-regulation and the development of AF in this mouse model. In conclusion, DN-MSTN TG13 mice represent a novel model of AF, in which molecular changes including an initial loss of Cx40 are noted prior to fibrosis and the development of atrial arrhythmias.

Monday, August 26, 2013

South Asians are Under-Represented in a Clinic Treating Atrial Fibrillation in a Multicultural City in the UK

Citation : MH Tayebjee, K Tyndall, S Holding, C Russell, LN Graham, CB Pepper

The Leeds rapid access atrial fibrillation (AF) clinic was set up to streamline and standardise management of patients with newly diagnosed AF. Anecdotal evidence suggests that there is under-representation of south Asians in these clinics. All patient attendances between June 2007 and June 2011 were documented and combined with ethnicity data from patient administration records. Local population demographics for 2009 were obtained from the office of national statistics. This was used to estimate the expected prevalence of AF across the different ethnic groups in Leeds taking age into account. One thousand two hundred and ten patients were referred. The study sample included 992 patients, and the number of south Asians attending was 88% less than expected (Chi squared analysis; p<0.0001). These results suggest that there is an under-representation of south Asians in a large centre that serves a cosmopolitan population. Potential reasons for this discrepancy including barriers to accessing treatment for this population or a lower prevalence of AF in south Asians due to an as yet unidentified genetic factor.

Role of Echocardiography in the Management and Prognosis of Atrial Fibrillation

Citation : David I Silverman, Srilatha R. Ayirala, Warren J Manning

Echocardiography plays a longstanding and vital role in the management of atrial fibrillation (AF). Advances in 2D imaging, Doppler echocardiography and strain imaging have all contributed to major progress in AF treatment. Echocardiographically measured left atrial (LA) volume is a powerful predictor of maintenance of sinus rhythm following cardioversion as well as risk of thrombus formation and thromboembolism. Doppler derived parameters of atrial mechanical function including atrial ejection force provide related prognostic information. Transesophageal echocardiocardiograpy (TEE) guided cardioversion of AF allows for rapid conversion to sinus rhythm without prolonged oral anticoagulation, and TEE serves as a useful tool during catheter ablation of AF and atrial flutter. Newer measures derived from speckle tracking offer great promise in further improving the care of patients with AF.

Left Atrial Diastolic Dysfunction following Catheter Ablation of Atrial Fibrillation

Citation : Hsin-Yueh Liang, Ruey J. Sung

Radiofrequency catheter ablation (RFCA)-induced thermal injury may cause and/or worsen left atrial (LA) diastolic dysfunction leading to pulmonary hypertension and heart failure in patients with atrial fibrillation (AF), the incidence of which is probably more common than is generally realized. Biplane 2-dimensional echocardiography coupled with tissue Doppler (velocity) imaging and Doppler-derived strain (rate) imaging can be applied to provide quantitative assessment of the LA function (both systolic and diastolic) relative to pulmonary venous circulation and left ventricular function. Information so obtained is useful for guiding follow-up management of patients undergoing RFCA of AF.

Necessity of Repeat Ablations to Eliminate Atrial Fibrillation

Citation : Stephanie Fichtner, Gabriele Hessling, Isabel Deisenhofer

Atrial fibrillation (AF) is the most common human arrhythmia and leads to increased morbidity and mortality. Because of demographic changes, the prevalence of AF will increase in the next decades, requiring better primary prevention strategies and better treatment options. In 1998, Haissaguerre et al. described triggering foci in the pulmonary veins (PV) as the prevailing pathophysiological initiator of paroxysmal AF. Since then, multiple studies have been conducted using the technique of pulmonary vein isolation (PVI) to eliminate AF. In short term follow-up, success rates of 60-75% in patients with paroxysmal AF are reached, with significantly worse results in persistent AF of approximately 50%. Due to arrhythmia recurrence, multiple procedures are often necessary, especially in patients with persistent AF, to achieve these results. It is supposed that the cause of arrhythmia recurrence is pulmonary vein reconnection in patients with paroxysmal AF, and insufficient substrate modification or new substrate development in patients with persistent AF. Future techniques like contact force control might improve lesion formation leading to improved PVI and substrate modification.

Adverse Outcomes from Atrial Fibrillation; Mechanisms, Risks, and Insights Learned from Therapeutic Options

Citation : David L. Johnson, PA-C, John D. Day, Srijoy Mahapatra, T. Jared Bunch

Atrial Fibrillation (AF) continues to increase in prevalence and its’ consequences and disease associations have a great impact on multiple aspects of medical practice. As such, making preventive strategies to minimize risk of the arrhythmia and its’ complications are paramount to improve quality of life, mortality, and limit medical resource utilization. To the extent that AF independently impacts adverse cardiovascular outcomes, this review article will focus on these outcomes, in particular heart failure (HF), stroke, and mortality, and discuss contemporary strategies for treatment.

Conclusions: AF has a marked deleterious impact on the lives of patients. This impact can be accelerated when other cardiac diseases coexist. Although rhythm control strategies have been an intriguing tool to reverse or minimize the adverse outcomes associate with AF, they have largely been unsuccessful. In general, failures of currently available AADs to improve survival are due to failure of the drug to maintain sinus rhythm and presence of drug toxicities. Early data with ablation approaches are favorable and support rhythm control strategies to minimize long-term risks associated with AF. However, most of the data stem from observational analysis or small randomized trials. Large randomized prospective trials will ultimately define the role of catheter ablation in the management of AF patients.

Friday, August 23, 2013

Collateral Damage During Ablation of Atrial Fibrillation – Lessons Learnt in the Past Decade

Citation : David Spragg

Atrial fibrillation (AF) is a common tachyarrhythmia. There are over 2 million patients in the US with AF currently,1 and as the median age of the population increases, the prevalence of AF likely will as well. Strategies for treating AF are diverse, and include options ranging from simple observation to pharmacotherapy to catheter-based and surgical interventions. Therapeutic approaches to AF historically have been divided into rate-control and rhythm-control categories, the former focusing on simply reducing ventricular response rates and the latter on restoration of sinus rhythm.Over the last 15 years, there has been an explosion of rhythm-control therapies, particularly in the field of catheter-based ablation. The proliferation of these ablative approaches has led to new insights into AF, both in terms of the mechanism(s) of the disease itself, and in the potential harm that patients can suffer during attempts at restoration of sinus rhythm. This review focuses on the complications, both the familiar and the newly appreciated, that may occur during catheter ablation of AF.

Age as a Risk factor for Atrial Fibrillation and Flutter after Coronary Artery Bypass Grafting

Citation : Prashant Bhave, Rod Passman

Atrial fibrillation affects approximately 3 million people in the United States and creates a huge burden on the health care system, both in terms of morbidity, mortality, and cost. The prevalence of atrial fibrillation rises sharply with increases in age. It is estimated that 8% of people above 70 years of age have atrial fibrillation. Atrial fibrillation has long been recognized as a powerful risk factor for stroke, heart failure, and mortality. Advancing age amplifies the risk of all of these sequelae of atrial fibrillation.

Phrenic Nerve and Esophageal Injury During Catheter Ablation of Atrial Fibrillation

Citation : Shinsuke Miyazaki, Yoshito Iesaka

Atrial fibrillation is a common cardiac arrhythmia with rapid and irregular atrial activity. Although radiofrequency catheter ablation of atrial fibrillation has became an established treatment for the management of symptomatic drug refractory patients in the past decade, several complications due to the procedure have been reported. The purpose of this review article is to describe the collateral damage from catheter ablation of atrial fibrillation.

Predictors of Recurrence After Catheter Ablation of Persistent Atrial Fibrillation

Citation : Thomas Deneke, Anja Schade, Joachim Krug, Karsten Stahl, Geza-Atilla Szollosi, Dong-In Shin, Clemens Nino Schukro, Mohamed El Tarahony, Enrique Murillo, Semko Aram, Gabriele Robhirt, Thomas Lawo, Andreas Mugge, Peter H. Grewe, Sebastian Kerber

Catheter ablation of atrial fibrillation (AF) has been increasingly used to treat symptomatic patients. Within the last years a growing interest in ablation of persistent AF forms has evolved. Factors that may influence outcome of these procedures to treat persistent AF may be patient-specific (pre-procedural), procedure-related or may involve different post-ablation follow-up strategies. In this review potential factors predicting recurrence of AF after ablation of persistent AF have been evaluated. In essence, data is limited mostly due to incongruent definitions of persistent AF. Left atrial dimensions, duration of continuous AF and AF cycle length may be patient-specific predictors of outcome. Intra-procedural parameters involved in recurrence prediction may be extent of ablation (effective pulmonary vein isolation appears mandatory) and termination of AF during ablation. Timing and number of cardioversion if persistent AF recurs may predict outcome, as well.

Many studies have identified strators for higher recurrence rates in rather small patient groups and need to be further evaluated in larger patient collectives.

Conversion of Persistent Atrial Fibrillation After Radiofrequency Ablation by Ibutilide

Citation : Pipin Kojodjojo

Ablation of peristent AF remains challenging with questions unanswered about what the ideal next step after pulmonary venous isolation should be. Ibutilide is a highly effective class III agent for cardioversion of acute-onset atrial flutter and fibrillation, with limited clinical use due to risks of ventricular pro-arrhythmias. However, results from the on-going MAGIC-AF trial may re-invigorate its role in clinical electrophysiology as an invaluable adjunct to facilitate controlled substrate modification during ablation of persistent AF.

Thursday, August 22, 2013

Preventative Measures of Stroke in Patients With Atrial Fibrillation

Citation : Ahmed Adlan , Gregory YH Lip

Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia and is associated with increased morbidity and mortality due to stroke and thrombo-embolism. In patients with AF, strokes are usually more severe, resulting in longer hospital stays, worse disability and considerable healthcare costs. The prevention of stroke therefore is crucial in the management of AF. Stroke risk stratification tools can be used to determine patients at higher risk of stroke, and if no contraindications are present oral anticoagulation (OAC) therapy can be initiated. Despite the strong evidence for the benefit of OAC in stroke prevention in patients with AF, the use of thromboprophylaxis remains inadequate. The key measures to prevent stroke in patients with AF include: adequate stroke risk assessment and thrombo-prophylaxis; prompt initiation of OAC and avoidance of interruptions; earlier detection of AF; and education to overcome the under-usage of OAC in elderly patients.

norOutcome of Patients Discharged after their First Detected Episode of Atrial Fibrillation

Citation : Sophie Gomes, Laure Champ-Rigot, Anthony Foucault, Arnaud Pellissier, Alain Lebon, Patrice Scanu, Paul Milliez

Atrial fibrillation (AF) is the most frequent supraventricular arrhythmia with an approximative prevalence of 1 % in the general population and above 6 % in the elderly. After a first AF diagnosis, the hospitalization rate is markedly increased. Management of a first AF episode is different depending on the clinical status of patients. Practical guidelines developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society are available for the management of these patients. A four-step decisional scheme must be followed in the management of a first recent AF episode: need for a short- and long-term anticoagulation, define a rythmologic strategy (rhythm or rate control), select the weapon (drug, device or ablation) and reconsider the strategy if needed. After a first uncomplicated paroxysmal AF episode, guidelines recommend that prescription of antiarrhythmics must be avoided and anticoagulation is optional. After a first persistent AF episode, guidelines recommend to either respect or reduce the arrhythmia. Prescription of antiarrhythmics and anticoagulation is also optional depending on the patient’s condition. In case of the AF reduction decision, anticoagulation must be tailored preliminary to this reduction. AF recurrence rate varies depending on the patient’s condition, and the risk of stroke assessed by the CHA2DS2-VASc score might be similarly considered for both paroxysmal and persistent AF.

Risk of Arrhythmia Recurrence After Successful Ablation of Lone Atrial Fibrillation

Citation : Khaykin Y, Friedlander D, Zarnett L, Seabrook C, Beardsall M, RN, Feltham S, RN, Tsang B, Wulffhart Z, Pantano A,  Verma A

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is difficult to treat. It may present with a variety of symptoms ranging in severity from mild to disabling. While some patients get diagnosed at the time of a routine visit and are not aware of their arrhythmia, others may present with palpitations, chest discomfort, dyspnea and syncope. Atrial fibrillation is commonly associated with cardiac and extra cardiac conditions such as valve disease, left ventricular dysfunction, hypertension, diabetes, pulmonary and thyroid disease.

Cardiac Resynchronization Therapy in Patients with Atrial Fibrillation - Worth the Effort?

Citation : António M Ferreira, MD; Pedro Carmo, MD; Pedro Adragão

Congestive heart failure (CHF) and atrial fibrillation (AF) are two increasingly common conditions that predispose to each other and frequently coexist. Cardiac resynchronization therapy (CRT) has emerged as an important therapeutic modality for selected patients with end-stage CHF. However, despite the high prevalence of AF in patients eligible for CRT, almost all the randomized clinical trials that validated the benefit of resynchronization therapy excluded patients with preexisting AF. In this review, we examine the available evidence on the benefits and limitations of CRT in patients with AF and discuss recent data that narrowed the knowledge gap on this topic.

Enhancing Cardiac Resynchronization Therapy for Patients with Atrial Fibrillation: The Role of AV Node Ablation

Citation : Jeff M. Berry, Jose A. Joglar

Cardiac resynchronization therapy (CRT) has evolved as an effective therapy for patients with congestive heart failure (CHF) and ventricular dyssynchrony, currently defined as a wide QRS on the electrocardiogram. While multiple randomized controlled trials have confirmed the favorable effects of CRT on mortality and heart failure symptoms for patients in sinus rhythm, only recently observational studies have begun to suggest a similar benefit for patients with atrial fibrillation (AF) and dyssynchrony. Yet, implementing effective biventricular pacing in patients with AF can be problematic due to competing intrinsic AV conduction. For patients with depressed ejection fractions needing AV node (AVN) ablation to control fast ventricular rates, biventricular pacing has been shown to be superior to right ventricular pacing alone. When consistent pacing (over 90% of the time) cannot be achieved in AF patients due to a rapid ventricular response despite pharmacological therapy, AVN ablation should be considered. The additional benefit of performing AVN ablation to promote biventricular pacing in patients without rapid ventricular rates remains uncertain. A randomized controlled trial is needed to test the incremental benefit of AVN ablation to promote biventricular pacing in heart failure patients with AF and wide QRS.

Wednesday, August 21, 2013

Atrial Fibrillation and Oral Anticoagulation in Chronic Kidney Disease

Citation : Christiane Engelbertz, Holger Reinecke

Due to several unfavorable epidemiological changes, chronic kidney disease (CKD) and treatment of its associated cardiovascular morbidity have become a worldwide problem. Thus, atrial fibrillation (AF) is the most common arrhythmia and frequently associated with renal impairment: prevalence for AF is up to 27% in long-term hemodialysis patients and in general more than 25% in all CKD patients 70 years and older. Thromboembolism and stroke are the major complications of AF. Two-year death rates for CKD patients after stroke range between 55% and 74%. Although treatment of AF in the general population is well defined, patients with CKD and AF are often undertreated due to lack of studies and guidelines. In this review recent data concerning incidence and prevalence of AF, stroke, and major bleedings in CKD patients are presented. Particular attention is paid to the available data about the different types of oral anticoagulation therapy with regard to CKD stage, including the new oral anticoagulant drugs dabigatran, rivaroxaban, and apixaban. Stratification algorithms for stroke risk in general, and individualized risk stratification for oral anticoagulation in CKD patients are discussed in detail.

Risks from Catheter Ablation of Atrial Fibrillation: A Review of Methods, Efficacy, and Safety

Citation : Richard Cheng, Melisa Chang, Chee Yuan Ng

Atrial fibrillation (AF) is the most common arrhythmia and is a significant burden to healthcare cost. AF causes congestive heart failure, thromboembolic events such as stroke and intolerable symptoms in some patients. With the advances and increasing experience in catheter ablation, there is now an established role for catheter ablation in patients with atrial fibrillation. The risks, complications and patient features associated with it are increasingly recognized. A recent worldwide survey has shown an increasing number of medical centers that are practicing catheter ablation of atrial fibrillation, predominantly with pulmonary vein isolation techniques. However, catheter ablation is an invasive therapy in AF and is associated with a few major complications. Patient selection, ablation technique, and catheter energy source all influence the efficacy and safety of the procedure. Finally, while several randomized control trials have compared the efficacy of catheter ablation versus antiarrhythmic drug therapy, a number of trials are on the horizon to explore its role as a first line therapy for atrial fibrillation. New energy catheter energy sources are also being explored.

Epicardial Fat and Atrial Fibrillation: A Review

Citation : M. Obadah Al Chekakie, Joseph G Akar

Atrial fibrillation (AF) is a progressive disorder that increases with age. Obesity is an important risk factor for AF. Pericardial fat is an active adipose tissue in close proximity to the heart and has been shown to be a risk factor for structural as well as coronary artery disease independent of body mass index. Recent studies suggest a role of epicardial fat in atrial remodeling as well as AF burden. This review will summarize the recent evidence linking epicardial fat and AF.

Treating Atrial Fibrillation With Cryoballoon Technology

Citation : David R. Altmann, Sven Knecht, Christian Sticherling, Peter Ammann, Beat Schaer, Stefan Osswald, Michael Kühne

Cryoballoon ablation has emerged as a novel tool to perform pulmonary vein isolation. The aim of this paper is to review the advantages, drawbacks as well as possible complications and clinical outcomes of this technology and to discuss some important technical issues.

reAltered Excitation-Contraction Coupling in Human Chronic Atrial Fibrillation

Citation : Eleonora Grandi, Antony J. Workman, Sandeep V. Pandit

This review focuses on the (mal)adaptive processes in atrial excitation-contraction coupling occurring in patients with chronic atrial fibrillation. Cellular remodeling includes shortening of the atrial action potential duration and effective refractory period, depressed intracellular Ca2+ transient, and reduced myocyte contractility. Here we summarize the current knowledge of the ionic bases underlying these changes. Understanding the molecular mechanisms of excitation-contraction-coupling remodeling in the fibrillating human atria is important to identify new potential targets for AF therapy.

Temporal and Spatial Indices of AF Regularization Predict Intraprocedural AF Termination and Outcome

Citation : Tina Baykaner, David E Krummen, Sanjiv M. Narayan

Ablation has become a cornerstone of therapy for atrial fibrillation (AF), the most common arrhythmia in the Western world and an important cause of morbidity and mortality. However, the optimal approach for ablation remains hotly debated, and this is particularly true for the selection of procedural endpoints. Since seminal studies by Haïssaguerre et al. showed that ectopy from the pulmonary veins (PVs) may trigger paroxysms of AF, PV isolation has become central to most ablation approaches. However, PV isolation often fails to terminate AF, particularly in patients with persistent AF, indicating AF sustaining mechanisms that lie outside the PVs. For this reason or to eliminate additional triggers, many approaches to ablate extra-PV tissue have been devised whose AF termination rates range from 58%  to 87%. However, some constants remain. First, the event of AF termination is currently extremely difficult if not impossible to predict a priori. Second, AF termination by current ablative approaches is typically to atrial tachycardia, rather than to the sinus rhythm from which AF usually initiates. Finally, third, despite the intuitive advantages of AF termination, it remains disputed whether AF termination by current approaches is a desirable endpoint that improves long-term outcome. This brief review focuses on these facets of intra-procedural AF termination.

Risk Factors for the Development of Atrial Fibrillation in HIV Infected Patients

Citation : Yaser Elnahar, Joseph Daoko, Anthony Al-Dehneh, Nishant Gupta, Vincent A. DeBari, Fayez Shamoon, Constantinos A. Costeas

Background : Patients with Human Immunodeficiency Virus (HIV) have an array of multi-organ involvement, including cardiovascular disease. CD4 count is one of the best parameters to monitor the severity of HIV disease. The arrythmogenic potential of HIV disease has not been well defined. The aim of the study is to establish whether an association between the severity of HIV and atrial fibrillation (AF) exists.

Methods : Out of a retrospective cohort of 780 HIV patients from January 2006 to December 2008, 40 patients were selected that developed AF during this period .The age and sex matched controls (n=40) were selected for comparison. The comparison between both groups was done using Fischer Exact Test. Bivariate and multivariate analysis was also performed to analyze the results. 

Results : The data shows that 47%(19/40) of the patients with HIV who developed AF had CD4 count lower than 250 as compared to 20%(8/40) in the control group (P value = 0.017)

Conclusions : The data supports the presence of a relationship between HIV and AF. Patients with lower CD4 counts are more susceptible to develop AF.

Demographic Characteristics and Patterns of Medication in Atrial Fibrillation Patients in South West Ontario: Insights from a Large Primary Care Database

Citation : Robert J Petrella, Luc Sauriol

Background : Information about current practice in primary care-based management of atrial fibrillation (AF) can help to improve care quality.

Purpose : To assess the epidemiology of AF and current patterns of treatment in order to identify therapeutic trends and aspects of current practice that may allow for care-gap identification.

Methods : We scrutinized the anonymized records of the South Western Ontario database (SWO) collected between July 2002 and October 2008 for information about the characteristics and management of AF patients.

Results : From a population of ~168,000 patients we identified 4922 patients with a diagnosis of AF (2.9%). The recorded prevalence of AF increased with age, from <2% at age <60 years to 6% in the age range 71–75 years and 10% at age ≥81 years. AF patients were characterized by an unfavourable cardiovascular risk profile including widespread hypertension (54% of all cases), coronary artery disease (37%) and heart failure (21%), many cases of which were advanced (New York Heart Association class III or IV). Diabetes (22%) and dyslipidaemia (31%) were also widely prevalent.
The most frequently prescribed anti-arrhythmic drugs (AADs) were sotolol (n=798), amiodarone (n=712) and propafenone (n=451). Recorded use of flecainide was relatively low (n=175). Rate control-agents were being prescribed for 1838 patients, beta-blockers for 1311 patients and calcium channel blockers (CCBs) for 784 patients.
Use of anticoagulants was higher among patients assigned to AADs than among those assigned to rate-control drugs (≥25% vs. ~10%). Overall prescription rates for other concomitant medications were >50% for ACE inhibitors/ARBs, 30–35% for statins and beta-blockers, and 27–29% for diuretics, digoxin and CCBs.

Conclusions : These Canadian patients with AF were relatively elderly and had multiple concomitant cardiovascular conditions and medications.

Impact of Chronic Anemia on the New-Onset Atrial Fibrillation in the Elderly: It May Not Be What We Have Thought

Citation : Harsha V. Ganga, Nandini Kolla, M. Bridget Zimmerman, Wayne L. Miller

Objective : To determine if a clinically significant relation exists between chronic anemia and the new-onset atrial fibrillation (AF) in the elderly population from a community setting.

Patients and Methods : This is a single center community-based retrospective cohort study. Data were collected on 3867 patients over the age of 65 years presenting to the Mercy Medical Center in the year 2006. Patients without AF were divided into anemic and non-anemic groups and were followed over the next two years for the new-onset AF. Chronic anemia was defined as hemoglobin level less than 13g/dl in males and less than 12g/dl in females from two laboratory values checked at least 4 months apart.
Results : Of the 2873 patients without AF, 2382 (83%) patients were non-anemic. 491 patients were anemic. New-onset AF was found in 7.5 % of the anemic patients and 5.5% of the non-anemic patients. After the adjustment for comorbid conditions, chronic anemia is not associated with new-onset AF (p=0.922).
Conclusion : In this study cohort of elderly community-based patients, chronic anemia is not associated with the new-onset AF.

angiogNon- interventional Management of Symptomatic Pulmonary Vein Occlusion after Radiofrequency Ablation for Atrial Fibrillation

Citation : Logan Bittinger, Anthony Tang

Pulmonary vein occlusion (PVO) after atrial fibrillation ablation is often highly symptomatic. In cases with a clear target, balloon angioplasty and stenting can be successful. In the absence of such a target, surgical lobectomy has been reported as a treatment option, but the natural history of physiological adaptation may outweigh the risks of invasive therapies and a non-invasive strategy is valid in these situations. We present a case of highly symptomatic PVO managed non-invasively, with complete symptom resolution and return to high-intensity exercise. Catheter intervention may not always be possible in the absence of a target vessel, and lobectomy may not be necessary to manage PVO.

Thursday, August 15, 2013

Relationship Between Arrhythmia and Sleep Disordered Breathing

Citation : Ahmad Hersi

The association between obstructive sleep apnea (OSA) and cardiovascular disease is well known. Data from most studies investigating the prevalence of OSA in atrial fibrillation (AF), and of AF in patients with OSA, have supported the relationship between these common diseases. In addition, several studies have shown a detrimental effect of OSA on AF treatment. These reports vary considerably in methodology, and are particularly diverse in their definitions and diagnosis of OSA and patient populations studied. Considering these studies individually while exploring their methodological variations and the range of results achieved can reinforce the necessity of establishing standards for performing this important research. Reviewing these studies should en courage practitioners to reflect on how the methodologies, patients, and outcomes are relevant to their practices.

Association Between BMI and QoL Improvement in AF Patients Following Catheter Ablation

Citation : Martin Martinek, Helmut Purerfellner

As quite a lot of data has been recently reported on the impact of body mass index (BMI) on (1.) the risk of atrial fibrillation (AF) development, (2.) peri-procedural risk in pulmonary vein isolation (PVI) and (3.) PVI outcome, as well as (4.) quality of life (QoL) after PVI, we would like to dedicate our review to these topics. We will try to give a general picture about the impact of obesity on AF and end our review commenting on new data specifically highlighting the association between BMI and QoL improvement in AF patients following catheter ablation.

Tuesday, August 13, 2013

The Estimated Risk of Atrial Fibrillation Related to Alcohol Consumption

Citation : Michael A. Rosenberg, Kenneth J. Mukamal

The risk of acute heavy alcohol intake on the development of atrial fibrillation (AF), aka ‘holiday heart syndrome’, has been well-described. However, whether chronic alcohol intake is also associated with increased risk of AF, or might even be protective as has been observed with other cardiac conditions, is more uncertain. A number of studies, from basic science to large cohort studies have been performed to analyze the association between alcohol and AF. Basic-level studies have found that alcohol causes changes in tissue electrophysiology, ion channels, and circulating hormones, which might promote development and maintenance of AF. Clinical studies have generally shown groups with the highest regular intake of alcohol to be at increased risk, with no association with more moderate use. However, these studies have not always accounted for other AF risk factors, been inconsistent in the assessment and validation of the quantity of alcohol consumed across populations, and been unable to completely separate drinking patterns from overall health of participants. As a result, solid conclusions about a threshold level for ‘safe’ chronic alcohol intake cannot be made with regard to AF risk, but it appears to be safe within currently recommended limits of 1 drink daily for women and 2 for men. In this review, we discuss these findings, limitations, and conclusions.

The Relationship Between Atrial Fibrillation and Chronic Kidney Disease : Epidemiologic and Pathophysiologic Considerations for a Dual Epidemic

Citation : David D. McManus, Jane S. Saczynski, Jeanine A. Ward, Khushleen Jaggi, Peter Bourrell, Chad Darling, Robert J. Goldberg

Atrial fibrillation (AF) presently affects over 2 million Americans, and the magnitude and population burden from AF continues to increase concomitant with the aging of the U.S. population. Chronic kidney disease (CKD) is present in 13% of individuals in the U.S., and the prevalence of CKD is also rapidly increasing. The increasing population burden of CKD and AF will profoundly affect the clinical and public health, since CKD and AF are both associated with lower quality of life, increased hospitalization rates, and a greater risk of heart failure, stroke, and total mortality. AF and CKD often co-exist, each condition predisposes to the other, and the co-occurrence of these disorders worsens prognosis relative to either disease alone. The shared epidemiology of CKD and AF may be explained by the strong pathophysiologic connections between these diseases. In order to promote a better understanding of CKD and AF, we have reviewed their shared epidemiology and pathophysiology and described the natural history of patients affected by both diseases.

Chronic Kidney Disease and Atrial Fibrillation: A Contemporary Overview

Citation : Nitin Kulkarni, Nilusha Gukathasan, Samantha Sartori, Usman Baber

Chronic kidney disease (CKD) is associated with substantial cardiovascular morbidity, including myocardial infarction, heart failure and stroke. Similar to CKD, atrial fibrillation (AF) is a prevalent arrhythmia that increases risk for both stroke and overall mortality. Recent studies demonstrate that both prevalence and incidence of AF is higher in patient with versus without renal impairment and risk for developing AF increases as renal function worsens. Potential mechanisms for the higher burden of AF in CKD patients include but are not limited to augmented sympathetic tone, activation of the renin-angiotensin-aldosterone system and myocardial remodeling. Similar to the general population, AF confers an increased risk for both stroke and overall mortality in the CKD population. The safety and efficacy of antithrombotic therapy across the spectrum of CKD remains unknown, however, as patients with advanced renal failure are frequently excluded from randomized trials. While treatment with vitamin K antagonists appears to reduce ischemic complications without significant bleeding harm in patients with mild to moderate CKD and AF, the risk benefit ratio of anticoagulation among thosewith advanced renal failure on dialysis requires further investigation. Prospective, randomized trials are war ranted to define the impact of antithrombotic therapy on reducing stroke risk in patients with both AF and CKD.

Atrial Fibrillation Associated with Heart Failure, Stroke and Mortality

Citation : Stefano Bordignon, Maria Chiara Corti, Claudio Bilato

Atrial Fibrillation (AF) is the most common arrhythmia in the western world. Because AF prevalence rises with age and western populations are increasingly aging, AF has been called a “growing epidemic”, especially among older persons, with social and economic consequences. AF may concur to disability and may cluster with other co-existing clinical conditions. AF is an independent risk factor for stroke by increasing the thromboembolic risk profile and is associated with heart failure severity. Among persons with AF, prevalence of stroke, coronary heart disease, peripheral artery disease, cognitive impairment and physical disability is significantly higher. AF is associated with higher risk of mortality through the association with stroke and heart failure: ischemic strokes are more severe if AF is present and AF may represent a marker of more severe heart failure. Independently of other known predictors of mortality, death rates are almost doubled by AF. AF, therefore, is a considerable source of morbidity and mortality, is associated with disability, and is a major determinant of quality of life.

Cost-Effective Medicines for Stroke Prophylaxis in Patients with Atrial Fibrillation

Citation : Anjan K. Chakrabarti, Shalin J. Patel, Payal Kohli, Jacob A. Udell, Priyamvada Singh Lakshmi Gopalakrishnan, Varun Kumar, C. Michael Gibson

Non-valvular atrial fibrillation is the most common arrhythmia encountered in clinical practice and is associated with substantial healthcare costs. The risk of thromboembolic stroke is 3-5 times higher in patients with atrial fibrillation compared with the general population. Until the recent emergence of direct thrombin (factor IIa) and factor Xa inhibitors, antithrombotic therapy for atrial fibrillation was achieved with antiplatelet agents or vitamin K antagonists, which are considered cost-effective strategies when compared to no treatment. Now newer agents, such as the direct thrombin inhibitor dabigatran, can lower thromboembolic events and reduce the risk of fatal and intracerebral hemorrhage compared with warfarin, in addition to eliminating the need for costly therapeutic monitoring. Multiple analyses have shown that dabigatran, when compared with warfarin therapy that achieves a time in therapeutic range (TTR) consistent with previous large-scale trials, is a cost-effective approach to antithrombotic therapy in atrial fibrillation, ranging from $16,385 to $86,000 per quality-adjust life-year (QALY) gained. It has been shown to be especially cost-effective (QALY < $50,000) for high stroke-risk patients, those with a CHADS2 score of > 3 (barring excellent INR control) and for lower-risk patients with a CHADS2 of 2 but concomitant high risk of hemorrhage. In addition, factor Xa inhibitors, such as rivaroxaban (recently approved by the Federal Drug Administration [FDA]) and apixaban, may exhibit the same cost savings as dabigatran in terms of reduction of bleeding and elimination of therapeutic level monitoring costs. Going forward, the use of these agents and their role in thromboembolic stroke prophylaxis will need to be evaluated on a patient-by-patient basis, balancing consideration of the patient’s stroke and bleeding risks, as well as quality of life post-therapy.

Monday, August 12, 2013

Atrial Fibrillation in Acute Coronary Syndrome

Citation : Jason C. Rubenstein, Michael P. Cinquegrani, Jennifer Wright

Atrial fi brillation (AF) is a common cardiac arrhythmia occurring in an estimated 2.7 to 6.1 million people in the United States. The risk factors for the development of AF are very similar to those for developing coronary artery disease, and AF is often associated with acute coronary syndrome (ACS) and acute myocardial infarction (MI). Overall, AF complicates approximately 10% of acute infarcts and the incidence rate is comparable between the thrombolytic and percutaneous coronary intervention (PCI) eras. Prior to widespread use of thrombolysis, the incidence of AF during acute MI was as high as 18%. Moreover, AF is a marker for increased long term mortality post infarct. Over the past 20 years, the relative mortality risk for patients with AF post MI has remained around 2.5 times that for patients without AF.

The treatment of AF in the setting of MI and ACS is similar to without; however there is often an increased urgency to limiting rapid heart rates which may exacerbate acute ischemia. Cardioversion and IV amiodarone may be utilized more liberally in this setting than otherwise. Anticoagulation is usually required both for the treatment of MI and possible PCI, as well as for cerebral vascular accident prevention from AF-induced thromboembolism. Often patients require triple-therapy for optimal treatment of both conditions, and special considerations for bleeding risk must be analyzed.

Stroke and Death Prediction with the Impact of Vascular Disease in Patients with Atrial Fibrillation

Citation : Abhishek Maan, Amir Y. Shaikh, Moussa Mansour, Jeremy N. Ruskin, E. Kevin Heist

Atrial fibrillation (AF) is the most common arrhythmia encountered in the U.S. and the growing burden of AF has profound health implications due to the association of AF with an increased risk of stroke, heart failure, and mortality. AF is a significant risk factor for thromboembolic stroke; and also independently increases total mortality in patients with and without cardiovascular disease. Various risk stratification schemes such as CHADS2 and CHA2DS2-VASc have been implemented in clinical practice to determine the risk of cardio-embolic stroke, and need for thrombo-prophylaxis in patients with AF. AF is also closely related to the pathophysiology of other cardiovascular and peripheral vascular disease. Many patients with AF have associated atherosclerosis given that many risk factors for atherosclerosis also predispose to AF. Myocardial infarction (MI) is also closely related to AF and its clinical course is affected by new onset AF. This review elucidates the impact of AF on major adverse cardiovascular events and mortality outcomes in relation to stroke, coronary artery disease and peripheral vascular disease.

Multi-Electrode Ablation Catheters for AF Ablation: Effective Reality or Elegant Experiment?

Citation : Lucas Boersma

The landmark publication by Haissaguerre et al. in 1998 on ablation of PV foci to cure AF, has led the way for a global rise of pulmonary vein isolation for ablation for AF.1 Nowadays in many centres this comprises half of all ablations performed. In 2007, a consensus document was published by Calkins et al.2 on behalf of HRS and EHRA to provide guidelines on how to perform procedures and how to determine efficacy. This has led to a new appreciation of historical data, and more vigorous and longer-term evaluation of patients after ablation for AF.

Atrial Fibrillation at an Internal Medicine Ward: Clinical and Prognostic Implications

Citation : Miriam Shteinshnaider, Dorit Almoznino-Sarafian, Irena Alon, Irma Tzur, Sylvia Berman, Natan Cohen, Oleg Gorelik

Background: Little is known about atrial fibrillation (AF) appearing during hospitalization in an Internal Medicine ward.

Purpose: We aimed to investigate characteristics and prognostic significance of in-hospital onset AF.
Methods: We studied 249 consecutive unselected patients admitted to this medical department with paroxysmal or persistent AF (out-of-hospital group) or AF developed during hospitalization (in-hospital group). Demographic, clinical, laboratory, electrocardiographic and echocardiographic data and all-cause mortality following discharge were recorded and compared between the groups
Results: Diabetes mellitus (p=0.05), renal dysfunction (p<0.001), chronic lung disease (p=0.03) and history of stroke (p=0.01) were found more common in the in-hospital group (56 patients), compared to the out-of-hospital group (193 patients). Patients from the in-hospital group were more likely to have recurrent episodes of AF during hospitalization (p=0.002), were more frequently treated with amiodarone (p<0.001), discharged in sinus rhythm (p=0.04) and with medications for rhythm control (p=0.04). Time from onset to termination of AF (p<0.001) and hospital stay (p<0.001) were longer in the in-hospital group. On a median of 39-months follow-up, survival rate was lower in the in-hospital vs. out-of-hospital group (69.6% vs. 81.3%, p=0.025). Older age was significantly associated with shorter survival in the in-hospital group [odds ratio (OR)=1.87, 95% confidence interval (CI) 1.15−3.03, p=0.009]. In the out-of-hospital group, advanced age (OR=2.17, 95%CI 1.51−3.10, p<0.001), no prior AF episode (OR=3.41, 95%CI 1.56−7.46, p=0.002), diabetes mellitus (OR=2.22, 95%CI 1.12−4.39, p=0.006) and renal dysfunction (OR=2.44, 95%CI 1.10−5.38, p=0.049) were significantly associated with shorter survival.

Transient ST Elevation in Vagally Mediated Atrial Fibrillation

Citation : Constantinos Makrides

We report a case of vagally mediated atrial fibrillation on a young otherwise healthy man, with straight type ST-segment elevation in inferolateral leads that resolved a few hours after restoration of sinus rythm, a phenomenon that has never been previously reported. Even though no definite conclusion about the underlying mechanism of the ST-elevation can be made, this effect might probably be the result of intense parasympathetic tone and could be used to differentiate the causality.

Sunday, August 11, 2013

Statin and Atrial Fibrilation; When does it work?

Citation : Laurent Fauchier, Nicolas Clementy, Bertrand Pierre, Dominique Babuty

In the recent years, some clinical and experimental studies have suggested that the use of statins may protect against atrial fibrillation (AF). A relation between inflammation and the development of AF has been described, and the potent anti-inflammatory and antioxidant properties of statins may make them effective in preventing the development of AF. A global analysis of the literature suggests that the use of statins is associated with a decreased risk of incidence or recurrence of AF in some cases. However, this beneficial effect is not seen for all types of AF in all the patients. The use of statins seems associated 1) with a lack of benefit in primary prevention of AF, 2) with a significant but heterogeneous decreased risk of recurrence of AF in secondary prevention, and 3) with a very significant and homogeneous reduction for the risk of post operative AF. An intensive lipid lowering statin regimen does not provide greater protection against AF. Patients with coronary heart disease are currently treated with statins in most cases, and this may not have an impact on their treatment. In contrast, it remains to determine more accurately if statins may bring a significant benefit for some AF patients without any type of established atherosclerotic disease or with a low risk of atherogenesis. Since it remains uncertain whether the suppression of AF in these patients is beyond doubt beneficial, prescribing statins for this purpose alone should not be recommended at the present time.

Apixaban in patients with Atrial Fibrillation: A Systematic Review

Citation : Abhishek Maan, E.Kevin Heist, Amir Y. Shaikh, Jeremy N. Ruskin, Moussa Mansour

Atrial fibrillation (AF) is the most common cardiac arrhythmia which increases the risk of stroke and systemic embolism by 5- fold, it is a major global public health problem. Stroke is associated with greatest mortality and morbidity in patients with AF. Strokes associated with AF are especially large and disabling, and consequently primary prevention is paramount. Antithrombotic therapy is the mainstay of stroke prevention. Vitamin K antagonists (VKA’s) have been the standard anticoagulants in stroke prophylaxis for patients with AF for decades. Despite their effectiveness, they are limited by several factors such as narrow therapeutic index, drug- drug interactions, slow onset and offset of action, hemorrhage and routine anticoagulation monitoring to maintain therapeutic international normalized ratio (INR). During recent times, various novel anticoagulants have been developed to expand the therapeutic option for stroke prevention. Apixaban is a novel oral anticoagulant which has been developed and clinically investigated for prevention of stroke in AF patients. This review discusses the pharmacological properties, results of clinical trials investigating role of apixaban for prevention of stroke and its future potential in clinical practice.

Effect of Omega-3 Polyunsaturated Fatty Acid Supplementation in Patients with Atrial Fibrillation

Citation : Sanjay Kumar, Sarah Qu, John T. Kassotis

Atrial fibrillation (AF) is the most common sustained atrial arrhythmia conferring a higher morbidity and mortality. Despite the increasing incidence of AF; available therapies are far from perfect. Dietary fish oils, containing omega 3 fatty acids, also called polyunsaturated fatty acid [PUFA] have demonstrated beneficial electrophysiological, autonomic and anti-inflammatory effects on both atrial and ventricular tissue. Multiple clinical trials, focusing on various subsets of patients with AF, have studied the role of PUFA and their potential role in reducing the incidence of this common arrhythmia. While PUFA appears to have a beneficial effect in the primary prevention of AF in the elderly with structural heart disease, this benefit has not been universally observed. In the secondary prevention of AF, PUFA seems to have a greater impact in the reducing AF in patients with paroxysmal or persistent AF, stages of AF associated with less atrial fibrosis and negative structural remodeling. However, AF suppression has not been consistently demonstrated in clinical trials. In patients undergoing heart surgery, increasing PUFA intake has yielded mixed results in terms of AF prevention post-operatively; however, increased PUFA has been associated with a reduction in hospital stay. Therefore recommending the use of PUFA for the purpose of AF reduction remains controversial. This is in part attributable to the complexity of AF. Other conflicting variables include: heterogeneous patient populations studied; variable dosing; duration of follow-up; comorbidities; and, concomitant pharmacotherapy. This review article reviews in detail available basic and clinical research studies of fish oil in the treatment of AF, and its role in the treatment of this common disorder.

The Role of Atrial Structural Remodeling in Atrial Fibrillation Ablation:An Imaging Point of View For Predicting Recurrence

Citation : Yasushi Akutsu, FESC, Kaoru Tanno, Youichi Kobayashi

Atrial fibrillation (AF) is the most common arrhythmia and is associated with a significant morbidity and mortality. Invasive catheter ablation of AF has emerged as an effective therapy for patients with symptomatic AF. Atrial remodeling, particularly structural remodeling, is important not only for AF persistence but also for AF recurrence after ablation. Atrial dilation and fibrosis are two of the core processes involved in atrial structural remodeling. Increased automaticity and triggered activity occur in atrial structural remodeling, which may cause difficulty in maintaining sinus rhythm after ablation. Furthermore, an enlarged left atrium (LA) may increase the difficulty in achieving catheter stability and thereby require more energy to complete AF ablation. AF causes similar remodeling in both the left and right atria (RA), and myocardial changes in both atria influence AF recurrence. A non-invasive assessment of fibrotic structural remodeling helps predict the outcome of AF ablation. A variety of cardiac imaging modalities, such as two- or three-dimensional echocardiography or multi-detector row computed tomography, have been used to estimate the magnitude of atrial structural remodeling by measuring atrial volume or LA function. Furthermore, delayed enhanced cardiac magnetic resonance imaging has been used to detect not only atrial fibrosis but also the effect of the ablation point. Thus, atrial remodeling, particularly structural remodeling, plays an important role in AF recurrence. These non-invasive imaging modalities are significant tools for estimating atrial enlargement to improve patient selection for AF ablation at the point of paroxysmal AF, and for estimating atrial fibrosis to select the AF treatment including ablation strategy at the point of development to persistent or permanent AF.

Role of Cardiac Imaging (CT/MRI) Before and After RF Catheter Ablation in Patients with Atrial Fibrillation

Citation : Aravindan Kolandaivelu

Pre-procedure X-ray computed tomography (CT) and magnetic resonance imaging (MRI) angiography are commonly used to delineate the complex and variable relationship of the left atrium, pulmonary veins, and surrounding structures. 3D CT and MR angiography are routinely incorporated into electroanatomic mapping systems to guide ablation lesion placement in the context of patient specific anatomy. Post-procedure CT and MRI have also proven useful for evaluating complications such as pulmonary vein stenosis. In the future, these imaging modalities may be used to visualize more detailed tissue characteristics such as atrial fibrosis and ablation lesions. This could improve selection of patients for different treatment strategies and perhaps guide more effective ablation. This review will discuss current and emerging applications of CT and MRI before and after radiofrequency catheter ablation of atrial fibrillation.

Saturday, August 10, 2013

Post Ablation Left Atrial Tachycardia: Understanding mechanism, prevention and treatment.

Citation : Carlo Pappone, Vincenzo Santinelli

Currently, post-ablation Atrial Tachycardias (ATs) represent a growing clinical problem particularly in patients with persistent AF undergoing a more extensive substrate ablation. Understanding mechanisms and location of potentially widely located arrhythmogenic substrates in the left atrium is crucial for successful ablation. Mapping and ablation are challenging since complex and multiple ATs may frequently develop during the index procedure and before conversion to sinus rhythm. Use of irrigated ablation guided by detailed 3-D electroanatomic activation maps combined with entrainment pacing is effective with excellent acute and long-term success rates, rarely requiring multiple procedures.

Should Atrial Fibrillation Burden Be A Feature to Guide Thromboembolism Prophylaxis?

Citation : Molly Sachdev, Emile G. Daoud

Atrial fibrillation (AF) is a well-known risk factor for cerebrovascular events and systemic emboli. However, the frequency and duration of AF necessary to be considered at risk for thrombus formation is unknown. This review summarizes the literature regarding AF burden and risk for thromboembolism. Previously, no distinction was made between patients who had paroxysmal versus persistent AF in regards to initiation of anticoagulation. Recently though, given an enhanced ability to detect even very brief paroxysms of AF via stored device diagnostics, the issue has been readdressed. However, despite multiple studies no clear threshold for AF burden to mandate anticoagulation has been established. In addition, there is a growing body of evidence which suggests that the pathophysiology of thrombus formation in AF involves mechanisms beyond just stasis due to protracted episodes of discoordinate atrial contraction. Therefore, once AF has been diagnosed and the risk-benefit ratio favors anticoagulation, therapy should be initiated and continued indefinitely unless a bleeding contraindication develops.

Primary Prevention of Atrial Fibrillation where are we in 2012?

Citation : Massimo Imazio

Drugs to alter or delay myocardial remodelling associated with heart failure, hypertension, or inflammation in the post-operative setting, may prevent the development of atrial fibrillation. Current experimental and clinical evidences support specific treatments for defined patient population (i.e. ACE-inhibitors and ARB for chronic heart failure and hypertension expecially with LV hypertrophy; statins, corticosteroids and possibly colchicine after cardiac surgery).

Echocardiography In the Prediction of Atrial Fibrillation Recurrence: A Review

Citation : Maria Caputo, Sergio Mondillo

Atrial fibrillation (AF) is a very common sustained arrhythmia. Co-morbidities and age signifi cantly accelerate the progression of AF to persistent and permanent forms and the development of complications. The rate of AF recurrence is 10% in the fi rst year after the initial diagnosis (25–50% in the first month after restoration of sinus rhythm) and about 5% per annum thereafter. Left ventricular (LV) diastolic dysfunction degree has been associated with new-onset AF and in the last few years many new parameters to evaluate diastolic function were introduced and validated, even in patients with AF.

Aim of this review was to summarize echocardiographic parameters, focusing on new tools, to evaluate patients with AF and to explore the role of echocardiographic evaluation to predict recurrence of the arrhythmia.

Microwave Ablation in Mitral Valve Surgery for Atrial Fibrillation (MAMA)

Citation : Anders Jönsson, Mika Lehto, Henrik Ahn, Ulf Hermansson, Peter Linde, Anders Ahlsson, Juhani Koistinen, Jukka Savola, Pekka Raatikainen, Martti Lepojärvi, Antero Sahlman, Kalervo Werkkala, Lauri Toivonen, Håkan Walfridsson

Objective: Microwave ablation in conjunction with open heart surgery is effective in restoring sinusrhythm (SR) in patients with atrial fibrillation (AF). In patients assigned for isolated mitral valve surgery no prospective randomized trial has reported its efficacy.

Methods: 70 patients with longlasting AF where included from 5 different centres. They were randomly assigned to mitral valve surgery and atrial microwave ablation or mitral valve surgery alone.

Results: Out of 70 randomized, 66 and 64 patients were available for evaluation at 6 and 12 months. At 12 months SR was restored and preserved in 71.0 % in the ablation group vs 36.4 % in the control group (P=0.006), corresponding figures at 6 months was 62.5 % vs 26.5 % (P=0.003). The 30-day mortality rate was 1.4 %, with one death in the ablation group vs zero deaths in the control group. At 12 months the mortality rate was 7,1 % (Ablation n=3 vs Control n=2). No significant differences existed between the groups with regard to the overall rate of serious adverse events (SAE) during the perioperative period or at the end of the study. 16 % of patients randomized to ablation were on antiarrhytmic drugs compared to 6 % in the control group after 1 year (p=0.22)

Conclusion: Microwave ablation of left and right atrium in conjunction with mitral valve surgery is safe and effectively restores sinus rhythm in patients with longlasting AF as compared to mitral valve surgery alone.

Wednesday, August 7, 2013

Remote Magnetic Navigation System Guided Radiofrequency Ablation of Intra Atrial Reentrant Trachycardia in Corrected Transposition of Great Arteries

Citation : Hemant Boolani, Yeruva Madhu Reddy, Esam Baryun, Brandon Barnds, Pramod Janga, Hema Pamulapati, Dhanunjaya Lakkireddy

Atrial arrhythmias are delayed manifestations after atrial switch procedures for d-transposition of the great arteries. Often times, these arrhythmias are intraatrial reentry tachycardias that arise in the pulmonary venous neo-atrium. Access and ablation in the pulmonary venous neo-atrium may require baffle puncture, risking damage to the baffle. We describe a case of neoatrial arrhythmia ablation in d-transposition of the great arteries using remote magnetic guided catheter navigation system using a retrograde approach without doing a baffle puncture.

The Use of Ranolazine in the Management of Recurrent Atrial Fibrillation After Percutaneous Radiofrequency Ablation

Citation : Angelo Biviano, Cristobal Goa, Sam Hanon, James Reiffel

Long-term medical treatment options for atrial fibrillation (AF) include rate-control as well as rhythm-control therapy with various antiarrhythmics. However, because of the limited efficacy and potential side effects of these medications, percutaneous and surgical ablations in AF patients have evolved as alternative or additional approaches to achieve rhythm-control. Nonetheless, arrhythmia recurrences may also occur after these procedures. Thus, the search for complementary treatment options continues. Ranolazine possesses antiarrhythmic effects in atrial myocytes via blockade of sodium channels. These properties facilitate AF suppression in animal models and human subjects. We report a patient with persistent AF that was refractory to medical management and percutaneous catheter ablation. She has remained in sinus rhythm for at least 18 months after the initiation of ranolazine.

Impact of Atrial Fibrillation on Coronary Blood Flow: A Systematic Review

Citation : George E. Kochiadakis, Eleftherios M. Kallergis

Patients with atrial fibrillation (AF) frequently present with symptoms suggestive of myocardial ischaemia, even in the absence of significant CAD, that seem to be attributable to abnormalities of myocardial perfusion and perfusion reserve. According to the results of recent human and previous experimental studies the increase in coronary artery blood flow during AF is smaller, while the coronary vascular resistance during the arrhythmia does not decrease as much as we would expect, suggesting a mismatch between coronary blood flow and myocardial metabolic demand. AF itself diminishes coronary flow reserve, especially in the subendocardial layer, partly as a result of the increase in the myocardial component of coronary vascular resistance, and it is possible that irregular ventricular rhythm may play an important role. The mismatch of coronary blood flow and myocardial metabolic demand, especially in view of the severe reduction in coronary flow reserve, may have deleterious consequences that are not limited to patients with CAD.

Atrial Fibrillation and the Role of LAA in Pathophysiology and Clinical Outcomes?

Citation : Serkan Saygi

Left atrial appendage (LAA) is a source of thromboembolism especially in patients with non valvular atrial fibrillation (AF). It is reasonable to accept LAA as a distinct part of left atrium (LA) with unique anatomical and physiological properties. Advances in imaging modalities increased the knowledge about anatomical and physiological characteristics of LAA. It is important to prevent the AF patients from systemic thromboembolic events, and new pharmacological and non pharmacological management approaches demonstrate encouraging results. Also pulmonary vein isolation which has been accepted as a curative and useful treatment option for the treatment of drug resistant AF has been helpful in understanding the electrophysiological properties of LAA. Accumulating data revealed that LAA continues to be the one of the most important structure of heart during AF because of its distinctive anatomical, mechanical, and electrophysiological properties.

Mortality Risk Associated with AF in Myocardial Infarction Patients

Citation : Rajiv Sankaranarayanan

Atrial fibrillation (AF) complicating myocardial infarction (MI) has been a controversial topic for the last few decades. It has generated a plethora of debates regarding whether it is a risk indicator of co-morbidities and poor haemodynamic status or independent causal mediator of poor outcomes. The management of this condition has also been idiosyncratic probably due to confusion regarding its prognostic significance. We shall review the literature and attempt to elucidate the prognostic significance as well as evidence available for defining management strategies.

Tuesday, August 6, 2013

Predictors of Recurrence After Radiofrequency Ablation of Persistent Atrial Fibrillation

Citation : Miki Yokokawa, Hakan Oral, Aman Chugh

Radiofrequency catheter ablation that targets the pulmonary veins is well established as a mainstay for drug-refractory, paroxysmal atrial fibrillation (AF). However, in patients with persistent AF, the ideal approach remains elusive. Further, despite the various additional ablation strategies that have been investigated in patients with persistent AF, the rate of recurrent atrial tachyarrhythmias after ablation remains relatively high. In this review, the predictors of recurrent atrial tachyarrhythmias after catheter ablation of persistent AF will be discussed.

Should Physicians Continue to Recommend Fish Oil for Patients with Atrial Fibrillation?

Citation : Victoria M. Robinson, Peter R. Kowey

Many physicians recommend the use of fish oil or omega-3 polyunsaturated fatty acids (n-3 PUFA) in atrial fibrillation (AF) patients. N-3 PUFA have demonstrated anti-fibrillatory properties in several animal studies, however, data regarding their efficacy in preventing AF in humans have been mixed. This article critically reviews studies that have investigated the use of n-3 PUFA for the secondary prevention of paroxysmal and persistent AF and the primary prevention of post-operative AF. We conclude that n-3 PUFA should no longer be recommended for use in any of these AF subtypes until more data are available.

The Impact of Atrial Fibrillation Ablation on Quality of Life

Citation : Jacob Pontoppidan

Quality of life (QoL) is a very important endpoint in trials reporting the efficacy of catheter ablation in patients with atrial fibrillation (AF). It has been shown that AF ablation significantly improves the QoL, but recent studies question the usefulness of the most used generic QoL instrument in AF patients. The complexity of the disease makes it mandatory to employ disease specific instruments in the assessment of QoL. This paper reviews the current knowledge of various QoL instruments, including the limitations and pitfalls, and the impact of AF ablation on the QoL

Atrial Fibrillation Complicating Acute Coronary Syndromes

Citation : Sean D. Pokorney, Meena Rao, Kent R. Nilsson, Jonathan P. Piccini

Atrial fibrillation frequently complicates myocardial infarction. Patients with atrial fibrillation complicating acute coronary syndrome have increased morbidity and mortality relative to patients that remain in normal sinus rhythm. No studies have identified a mortality benefit to rhythm control compared with rate control in the setting of acute coronary syndrome. Stroke prevention should be pursued with oral anticoagulation therapy, although the majority of patients with atrial fibrillation associated with acute coronary syndrome receive only antiplatelet therapy. There are several novel oral anticoagulant therapies now available, but these agents have not been well studied in combination with dual antiplatelet therapy. Therefore, warfarin as part of triple therapy is the most conservative approach until additional data becomes available.

Atrial Fibrillation and Metabolic Syndrome: Understanding the Connection

Citation : Prabhat Kumar, Anil K. Gehi

Metabolic syndrome, a constellation of conditions including obesity, dyslipidemia, hypertension and insulin resistance, has increased to epidemic proportions. Metabolic syndrome has been recognized as a risk factor for cardiovascular morbidity and is likely related to the epidemic of cardiovascular diseases. Perhaps not coincidentally, its growth in incidence has paralleled that of atrial fibrillation. Various components of metabolic syndrome have been known to have a role in the pathogenesis of atrial fibrillation. With the conglomeration of components seen in the metabolic syndrome, the risk for atrial fibrillation increases greatly. Several studies have elucidated the role of metabolic syndrome in the development of atrial fibrillation. Its role on the atrial substrate makes it an important determinant of progression of disease and failure of therapeutic strategies such as catheter ablation. Control of the various components of metabolic syndrome may ultimately lead to better outcomes in atrial fibrillation patients.

AF and Venous Thromboembolism – Pathophysiology, Risk Assessment and CHADS-VASc score

Citation : Nasir Shariff, Abdul Aleem, Mukesh Singh, Yuan Z. Li, Stacey J Smith

Atrial fibrillation (AF) and venous thromboembolism (VTE) are the two most common medical conditions managed with anti-coagulation therapy. Not all the patients with decreased mobility or AF have a similar risk for thromboembolism. The risk factors for venous thromboembolism and thromboembolism associated with AF are described in various studies. Considering that the two conditions have similar pathophysiologic basis of clot formation, one could imply that the risk factors for the occurrence of thrombosis could be similar. The present review focuses on the similarities and differences in the clinical risk factors of VTE and AF related thromboembolism. We will also be discussing the role of CHADS2-VASc scoring system in the risk assessment of VTE.

Review of Predictive and Preventative Factors of Atrial Fibrillation Post Cardiac Surgery

Citation : Saina Attaran , Prakash P Punjabi, Jon Anderson

Background: Post cardiac surgery atrial fibrillation is common after cardiac surgery. Despite the advances in medical and surgical treatment, its incidence remains high and unchanged for decades. The aim of this review was to summarize studies published in 2011 on identifying factors, prevention strategies, treatment and effect of post operative atrial fibrillation (POAF) on the outcome after cardiac surgery.

Methods: A review was performed on Medline, Embase and Chocrane on all of the English-language, peer-reviewed published clinical studies on POAF; studies investigating the mechanism of developing POAF, prevention, treatment and outcome were all included and analyzed. Case reports, studies on persistent/preoperative atrial fibrillation (AF), POAF after cardiac transplant, congenital cases and nonclinical studies were all excluded. We have also valuated these studies based on the type of the study, their originality, impact factor of the journal and their limitations.

Results: Overall 62 studies were reviewed and analyzed; 26 on POAF predictive factors, 31 on preventative strategies and 6 on the outcome of POAF. Of these studies only two were original and the remaining were either performed in AF in general population (n=10) or had been studied and reported several times before in cardiac surgery (n=50). The average impact factor of the journals that POAF was published in was only 2.8 ranging between 0.5 and 14.5.

Conclusion: Post cardiac surgery atrial fibrillation is a multi-factorial and complex condition. Cardiac surgery may be a risk factor for developing POAF in patients already susceptible to this condition and may not be a complication of cardiac surgery. Future studies should mainly focus on histological changes in the conductive tissue of atrium and related treatment strategies rather than predictive factors of POAF and more funding should be made available to study this condition from new and entirely different perspectives.

Solutions to Reduce Cardiovascular Events in Patients with Atrial Fibrillation

Citation : Maurizio Paciaroni and Giancarlo Agnelli

AF is the most common sustained cardiac rhythm disorder and an established risk factor for ischemic stroke. Ischemic strokes which occur in patients with AF are particularly severe and disabling. In addition, stroke recurrence is more common in patients with AF compared with those without it. Previous cerebrovascular events, age, hypertension, diabetes, and heart failure are risk factors for stroke in patients with AF.

Various risk stratification schemes have been developed to quantify the risk for stroke in patients with AF. Currently, the most frequently used schemes to assess stroke risk in patients with AF are CHADS2, the ACC/AHA/ESC and American College of Chest Physicians (ACCP) schemes.
Current risk scores are largely derived from risk factors identified from clinical trials and many potential risk factors have not been properly considered. Consequently, the stroke risk in many patients could be underestimated, and these patients could receive a suboptimal antithrombotic prophylaxis.

There is substantial evidence for the benefit of vitamin K antagonists (VKA) in preventing stroke and reducing mortality. Novel oral anticoagulants are available for stroke prevention in patients with AF which overcome some of the difficulties associated with VKA. The introduction of novel oral anticoagulants in clinical practice and the advances in identifying patients at risk of stroke together may overcome many of the difficulties in providing effective stroke prevention for patients with AF.