Thursday, December 11, 2008

Atrial Fibrillation: a Patient’s Guide to Understanding Drug Therapy


Citation : Ragini Bhakta.Atrial Fibrillation: a Patient’s Guide to Understanding Drug Therapy .JAFIB.2008 Dec;Volume 1 Issue(4): 255-256.

Atrial Fibrillation (AF) as defined by the American Heart Association is an irregular heart beat (rhythm) where the small upper chambers of the heart (atria) beat ineffectively. The atria cannot pump all of the blood out of the chambers, resulting in pooling of the blood or clot formation. Unfortunately, if a part of the clot leaves the atria, it can become lodged in an artery in the brain resulting in an ischemic stroke.

The A That Did Not Fib: Two Roads Both Traveled By


Citation : James C. Hansen,Abraham G. Kocheril.The A That Did Not Fib: Two Roads Both Traveled By .JAFIB.2008 Dec;Volume 1 Issue(4): 250-254.

Case: A 64-year-old woman presented with palpitations. Her 24-hour Holter monitor revealed runs of presumed atrial fibrillation (AF). The patient was referred for EP study and AF ablation.

EPS: At EPS, an anterograde A-H jump was noted. Spontaneous bursts of tachycardia were seen, consisting of sinus atrial beats with dual ventricular responses, each preceded by a His deflection. There was no atrial fibrillation during the study. Radiofrequency ablation of the slow AV node pathway was performed. There were no inducible tachycardias and no A-H jump following the ablation. The patient had no recurrence post-procedure.

Discussion: This case presents a rare example of simultaneous dual anterograde AV-nodal conduction. The conditions leading to this phenomenon include dual AVN pathways, markedly slowed conduction in the slow pathway, and lack of retrograde conduction up either pathway such that reentry was impossible. An irregular, narrow-complex tachycardia resulted, initially interpreted as AF. Slow-pathway ablation was curative.

The Anticoagulated Atrial Fibrillation Patient Who Requires “Curative” Therapy for Prostate Carcinoma: a Bleeding Conundrum


Citation : James A.Reiffel.The Anticoagulated Atrial Fibrillation Patient Who Requires “Curative” Therapy for Prostate Carcinoma: a Bleeding Conundrum .JAFIB.2008 Dec;Volume 1 Issue(4): 248-249.

With the aging of the population, the incidence of both prostate carcinoma (PCa) and atrial fibrillation (AF) has increased. Options for “curative therapy” PCa now include surgery, external beam radiation (EBT), and radioactive seed implantation (RSI). The latter two approaches, especially EBT, can produce radiation proctitis (RP) with rectal bleeding (RB). This poses an issue for anticoagulating the elderly AF patient who develops PCa. The attached case report of a 77 year old male who was treated with a combination of RSI and “low dose” EBT followed by recurrent severe rectal bleeding demonstrates the significance of this problem. In the AF patient with a CHADS2 score of 2 or more, and hence an indication for chronic warfarin therapy, the therapy of subsequently detected PCa requires careful consideration of the risks associated with its therapeutic options.

Is Rhythm Control with Pulmonary Vein Isolation Superior to Rate Control with AV Nodal Ablation in Patients with Heart Failure?


Citation : Dhanunjaya Lakkireddy.Is Rhythm Control with Pulmonary Vein Isolation Superior to Rate Control with AV Nodal Ablation in Patients with Heart Failure? .JAFIB.2008 Dec;Volume 1 Issue(4): 246-247.

BACKGROUND: Pulmonary-vein isolation is increasingly being used to treat atrial fibrillation in patients with heart failure. METHODS: In this prospective, multicenter clinical trial, we randomly assigned patients with symptomatic, drug-resistant atrial fibrillation, an ejection fraction of 40% or less, and New York Heart Association class II or III heart failure to undergo either pulmonary-vein isolation or atrioventricular-node ablation with biventricular pacing. All patients completed the Minnesota Living with Heart Failure questionnaire (scores range from 0 to 105, with a higher score indicating a worse quality of life) and underwent echocardiography and a 6-minute walk test (the composite primary end point). Over a 6-month period, patients were monitored for both symptomatic and asymptomatic episodes of atrial fibrillation. RESULTS: In all, 41 patients underwent pulmonary-vein isolation, and 40 underwent atrioventricular-node ablation with biventricular pacing; none were lost to follow-up at 6 months. The composite primary end point favored the group that underwent pulmonary-vein isolation, with an improved questionnaire score at 6 months (60, vs. 82 in the group that underwent atrioventricular-node ablation with biventricular pacing; P<0.001), a longer 6-minute-walk distance (340 m vs. 297 m, P<0.001), and a higher ejection fraction (35% vs. 28%, P<0.001). In the group that underwent pulmonary-vein isolation, 88% of patients receiving antiarrhythmic drugs and 71% of those not receiving such drugs were free of atrial fibrillation at 6 months. In the group that underwent pulmonary-vein isolation, pulmonary-vein stenosis developed in two patients, pericardial effusion in one, and pulmonary edema in another; in the group that underwent atrioventricular-node ablation with biventricular pacing, lead dislodgment was found in one patient and pneumothorax in another. CONCLUSIONS: Pulmonary-vein isolation was superior to atrioventricular-node ablation with biventricular pacing in patients with heart failure who had drug-refractory atrial fibrillation. (ClinicalTrials.gov number, NCT00599976.) 2008 Massachusetts Medical Society

Do Statins Decrease the Arrhythmia Burden in Patients with Paroxysmal Atrial Fibrillation?


Citation : Dhanunjaya Lakkireddy.Do Statins Decrease the Arrhythmia Burden in Patients with Paroxysmal Atrial Fibrillation? .JAFIB.2008 Dec;Volume 1 Issue(4): 244-245.


Role of the Autonomic Nervous System in the Creation of Substrate for Atrial Fibrillation


Citation : Rishi Arora,Alan H. Kadish.Role of the Autonomic Nervous System in the Creation of Substrate for Atrial Fibrillation .JAFIB.2008 Dec;Volume 1 Issue(4): 236-243.

Atrial fibrillation (AF) is the most common sustained arrhythmia disturbance and is associated with significant morbidity and mortality. In recent years, the pulmonary veins (PVs) and posterior left atrium (PLA) have been shown to play a significant role in the genesis of AF.


These regions have been shown to possess unique structural, electrophysiological and calcium (Ca2+) handling characteristics, all of which appear to contribute to substrate for AF.


The pathophysiology of AF is complex, and several mechanisms have been thought to contribute to the electrophysiologic and structural substrate for this arrhythmia. These mechanisms include fibrosis, stretch, inflammation and oxidative stress. In addition, neurohumoral factors have also been invoked for their possible contribution to the creation of electrophysiologic substrate for AF [3, 4]. An important neurohumoral factor that has been studied fairly extensively for its involvement in AF is the autonomic nervous system.

Typical flutter ablation as an adjunct to catheter ablation of atrial fibrillation


Citation : Dipen Shah.Typical flutter ablation as an adjunct to catheter ablation of atrial fibrillation .JAFIB.2008 Dec;Volume 1 Issue(4): 230-235.

Typical atrial flutter and atrial fibrillation are frequently observed to coexist(1) . In the current context of interventional electrophysiology, curative or at least definitive ablation is available for both arrhythmias. Despite their coexistence, it is not clear whether typical flutter ablation is necessary in all patients undergoing catheter ablation of atrial fibrillation. The following review explores the pathophysiology of both arrhythmias, their interrelationships and the available data pertaining to this theme.

Catheter Ablation for AF: Past, Present, and Future


Citation : David Spragg,Hugh Calkins.Catheter Ablation for AF: Past, Present, and Future .JAFIB.2008 Dec;Volume 1 Issue(4): 221-229.

Atrial fibrillation (AF) is the most common sustained tachyarrhythmia encountered by physicians. The prevalence of AF in patients over the age of 65 is approximately 6%, and approaches 10% in patients over the age of 85. As the median age of the population in the United States becomes older, the epidemiologic burden of AF in this country will likely increase. Currently approximately 2.2 million people in the United States have AF. AF, while typically not a life-threatening arrhythmia per se, is associated with increased risk of stroke, heart failure, and increased mortality. The stroke risk in patients with AF, for instance, is increased between 5- and 7-fold compared to similar patients without AF.

Periablative Anticoagulation Strategies in Patients with Atrial Fibrillation


Citation : Fernanda d’Araujo Costa Ferreira, Eduardo B. Saad.Periablative Anticoagulation Strategies in Patients with Atrial Fibrillation .JAFIB.2008 Dec;Volume 1 Issue(4): 216-220.

Atrial fibrillation is associated with thromboembolic events that may cause important impairment on quality of life. Pulmonary vein isolation is the treatment of choice in cases that are refractory to medical therapy. Once sheaths and catheters are manipulated inside the left atrium, anticoagulation with heparin must be used during the procedure to protect patients from thromboembolic phenomena. Different strategies of anticoagulation are used at different centers. This review summarizes the pathophysiology of thrombus formation in the left atrium, defines which patients are under high risk and describes the main strategies used for anticoagulation.


Extraatrial Disease in Patients with “Lone” Atrial Fibrillation


Citation : Jason Confino,Daniel Edmundowicz,Joan M. Lacomis,Iclal Ocak, Christopher R. Deible,David Schwartzman.Extraatrial Disease in Patients with “Lone” Atrial Fibrillation .JAFIB.2008 Dec;Volume 1 Issue(4): 209-215.

Aims: Lone atrial fibrillation (LAF) is considered by some to be a primary atrial electrophysiologic disorder. However, we have frequently observed evidence of “extraatrial” diseases - atherosclerosis and associated metabolic disorders - in our LAF patients. We sought to characterize and quantify extraatrial disease burden in LAF patients, and to correlate this burden with features of the arrhythmia including pattern (paroxysmal versus persistent) and response to catheter ablation.

Methods and Results: Forty-six consecutive patients with non-familial LAF underwent assessment for evidence of atherosclerosis (computed tomographic vascular calcification and elevated arterial pulse wave velocity) and associated metabolic diseases (dyslipidemia, insulin resistance and inflammation), and then catheter ablation.

The cohort had a significant incidence of atherosclerosis (57%) and metabolic (70%) diseases. Patients with persistent AF tended to have a greater extraatrial disease burden than those with paroxysmal AF. A significant inverse relationship between the rate of ablation success and extraatrial disease burden was demonstrated.

Conclusions: Extraatrial disease was common in this LAF cohort. Correlations between extraatrial disease burden and features of the arrhythmia would, if verified, challenge the notion that LAF is a “primary” electrophysiologic disorder.

Quality of Life, Exercise Capacity and Comorbidity in Old Patients with Permanent Atrial Fibrillation


Citation :Inger Ariansen,Knut Gjesdal, Michael Abdelnoor, Elisabeth Edvardsen, Steve Enger, Arnljot Tveit.Quality of Life, Exercise Capacity and Comorbidity in Old Patients with Permanent Atrial Fibrillation .JAFIB.2008 Dec;Volume 1 Issue(4): 202-208.

Background: The impact of atrial fibrillation (AF) on quality of life (QoL) differs with the AF population studied and is influenced by comorbidity. In hospital-based studies younger and highly symptomatic patients may be overrepresented. We performed an observational cross sectional study in two municipalities, comparing 75 year-old patients with and without permanent atrial fibrillation, with respect to health-related QoL and exercise capacity, with adjustment for the effects of confounders.
Methods: Maximal treadmill exercise testing provided peak oxygen uptake (VO2 peak). Health-related QoL was assessed by self-completed SF-36 questionnaires. The lowest quartile identified poor outcomes.
Results: 27 subjects with permanent AF and 71 subjects in sinus rhythm participated. AF patients had higher prevalence of compensated chronic heart failure (p < 0.001), valvular heart disease (p < 0.001), lower mean VO2 peak (22.7 ± 5.5 vs. 28.6 ± 6.3 ml/kg/min; p < 0.001), and more often poor VO2 peak; crude OR 5.3 (95%CI 1.8, 15.3), adjusted OR 7.5 (2.0, 28.3). Median Physical Component Summary score (with 25th and 75th percentile) was 41 (31, 51) in AF vs. 52 (45, 55) in controls (p < 0.001). Furthermore, the AF group had higher odds for poor physical QoL scores; crude OR 5.0 (1.8, 13.7), adjusted OR 4.3 (1.5, 12.4). Median Mental Component Summary score was 56 (42, 61) in the AF group vs. 57 (51, 60) in controls (p=0.565). The AF group had non-significantly increased odds for poor mental QoL scores; crude OR 2.3 (0.8, 6.2), adjusted OR 2.8 (1.0, 8.4).
Conclusion: Also after adjustment for confounders, older patients with permanent AF had higher odds for poor exercise capacity and poor physical QoL compared to subjects in sinus rhythm.


Leukocyte Atrial Fibrillation Filtration Study


Citation : Albert H. O-Yurvati, Steven Rodriguez, Glen Bell,Damon Kennedy, Robert T. Mallet.Leukocyte Atrial Fibrillation Filtration Study .JAFIB.2008 Dec;Volume 1 Issue(4): 194-201.

Abstract

Purpose: Atrial fibrillation remains the leading postoperative complication following cardiopulmonary bypass. A randomized trial was undertaken to evaluate the effectiveness of leukocyte filtration and aprotinin, applied separately and in combination, on the incidence of post-operative atrial fibrillation. A secondary component of the study was the impact of these adjunct interventions on post-surgical renal and neurological dysfunction.

Methods: A total of 1,220 patients undergoing primary isolated coronary artery bypass grafting were randomly assigned to one of four treatment groups. The control group (305 patients) received standard cardiopulmonary bypass with moderately hypothermic (34ÂșC) cardioplegic arrest. In the filtration group (310 patients) leukocyte reducing filters were incorporated into the bypass circuit. The aprotinin group (285 patients) received full Hammersmith dose aprotinin. The combination therapy group (320 patients) received both aprotinin and leukocyte filtration.

Results: The incidences of atrial fibrillation were 25% in the control group, 16% in the filtration group, 19% in the aprotinin group and 10% in the combination therapy group (P < style=""> Renal dysfunction was detected in 3% of the control group, 2% of the filtration group, 8% of the aprotinin group, and 5% of the combination group (P < style=""> Neurological dysfunction occurred in 2% of the control group, 2% of the filtration group, 1% of the aprotinin group, and 2% of the combination group (P = n.s.).

Conclusions: Combination therapy with aprotinin and leukocyte filtration markedly reduced atrial fibrillation post-cardiopulmonary bypass, and was more effective than the individual treatments. Aprotinin treatment increased the incidence of renal dysfunction, and the addition of leukocyte filtration partially mitigated this detrimental effect of aprotinin.


Tuesday, September 16, 2008

Patient Perspective :Left atrial image registration to guide catheter ablation of atrial fibrillation: In the eye of the technology

Citation : Osmar Antonio Centurion.Left atrial image registration to guide catheter ablation of atrial fibrillation: In the eye of the technology .JAFIB.2008 Sep;1(3): 190-193.


Your EP doctor uses state-of-the-art imaging techniques to evaluate and treat Atrial Fibrillation. The currently used imaging methods include Transthoracic echocardiography, Transesophageal echocardiography (or TEE), Intracardiac echocardiography (ICE), Magnetic resonance angiography, MRI and multidetector CT.

Using these techniques it would be feasible to identify any clots (thormbi) before any procedure. Before any ablation procedure it is important to understand the anatomy of the left atrium and pulmonary vein.

In this editorial comment Dr. Osmar Centurion from Division of Electrophysiology and Arrhythmia Cardiovascular Institute in Asuncion, Paraguay provides an overview of relevance of technology in use of imaging for Afib management.

Left atrial image registration to guide catheter ablation of atrial fibrillation: In the eye of the technology

Atrial fibrillation is a common arrhythmia, and its incidence rise sharply with age and with heart failure. Since the beginning of the new millennium, the debate on ectopic foci versus reentry as the mechanism underlying atrial fibrillation (AF) in humans has continuously evolved. The finding of ectopic beats proceeding from the pulmonary veins in the initiation of atrial fibrillation gave a different approach to the therapeutic management of this arrhythmia. Recently, the mechanism of AF is considered to be a spiral wave with a continuously changing pattern of the activation wavefront, that is, a random multiple reentry of independent wavelets wandering in the atria around arcs of refractory tissue or the accentuation of focal activity originating mainly from the pulmonary veins, the superior or inferior vena cava, the ligament of Marshall, or even the right atrium.

Patient Perspective : Physical Activity and Incidence of Atrial Fibrillation in Older Adults: The Cardiovascular Health Study

Suneet Mittal. Physical Activity and Incidence of Atrial Fibrillation in Older Adults: The Cardiovascular Health Study .JAFIB.2008 Sep;1(3): 185-186.


Dr. Mittal from The St. Luke's-Roosevelt Hospital Center,Columbia University College of Physicians & Surgeons,New York, NY reviews the recently published study showing the benefits of light to moderate exercise in significantly lowering AF incidence in older adults.

Physical Activity and Incidence of Atrial Fibrillation in Older Adults: The Cardiovascular Health Study

Retrospective case-control studies and case series of younger athletes and middle-aged adults have suggested an adverse association between physical activity and development of atrial fibrillation. However, these studies have evaluated subjects engaged in either vigorous exertion or endurance training. On the other hand, habitual physical activity might be expected through salutatory effects on blood pressure, vascular compliance, coronary disease, and heart failure to reduce the incidence of atrial fibrillation in the general population. The aim of this study was to assess the effect of habitual light to moderate physical activity on the incidence of atrial fibrillation among older adults.

Patient Perspective :Underutilization of Warfarin Therapy in Elderly Patients with Atrial Fibrillation – Fear or False Sense of Security!

Citation :Mazda Biria, Ahmad Batrash, James Vacek, Loren Berenbom, Dhanunjaya Lakkireddy.Underutilization of Warfarin Therapy in Elderly Patients with Atrial Fibrillation – Fear or False Sense of Security! .JAFIB.2008 Sep;1(3): 133-138.


Warfarin (also known under the brand names Coumadin, Jantoven, Marevan, and Waran) is an anticoagulant. It is named after the Wisconsin Alumni Research Foundation, which sponsored its development. Patients with Atrial Fibrillation (AF) have an increased risk of clots (or thrombi) due to irregular heart beat.

Dr. Batrash et al from Kansas City Veterans Affairs Medical Center, Kansas City report a retrospective study showing underutilization of warfarin in elderly patients with AF due to false sense of security about the paroxysmal nature of AF, lack of proper insight about stroke risk (CHADS (2)), and fear of bleeding.

Underutilization of Warfarin Therapy in Elderly Patients with Atrial Fibrillation – Fear or False Sense of Security!

Background: Under utilization of warfarin in elderly patients with atrial fibrillation (AF) has been recognized as a significant health care issue. This study examines the rate and reasons for warfarin underutilization in elderly patients with AF at the Kansas City Veterans Affairs Medical Center.

Methods: Retrospective study reviewing electronic medical records of all patients aged 65 and older with the diagnosis of atrial fibrillation. Patients on warfarin were excluded. Reasons for not using warfarin were extracted by reviewing the electronic medical record. Anticoagulation indications for these patients were determined based on the ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation.

Results:Warfarin was not used by 407 patients (25%) with known AF. Average age was 79+6.2 years. 60% of patients had persistent or permanent AF. Prevalence of risk factors for thromboembolism included hypertension (74%), heart failure or ejection fraction of <40%

Conclusions:Underutilization of warfarin in elderly patients with atrial fibrillation remains a common problem despite their high risk for thromboembolic events. A false sense of security about the paroxysmal nature of AF, lack of proper insight about stroke risk (CHADS (2)), and fear of bleeding are the most common reasons for non use of warfarin.

Patient Perspective :Echocardiographic Prediction of Symptomatic Atrial Fibrillation In Patients with Rheumatic Mitral Stenosis and Normal Sinus Rhyth

Citation : Fahriye Vatansever Agca, Ozan Kinay, Mustafa Karaca,Muge Ildizli Demirbas,Serdar Biceroglu,Baris Kilicarslan,Cem Nazli,A. Oktay Ergene.Echocardiographic Prediction of Symptomatic Atrial Fibrillation In Patients with Rheumatic Mitral Stenosis and Normal Sinus Rhythm. JAFIB .2008 Sep;1(3): 139-144.


Mitral stenosis is a valvular heart disease characterized by the narrowing of the orifice of the mitral valve of the heart.Rheumatic mitral stenosis (RMS) increases the risk of both atrial fibrillation (AF) and thromboembolism.

Dr. Karaca et al from Atakalp Heart Hospital Cardiology Department,Turkey report the benefit of echocardiography to predict symptomatic AF in a study on patients with mitral stenosis and normal sinus rhythm.


Echocardiographic Prediction of Symptomatic Atrial Fibrillation In Patients with Rheumatic Mitral Stenosis and Normal Sinus Rhythm

Objectives: Rheumatic mitral stenosis (RMS) increases the risk of both atrial fibrillation (AF) and thromboembolism. 
Methods: Patients with mitral stenosis and normal sinus rhythm were enrolled in the study prospectively.The present study was designed to study whether echocardiographic evaluation in patients with mitral stenosis and normal sinus rhythm could predict the occurrence of symptomatic AF . 
Results: Sixty-two patients (51 females) with mitral stenosis and normal sinus rhythm were included in the study. Seven patients (11.2%) developed symptomatic AF and the remaining 55 were free of AF during a followed-up of 22±5 months. The following echocardiographic parameters were significantly increased and predicted the development of AF: left atrial(LA) mediolateral diameter (5.5 ± 0.5 cm vs 4.7 ± 0.7 cm), right atrial mediolateral diameter (4,7 ± 1.0 cm vs 3.6 ± 1.3 cm), LA area in the apical two chamber view ( 31 ± 3.2 cm2 vs 25 ± 5.8 cm2), right atrial volume (52 ± 22 cm3 vs 34 ± 19 cm3), and interatrial conduction time (IACT) (132 ± 22 msec vs 115 ± 16 msec). 
Conclusions: This study revealed that echocardiography can be used to predict symptomatic AF in patients with RMS and sinus rhythm.

Patient Perspective : Atrial Septal Defect and Atrial Fibrillation

Citation : George E. Blake, Dhanunjaya Lakkireddy. Atrial Septal Defect and Atrial Fibrillation. JAFIB .2008 Sep;1(3):173-184.


Atrial septal defect (ASD) is a form of congenital heart defect that enables blood flow between the left and right atria via the interatrial septum. The interatrial septum is the tissue that divides the right and left atria. Without this septum, or if there is a defect in this septum, it is possible for blood to travel from the left side of the heart to the right side of the heart, or vice versa.

Atrial Fibrillation (AF) is a common complication of ASD, and Dr. Blake et al from University of Kansas, Kansas City, KS discuss the diagnosis and management of ASD and AF.

Atrial Septal Defect and Atrial Fibrillation

Atrial fibrillation (AF) is a common complication in patients with atrial septal defects (ASDs). The link between AF and ASD is fairly complex and entails modifications in electrophysiologic, contractile and structural properties, at the cellular and tissue level, of both atria, mainly due to chronic atrial stretch and dilation. Surgical repair or transcatheter closure of ASDs are equally effective in reducing mortality and symptoms but limited in preventing or curbing AF, unless combined with an arrhythmia-specific procedure. Transesophageal echocardiography (TEE) and intracardiac echocardiography (ICE) have improved the safety and success of the above procedures. Finally, clearer understanding of the pathophysiology of AF in patients with ASD (and CHF, in general) has led to target-specific advances in medical management.

Patient Perspective :Impact of Smoking on the Atrial Substrate Characteristics in Patients with Atrial Fibrillation

Citation : Ta-Chuan Tuan,Shih-Lin Chang, Shih-Ann Chen.Impact of Smoking on the Atrial Substrate Characteristics in Patients with Atrial Fibrillation .JAFIB.2008 Sep;1(3): 170-172.

Smoking has multiple adverse effects on health and is known to be linked to Atrial fibrillation. In a brief review Dr. Steven-Chen et al from Taipei Veterans General Hospital discuss the effects of smoking on the causation, progression and management of Atrial fibrillation.

Impact of Smoking on the Atrial Substrate Characteristics in Patients with Atrial Fibrillation

Cigarette smoking is a common health issue throughout the world. It can cause the development of various major diseases, such as chronic obstructive pulmonary disease (COPD), most cardiovascular diseases and many types of cancer. Thus, people with a tobacco habit can produce devastating health consequences for themselves. At present, there are about five million people that die annually, which can be attributed to cigarette smoking, and half of those deaths, which are mortalities from smoking, always occur in middle age. Therefore, how to reduce cigarette smoking remains the most important work to avoid the causes of health disabilities and premature death.

Patient Perspective :Sinus Node Dysfunction in Atrial Fibrillation: Cause or Effect?

Citation : Anna Kezerashvili,Andrew K. Krumerman, John D. Fisher. Sinus Node Dysfunction in Atrial Fibrillation: Cause or Effect? .JAFIB.2008 Sep;1(3): 161-169.

Sick sinus syndrome, also called Sinus node dysfunction (SSS), is a group of abnormal heart rhythms (arrhythmias) presumably caused by a malfunction of the sinus node, the heart's "natural" pacemaker. Bradycardia-tachycardia syndrome is a variant of sick sinus syndrome where atrial flutter and fibrillation alternate with prolonged periods of asystole.

SSS often coexists with Atrial Fibrillation, and in this extensive and interesting review Dr. Fisher et al., from Montefiore Medical Center and Albert Einstein College of Medicine explore the close interplay between the two conditions.

Sinus Node Dysfunction in Atrial Fibrillation: Cause or Effect?

Atrial fibrillation (AF) and sick sinus syndrome (SSS) are two conditions that frequently coexist. Despite a wealth of available knowledge, the link between these two entities is poorly understood. Whether AF is a harbinger of SSS or whether SSS predisposes to AF has been the subject of much debate. AF results in sinus node remodeling on a cellular and molecular basis that may promote SSS. However, not all patients with atrial fibrillation have SSS. Though “AF begets AF”, AF may also beget SSS; and SSS may also beget AF. Multiple studies have demonstrated that sinus node dysfunction may precede the onset of AF. This review will focus on alterations to sinus node structure and function, overdrive suppression, ion channel remodeling, and transient myocardial ischemia as possible mechanisms associated with AF induced SSS. In addition, we will review evidence suggesting that SSS, characterized by a combination of atrial extrasystoles, dispersion of excitability recovery and sinus node ischemia, may lead to AF. Additional factors common to both conditions such as aging and interstitial atrial fibrosis, may explain their coexistence. All this raises many therapeutic challenges associated with the interplay of AF and SSS.

Patient Perspective : GIANT Flutter Waves in ECG Lead V1: a Marker of Pulmonary Hypertension

Citation : James A. Reiffel. GIANT Flutter Waves in ECG Lead V1: a Marker of Pulmonary Hypertension .JAFIB.2008 Sep;1(3): 187-189.

Atrial Flutter is a common heart rhythm abnormality that may or may not be associated with problems cardiac anatomy. The current diagnosis methods with ECG do not offer direct information on the anatomical defect.

In the case report Dr. Reiffel from Section of Electrophysiology, Columbia University College of Physicians and Surgeons and The New York Presbyterian Hospital, NY reports the novel ECG pattern that may allow detection of patients with pulmonary hypertension and Atrial flutter.

Cardiac Image Registration

Long procedure time and somewhat suboptimal results hinder the widespread use of catheter ablation of complex arrhythmias such as atrial fibrillation (AF). Due to lack of contrast differentiation between the area of interest and surrounding structures in a moving organ like heart, there is a lack of proper intraprocedural guidance using current imaging techniques for ablation. Cardiac image registration is currently under investigation and is in clinical use for AF ablation. Cardiac image registration, which involves integration of two images in the context of left atrium (LA), is intermodal, with the acquired image and the real-time reference image residing in different image spaces, and involves optimization, where one image space is transformed into the other. Unlike rigid body registration, cardiac image registration is unique and challenging due to cardiac motion during the cardiac cycle and due to respiration. This review addresses the basic principles of the emerging technique of registration and the inherent limitations as they relate to cardiac imaging and registration.

GIANT Flutter Waves in ECG Lead V1: a Marker of Pulmonary Hypertension

Atrial flutter (AFl) may exist with or without underlying structural heart disease. Typical AFl presents as a “sawtooth” pattern on the ECG – with inverted flutter (F) waves in the inferior leads and upright F waves in V1. This morphology offers no direct clues as to the underlying cardiac disorder, if any. Occasionally we have encountered giant F waves, most prominently in lead V1, reaching 5 mv or more in height – sometimes exceeding the QRS voltage. The significance of this pattern has not been investigated and reported on. To determine if giant F waves in V1 provide any insight into the presence/type/absence of specific underlying cardiac pathology, the history of 6 consecutive patients with giant F waves was reviewed. Upon review, the only factor common to each patient was the presence of or history of pulmonary hypertension. Right ventricular dilation and/or dysfunction and right atrial enlargement with or without tricuspid insufficiency were present in each by echocardiography. Giant F waves appear to occur in the setting of right heart dysfunction in patients with a history of or the continued presence of pulmonary hypertension. Their detection should indicate the need for right heart evaluation.

Patient Perspective : Cardiac Image Registration

Citation : Jasbir Sra.Cardiac Image Registration .JAFIB.2008 Sep;1 (3): 145-160.

Your EP doctor uses state-of-the-art imaging techniques to evaluate and treat Atrial Fibrillation. The currently used imaging methods include Transthoracic echocardiography, Transesophageal echocardiography (or TEE), Intracardiac echocardiography (ICE), Magnetic resonance angiography, MRI and multidetector CT. 


Using these techniques it would be feasible to identify any clots (thormbi) before any procedure. Before any ablation procedure it is important to understand the anatomy of the left atrium and pulmonary vein. 

In this extensive review Dr. Jasbir Sra from Aurora Sinai/Aurora St. Luke's Medical Centers, University of Wisconsin School of Medicine and Public Health- Milwaukee Clinical Campus, Wisconsin discusses the advances in technology for use of imaging methods and comprehensive report on different clinical studies which have used imaging methods in patients with Atrial Fibrillation.

Tuesday, July 15, 2008

Design of an Outpatient Atrial Fibrillation Center of Excellence: Current Experience with the Delivery of Pre-Procedure and Post Procedure Care

The population of patients with atrial fibrillation (AF) continues to expand and emerges to be the most common arrhythmia we deal with.Referrals to centers performing catheter based ablation procedures for AF also continue to grow as catheter ablation becomes an increasingly accepted therapeutic approach.

In this article we will describe the infrastructure we have developed to manage our atrial fibrillation ablation population at the Richard and Annette Bloch Heart Rhythm Center at the University of Kansas Hospital.Our goal is to provide a “nuts and bolts” overview from the allied health professional perspective.For concise reviews of AF management we recommend the ACC/AHA/EFC 2006 guidelines and the HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation

Atrial Fibrillation and Heart Failure

Atrial fibrillation is common in heart failure patients and is associated with increased mortality.Pharmacologic trials have not shown any survival benefit for a rhythm control over a rate control strategy.It has been suggested that sinus rhythm is associated with a survival benefit, but that the risks of anti-arrhythmic drug treatment and poor efficacy offset the beneficial effect.Catheter ablation for atrial fibrillation can establish sinus rhythm without the risks of anti-arrhythmic drug therapy.Data from randomized trials demonstrating a survival benefit for patients undergoing an ablation procedure for atrial fibrillation are still lacking.

Ablation of the AV junction and permanent pacing remain a treatment alternative in otherwise refractory cases.Placement of a biventricular system may prevent or reduce negative consequences of chronic right ventricular pacing.Current objectives and options for treatment of atrial fibrillation in heart failure patients are reviewed.

Catheter ablation for atrial fibrillation in patients with obesity

Obesity is a risk factor for atrial fibrillation (AF) and common comorbid conditions such as hypertension, sleep apnea, and structural heart disease. This study was designed to determine whether catheter ablation of AF can be performed safely and effectively in obese and overweight patients compared with patients with normal body weight.

Is Empirical Four Pulmonary Vein Isolation Necessary for Focally Triggered Paroxysmal Atrial Fibrillation?

In this study the authors compared two different ablation strategies for the treatment of paroxysmal atrial fibrillation (AF): selective isolation of the pulmonary vein triggering AF (SePVI) versus empirical isolation of all the four pulmonary veins (EmPVI).

Skin Burn at the Site of Indifferent Electrode after Radiofrequency Catheter Ablation of AV Node for Atrial Fibrillation.

Radiofrequency Ablation of AV node with permanent pacemaker has been used to achieve rate control in persistent symptomatic atrial fibrillation. Although RF Ablation is safe, complications may occur in up to 3% of the procedures. A rare complication of 2nd degree skin burn at indifferent electrode site has been described here. This report highlights the rare but possible complication in patients undergoing such a procedure and help in preventing by taking appropriate measures.

Are Atrial-Selective Drugs Superior to Currently Available Antiarrhythmic Drugs Used in the Treatment of Atrial Fibrillation?

Current pharmacologic strategies for the management of atrial fibrillation (AF) include use of

1) sodium channel blockers, which are contraindicated in patients with coronary artery or tructural heart disease because of their potent effect to slow conduction in the ventricles,

2) potassium channel blockers, which predispose to acquired long QT and Torsade de Pointes arrhythmias because of their potent effect to prolong ventricular repolarization, and

3) mixed ion channel blockers such as amiodarone, which are associated with multi-organ toxicity.Accordingly, recent studies have focused on agents that selectively affect the atria but not the ventricles.

Several atrial-selective approaches have been proposed for the management of AF, including inhibition of the atrial-specific ultrarapid delayed rectified potassium current (IKur), acetylcholine-regulated inward rectifying potassium current (IK-ACh), or connexin-40 (Cx40).

All three are largely exclusive to atria.Recent studies have proposed that an atrial-selective depression of sodium channel-dependent parameters with agents such as ranolazine may be an alternative approach capable of effectively suppressing AF without increasing susceptibility to ventricular arrhythmias.

Clinical evidence for Cx40 modulation or IK-ACh inhibition are lacking at this time. The available data suggest that atrial-selective approaches involving a combination of INa, IKur, IKr, and, erhaps, Ito block may be more effective in the management of AF than pure IKur or INa block. The anti-AF efficacy of the atrial-selective/predominant agents appears to be similar to that of conventionally used anti-AF agents,with the major difference being that the latter are associated with ventricular arrhythmogenesis and extracardiac toxicity.

Trigger Versus Substrate Ablation for Atrial Fibrillation.

Elimination of triggers has become the hallmark of catheter ablation of atrial fibrillation (AF). In particular, much attention has been paid to the elimination of triggering impulses from the pulmonary veins via pulmonary vein ablation procedures. While this approach has a proven track record for paroxysmal AF, the efficacy in non-paroxysmal AF has been less convincing. Thus, attention has been paid to elimination of the substrate responsible for AF perpetuation, including complex fractionated electrograms, dominant frequency sites, and autonomic ganglionated
plexi. None of these targets has yet become mainstream, but they are all under active investigation. As our knowledge of these targets increases and clinical studies are performed, a more refined approach to AF ablation will surely emerge.

Pre-Procedural Imaging to Direct Catheter Ablation of Atrial Fibrillation: Anatomy and Ablation Strategy.

Successful catheter ablation of atrial
fibrillation (AF) requires a detailed understanding of left atrial anatomy in
order to maximize the safety and efficacy of the procedure. Common and rare variants of left atrial and
pulmonary venous anatomy have been described which can affect the optimal
ablation strategy for each individual patient. These variants include the presence of a right or left middle pulmonary
vein, a left or right common pulmonary vein, a common inferior pulmonary vein,
a right top pulmonary vein, and other rare forms of anomalous pulmonary venous
drainage. There are also important
patient-specific differences in pulmonary venous ridges and left atrial roof
morphology. Pre-procedural CT or MR
imaging can define these anatomic variants in exquisite detail and be used with
image-integration strategies to direct the ablation procedure. In this review, we describe common and
uncommon variants that can be identified by pre-procedural imaging, and suggest
ablation strategies tailored to these anatomic variants.

Atrial Fibrillation Ablation In Obesity , Size Matters

Both obesity and atrial fibrillation (AF) have a significant negative impact on morbidity and mortality. In recent times, these conditions have become growing public health problems, being described separately as emerging epidemics. Obesity is increasingly recognized as a risk factor for developing AF, with the risk escalating with increasing body mass index (BMI). In addition, this association is greater for long-standing and permanent AF, suggesting a possible role for obesity in the maintenance of AF as well.

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Review of "Long-term endurance sport practice increases the incidence of lone atrial fibrillation in men: a follow-up study"

Introduction

The study is aimed to determine the incidence of lone atrial fibrillation in males according to sport practice levels and to identify possible clinical markers that increase the risk of lone atrial fibrillation (LAF) among marathon runners.

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Review of "Antiarrhythmic Effect of Statin Therapy and Atrial Fibrillation : A Meta-Analysis of Randomized Controlled Trials"

Aim

The aim of this meta-analysis was to improve the evaluation of the possible antiarrhythmic effect of statins on atrial fibrillation (AF) incidence or recurrence.

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Success of Radiofrequency Catheter Ablation of Atrial Fibrillation: Does Obesity Influence the Outcomes?

Background: Catheter ablation of atrial fibrillation (AF) is an increasingly popular therapeutic option for symptomatic patients who have failed multiple antiarrhythmic medications. Patients of higher body mass index often fail direct current cardioversion. The role of body mass index (BMI) on the success of AF ablation is not well understood.


Methods: We prospectively studied 893 patients who underwent AF ablation at the Cleveland Clinic Foundation between 1999 and 2003. Patients were divided into four classes based on their BMI: Class I (≤ 25); Class II (25.1-30); Class III (30.1-35) and Class IV (>35). They were compared for baseline demographic and clinical characteristics. Any recurrence of AF after 3 months of ablation was considered as failure. All classes were followed for at least 12 months and rates of failure were compared.


Results: Based on their BMI, 25% of patients were assigned to class I, 37% in class II, 21% in class III and 16% in class IV. Patients of higher classification (class III or IV) were more likely to be male (p<0.001), diabetic (p<0.001), smokers (p=0.002), with coronary artery disease (=0.018), echocardiographic evidence of left atrial enlargement (p=0.015) and longstanding AF (p=0.007). We found a significant correlation between long-term (one-year) AF recurrence after catheter ablation and BMI classification with recurrence rates of 5.2% in class I, 7.5% in class II, 14.1% in class III and 8.4% in class IV (p=0.01). The short-term recurrence rates of 12.7% in class I, 19.1% in class II, 23.0% in class III and 17.4% in class IV did not achieve statistical significance (p=0.05) .

Conclusion: Obesity is significantly associated with long-term AF recurrence after catheter ablation. Higher incidence of systemic inflammation, smoking & left atrial enlargement possibly contribute to higher failure rates in this sub-group of patients.

Characterization of Left Atrial Tachyarrhythmias in Patients Following Atrial Fibrillation Ablation: Correlation of surface ECG with Intracardiac Mapping

Catheter based ablation has become a popular treatment strategy in the management of patients with atrial fibrillation (AF). Although patients undergoing AF ablation can expect success rates in excess of 80%, 1-3 the procedure is associated with a small risk of complications, the commonest of which is the development of organized atrial tachyarrhythmias i.e., atrial tachycardias (AT) and / or flutters.4 The latter includes both typical (isthmus dependent) and atypical (usually left atrial) flutter circuits. Common to all of these tachycardias is the presence of well defined, regularly occurring “P” waves which may help with localization as well as provide insights into arrhythmia mechanism(s). Ultimately this information has implications for successfully mapping and ablating the tachycardia. The purpose of this paper is to provide the readers with a concise overview on the various organized atrial tachyarrhythmias seen post AF ablation and discuss their ECG manifestations vis-Ă -vis information obtained from intracardiac mapping / ablation.

Preparing The Electrophysiology Lab to Treat Atrial Fibrillation

In the past few years every lab has been looking for new procedures to perform. The latest procedure is Atrial Fibrillation due to the number of patients which has this arrhythmia. Besides just ordering the catheters needed for treatment of atrial fibrillation, the equipment in the electrophysiology lab is another important aspect of performing this procedure safely and efficiently.

Rate versus Rhythm Control Pharmacotherapy for Atrial Fibrillation: Where are We in 2008?

Atrial fibrillation (AF) is the most common sustained cardiac rhythm disturbance encountered by physicians. The management of AF is focused on control of heart rate, correction of rhythm disturbance, and risk-determined prophylaxis of thromboembolism. The goals of AF therapy are, as with other serious disorders, to reduce mortality (if possible) and mortality (improve quality of life, [QOL]). To this end, several large studies have examined rhythm-control versus rate-control strategies. Although a survival advantage to using rhythm control with currently available antiarrhythmic drugs has not been proven, neither has there been a significant excess risk versus rate control. Therefore, using our current therapies, the results have not supported rate control or rhythm control as being a preferable first-line therapy for AF as regards survival; importantly, neither do they disprove the hypothesis that maintenance of sinus rhythm is preferable to the continuation of AF, particularly if rate control fails to restore adequate QOL. Many post-hoc analyses and substudies have assessed QOL, functional status, and exercise tolerance, with the majority demonstrating important benefits associated with achievement of rhythm control. This review examines rate and rhythm control options, the clinical outcomes of several important AF trials, discusses the limitations in applying the major morbidity/mortality findings to everyday clinical practice, and summarizes the lessons learned.

Surgical Treatment of Atrial Fibrillation.

Atrial fibrillation (AF) is now commonly treated
at the time of valvular heart surgery or coronary artery bypass grafting. Surgical
ablation of AF, which is predicated upon the Maze procedure, includes creation
of lines of conduction block and excision of the left atrial appendage. A full bi-atrial lesion set is associated
with success in 80% to 95% of patients and virtually eliminates the risk of
late stroke. A complex but safe
operation, the classic cut-and-sew Maze procedure has been applied by
relatively few surgeons. However, recent
advances in understanding of the pathogenesis of AF and development of new
ablation technologies enable surgeons to perform pulmonary vein isolation,
create linear left and right atrial lesions, and remove the left atrial
appendage rapidly and safely. Lesions
are created under direct vision, minimizing the risk of damage to the pulmonary
veins and adjacent mediastinal structures. Recently developed instrumentation now enables thoracoscopic and keyhole
approaches, facilitating extension of epicardial AF ablation and excision of
the left atrial appendage to patients with isolated AF and no other indication
for cardiac surgery. In addition, novel
devices designed specifically for minimally invasive epicardial exclusion of
the left atrial appendage will broaden the range of treatment options for
patients with AF, possibly eliminating the need for anticoagulation in selected
patients.

Evaluation of Atrial Fibrillation



Identification of Atrial
Fibrillation



Atrial fibrillation (AF) is a supraventricular tachyarrhythmia
characterized by uncoordinated atrial activation. On the ECG fibrillatory (f)
waves (rapid oscillations with variable amplitude, shape and timing) replace
normal P waves. Ventricular response becomes irregular and rapid depending of
the intrinsic electrophysiological properties of the AV node
1 and the balance between vagal and sympathetic
tone
1.



The presence of an irregularly pulse is a clinical sign that can be
quickly and reliably identified in any healthcare situation and, indicates AF with
a high sensitivity and specificity (95% and 75%, respectively). If the
irregularity last for more than 20 seconds the specificity reaches 98%
2-4. Identification of AF can be done by using
manual pulse palpation in those presenting with a variety of symptoms. It is
desirable to check the blood pressure and pulse in all patients who present
with breathlessness, dyspnea, palpitations, syncope, dizziness or chest
discomfort. Furthermore, many patients presenting with an acute stroke are
found to be in AF albeit asymptomatic with respect to non-neurologic
complaints.



The finding of a sustained irregular wide QRS complex tachycardia may be
suspicious of AF conducted with bundle brunch aberrancy or over an accessory pathway,
and in patients with A-V sequential pacemakers can reflect an inadequate
configuration with ventricular tracking of sensed atrial activity.