Tuesday, May 24, 2016

EHRA(European Heart Rhythm Association) EP-Wires Surveys: What Is Common Practice In Device Management?

Citation: Carina Blomström-Lundqvist, Maria G Bongiorni

Guidelines and recommendations within the field of electrophysiological (EP) practice are usually drawn from the results of multicentre trials, often conducted in selected centers and under special circumstances. In contrast, daily practice is generally influenced by many factors, which may be different from those that are considered in strictly controlled scientific conditions. Even though patient registries may mirror daily practice, the enrollment of consecutive patients for longer periods of time for such purpose within the health care community is costly and time consuming. A short form of survey directed to physicians, could within a reasonable time frame highlight areas where the evidence base for clinical practice and implementation of guidelines needs to be augmented. Such short form of surveys, called EP Wires, are on-line surveys carefully constructed to give a picture of daily cardiac EP practice in Europe without burdening the responders with extensive data collection. The network of centers formed, are contacted on a regular basis every month. It is the purpose of this summary to present the result of four such EP wires, all of which concern devices, with special emphasis on centre differences and adherence to guidelines.

How To Better Identify Patients That Do Not Benefit From Prophylactic ICD Therapy?

Citation: Ian Mann MBBS MRCP, Amit Kaura MBChB, Paul A Scott DM MRCP

The implantable cardioverter defibrillator (ICD) has been demonstrated to improve survival by reducing sudden cardiac death (SCD) in patients with a low left ventricular ejection fraction (LVEF). Randomised trial data suggest that this mortality reduction is not constant among those implanted with a device, and has raised the significance of non-sudden cardiac death (non-SCD) as an important mode of death predicting limited benefit from ICD therapy. In this review article we explore the role of non-SCD and the risk prediction models that may aid identification of low LVEF patients unlikely to gain significant benefit from ICD therapy.

Non-Inducibility Or Termination As Endpoints Of Atrial Fibrillation Ablation: What Is Their Role?

Citation: Matthew Baker, MD, Prabhat Kumar, MBBS, James P. Hummel, MD, Anil K. Gehi, MD, FHRS

Catheter ablation is widely used to treat drug-refractory, symptomatic atrial fibrillation (AF). However, beyond pulmonary vein isolation, there remains little consensus on the recommended approach to ablation both in paroxysmal or persistent AF patients. Although ancillary ablation strategies are often used, the lack of a clear endpoint for AF ablation makes it challenging to evaluate their importance. Non-inducibility and termination of AF during AF ablation have been advocated as potential endpoints. Several studies have attempted to assess their role in an AF ablation protocol. However, the data for non-inducibility and termination as endpoints are mixed. Moreover, there are a number of limitations in the studies reported and limitations of the endpoints themselves. It is likely that non-inducibility or termination of AF during AF ablation may be markers of less structural remodeling rather than true endpoints for ablation. Herein, we review the relevant literature on the topic of inducibility and termination with respect to AF ablation and attempt to draw conclusions with guidance to further investigation.

Experimental Evidence Of The Role Of Renal Sympathetic Denervation For Treating Atrial Fibrillation

Citation: Dominik Linz, Christian Ukena, Milan Wolf, Benedikt Linz, Felix Mahfoud, Michael Böhm

Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant morbidity and mortality. In addition to mechanisms such as atrial stretch and atrial remodeling, also the activity of the autonomic nervous system has been suggested to contribute to the progression from paroxysmal to persistent AF. Catheter-based renal denervation (RDN) was introduced as a minimally invasive approach to reduce renal and whole body sympathetic activation which may result in atrial antiarrhythmic effects under some pathophysiological conditions. This review focuses on the potential effects of RDN on different arrhythmogenic mechanisms in the atrium and discusses potential anti-remodeling effects in hypertension, heart failure, and sleep apnea.

Indications For AF Ablation: Before Or After The Failure Of Antiarrhythmic Drug Therapy?

Citation: Akira Kimata, MD, Yoko Ito, MD, Kentaro Yoshida, MD

Catheter ablation of atrial fibrillation (AF) is considered to be better than anti-arrhythmic drug therapy in terms of maintaining sinus rhythm, and therefore, it has rapidly evolved to become a commonly performed procedure in major hospitals throughout the world. However, on the basis of the evidence currently available, we support the current guidelines recommending antiarrhythmic drugs as a first-line treatment in most patients with AF except younger patients with symptomatic paroxysmal AF with no evidence of structural heart disease, given the risk of fatal complications associated with the ablation procedure. We would like to emphasize that center volume and individual procedure experience are significant determinants of procedure-related complications. As another effect of AF ablation, preventing atrial remodeling and progression to persistent AF is also noteworthy. Further long-term data is needed to answer the question of whether ablation can prevent or delay the advance of structural remodeling and improve life prognosis, particularly in younger patients.

Silent Atrial Fibrillation: A Critical Review

Citation: Alessandro Barbarossa, MD, Federico Guerra, MD, Alessandro Capucci, MD

Atrial fibrillation (AF) in the most common cardiac arrhythmia, and is associated with an increased risk of thromboembolic events. Silent AF is an asymptomatic form of AF incidentally diagnosed during a routine test or manifesting as an arrhythmia-related complication. Although recent trials have clearly demonstrated that patients with sub-clinical AF are at increased risk of stroke, the real incidence of this form of AF is still unknown. In fact, studies about silent AF had been performed only in specific subgroups of patients such as those with implantable cardiac devices, with recent cryptogenic stroke or transient ischemic attack, and recently undergoing AF ablation. Continuous ECG-monitoring in patients without implantable cardiac devices may improve silent AF detection but its cost-effectiveness actually is not well established in all kind of patients. Moreover, recent data have revealed that only a small number of these patients may have sub-clinical AF within the month prior to their stroke suggesting a lack of temporal relationship between the stroke and the AF episode.
This paper will review available data on different diagnostic tools for silent AF detection with a focus on their cost-effectiveness, analyzing the direct correlation between the arrhythmia and embolic events, and discussing areas of uncertainty where further research is required.

Non-Invasive ECG Mapping To Guide Catheter Ablation

Citation: Ashok J. Shah, MD, Han S. Lim, MBBS, PhD, Seigo Yamashita, MD, Stephan Zellerhoff, MD, Benjamin Berte, MD, Saagar Mahida, MBChB, Darren Hooks, MD, Nora Aljefairi, MD, Nicolas Derval, MD, Arnaud Denis, MD, Frederic Sacher, MD, Pierre Jais, MD, Remi Dubois, PhD, Meleze Hocini, MD, Michel Haissaguerre, MD

Since more than 100 years, 12-lead electrocardiography (ECG) is the standard-of-care tool, which involves measuring electrical potentials from limited sites on the body surface to diagnose cardiac disorder, its possible mechanism and the likely site of origin. Several decades of research has led to the development of a 252-lead-ECG and CT-scan based, three dimensional electro-imaging modality to non-invasively map abnormal cardiac rhythms including fibrillation. These maps provide guidance towards ablative therapy and thereby help advance the management of complex heart rhythm disorders. Here, we describe the clinical experience obtained using non-invasive technique in mapping the electrical disorder and guide the catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats) and ventricular pre-excitation (Wolff-Parkinson-White syndrome).

My Patient Taking A Novel Oral Anticoagulant Needs Surgery, Device Implantation, Or Ablation

Citation: Siva Krothapalli, MD, Prashant D Bhave MD

Atrial fibrillation (AF) is a highly prevalent chronic condition and a growing number of patients are on chronic anticoagulation therapy with novel oral anticoagulant (NOAC) agents: dabigatran, rivaroxaban, and apixaban. Many of these patients are expected to require invasive procedures. There is no clear consensus regarding the peri-procedural management of patients using NOACs, as to how to minimize both bleeding risk and thromboembolism risk. This review of the current available literature is designed to help formulate peri-procedural anticoagulation strategies for patients with AF taking NOACs who are being considered for catheter ablation, device implant, or other surgery.
To help frame the discussion, we offer 3 case vignettes that we will revisit to at the end of the review of the existing literature.
Case 1: A 62 year-old female with hypertension, diabetes, and symptomatic paroxysmal AF who is prescribed dabigatran for thromboembolism prevention. She has failed attempts at maintaining sinus rhythm with antiarrhythmic drugs. She is now being considered for catheter ablation of AF.
Case 2: A 76 year-old male with hypertension, diabetes, prior stroke, and ischemic cardiomyopathy who has persistent drug-refractory AF. He is maintained on chronic anticoagulation with dabigatran for thromboembolism prevention. He has an implantable cardioverter-defibrillator (ICD) which requires a generator change.
Case 3: A 58 year-old male with hypertension and paroxysmal AF who takes rivaroxaban for thromboembolic prophylaxis and is being considered for a knee replacement surgery.

A Challenging Case Of Ventricular Arrhythmia In A Patient With Myocarditis: ICD Yes/No After Ablation

Citation: Maria L Narducci, Teresa Rio, Francesco Perna, Domenico D’Amario, Biagio Merlino, Riccardo Marano, Gianluigi Bencardino, Frediano Inzani, Gemma Pelargonio, Filippo Crea

In patients with myocarditis, early diagnosis and appropriate therapy are mandatory, as well as close clinical follow-up with particular regard to progression of disease and ventricular arrhythmia recurrences. The management of ventricular arrhythmias should follow current guidelines for ICD implantation, but new therapeutic options could be evaluated in these patients, such as combined epicardial/endocardial ablation and external wearable defibrillator. Particularly, depressed left ventricular ejection fraction (LVEF) represents the only risk marker for sudden cardiac death currently used in myocarditis, although the use of a single risk factor has limited utility. On this regard, combined analysis of myocardial tissue structure by cardiac magnetic resonance (CMR) and endomyocardial biopsy, in association with resting cardiac systolic function, could improve predictive accuracy for Sudden Cardiac Death (SCD) in patients with myocarditis.

Left Atrial Diastolic Dysfunction And Pulmonary Venous Hypertension In Atrial Fibrillation: Clinical, Hemodynamic And Echocardiographic Characteristics

Citation: J. Thomas Heywood, MD, FACC, Srikanth Seethala, MD, Tariq Khan, MD, Allen Johnson MD, FACC, Michael Smith, MD, David Rubenson, MD, FACC, Eric Reynolds, RDCS

Background: Left ventricular diastolic dysfunction has been well described; diastolic abnormalities of the LA are less frequently recognized and poorly understood.
Objective: The purpose of this study was to investigate the clinical, hemodynamic and echocardiographic features of left atrial (LA) diastolic dysfunction.
Methods: Patients with atrial fibrillation (AF), severe LA enlargement, and pulmonary venous hypertension (PVH, Group 1) were compared to patients with pulmonary arterial hypertension (PAH), normal LA size and sinus rhythm (Group 2). All underwent right heart catheterization and transthoracic echo to evaluate hemodynamics and LA function. Mitral regurgitation was evaluated by transesophageal echocardiography. LA diastolic function was measured by comparing filling fraction, pulmonary venous flow and compliance.
Results: Right atrial, pulmonary artery systolic and mean pressures were similar. Mean wedge pressure were increased in Group 1, 20.8±2.6 versus 9.7±2.8 mm of Hg (p<0 .0001="" 0.39="" 11.4="" 111.5="" 1="" 2="" 6.8="" a="" abnormal="" and="" between="" br="" by="" compared="" compliance="" correlated="" correlation="" diastolic="" difference="" divided="" dysfunction="" e="" filling="" fraction="" group="" height="" hemodynamic="" in="" index="" la="" large="" m2="" mitral="" ml="" mmhg="" most="" negative="" of="" p="" r="0.907," ratio="" regurgitation.="" s="" significant="" striking="" strong="" strongly="" the="" there="" to="" transmitral="" v="" versus="" very="" was="" wave="" with="" without="">Conclusion: LA diastolic dysfunction is present in some patients with long standing AF and PVH. LA diastolic dysfunction, in addition to left ventricular diastolic dysfunction, may contribute to the syndrome of heart failure with preserved left ventricular systolic function.

Non-Invasive Estimation Of Left Atrial Dominant Frequency In Atrial Fibrillation From Different Electrode Sites: Insight From Body Surface Potential Mapping

Citation: Marjan Bojarnejad, James R Blake, John Bourke, Ewan Shepherd, Alan Murray, Philip Langley

The dominant driving sources of atrial fibrillation are often found in the left atrium, but the expression of left atrial activation on the body surface is poorly understood. Using body surface potential mapping and simultaneous invasive measurements of left atrial activation our aim was to describe the expression of the left atrial dominant fibrillation frequency across the body surface.
20 patients in atrial fibrillation were studied. The spatial distributions of the dominant atrial fibrillation frequency across anterior and posterior sites on the body surface were quantified. Their relationship with invasive left atrial dominant fibrillation frequency was assessed by linear regression analysis, and the coefficient of determination was calculated for each body surface site.
The correlation between intracardiac and body surface dominant frequency was significantly higher with posterior compared with anterior sites (coefficient of determination 67±8% vs 48±2%, p<0 .001="" 23.0="" 70.3="" 79.6="" a="" and="" body="" br="" closest="" coefficient="" comparison="" determination="" had="" in="" it="" largest="" lead="" of="" p="" posterior="" site.="" site="" surface="" the="" to="" v1="" v9="" was="" with="">Left atrial dominant fibrillation frequency was more closely represented at posterior body surface sites.

Beverages Of Daily Life: Impact Of Caffeine On Atrial Fibrillation

Citation: Anna Vittoria Mattioli MD PhD FACC FESC

In recent years, clinical and observational studies reported that caffeine consumption was associated with cardiac arrhythmias, affected heart rate variability, and subsequently increased cardiovascular risk. The analysis of these paper shows that data are controversial and strongly depends on methodology. Moderate intake of caffeine seems to have protective effects on arrhythmias, on contrary high intake of caffeine seems to be associated with increased risk of atrial fibrillation. There is a deep difference when we analysed intake of caffeine from coffee compared to other sources. In very recent time an increase in caffeinated beverages, namely energy drinks, has been reported in young people and several arrhythmic complications has been observed. A review of literature is presented.

New Technologies In Atrial Fibrillation Ablation

Citation: John Rickard MD, MPH, Saman Nazarian MD, PHD

Atrial fibrillation (AF) is a major public health issue worldwide, the incidence of which is likely to continue to rise. With the birth of pulmonary vein isolation(PVI), cardiac ablation has emerged as key strategy for the treatment of AF. PVI using traditional point by point radiofrequency ablation is time consuming and technically challenging. Refining patient selection for PVI also remains an important goal. New ablative strategies using catheter-based balloon technologies, such as cryothermy and laser-based systems, may simplify PVI. In addition, new MRI-based techniques offer the hope of refining patient selection prior to ablation. Lastly, FIRM mapping represents an entirely new approach to AF ablation via the targeting of mechanisms that perpetuate AF rather than simply targeting triggers alone.

Vasovagal Syncope As A Manifestation Of An Evolutionary Selected Trait

Citation: Paolo Alboni, Marco Alboni

Some observations suggest that typical (emotional or orthostatic) vasovagal syncope (VVS) is not a disease, but rather a manifestation of a non-pathological trait. We conducted an extensive bibliographic research on the vasovagal reactions in animals, including humans, in order to investigate the possible factors that may explain the origin and evolution of VVS. We found two processes which appear relevant for the investigation of VVS evolution: fear/threat bradycardia (alarm bradycardia) in animals, mainly during tonic immobility and vasovagal reflex during hemorrhagic shock (thoracic hypovolemia) both in animals and humans. The available data suggest that VVS in humans, alarm bradycardia in animals and the vasovagal reflex during hemorrhagic shock share the same physiological mechanisms and that is indicative of a common evolutionary root. However, during the vasovagal reflex loss of consciousness occurs in humans, but it is absent (or extremely rare) in animals. That can be explained as a by-product due to the erect position and the large brain evolved in our species. If the vasovagal reflex persisted for millions of years along the vertebrates evolutionary history, we can reasonably assume that it has a function and it is not harmful. It could be neutral or beneficial, but the available data suggest it is beneficial; likely, it evolved as an advantageous response to stressful and possibly dangerous heart conditions. Emotional or orthostatic vasovagal reflex is preceded by enhanced sympathetic activity, which is harmful and possibly dangerous. The transient inhibition of the sympathetic system, together with activation of the vagal tone, characterizes VVS. The consequent slowing of the heart rate induced by the vasovagal reflex may constitute a beneficial break of the cardiac pump, thereby reducing myocardial oxygen consumption.We suggest that typical VVS should be regarded as a selected response, which probably evolved in the ancient past as a defense mechanism of the organism within some ancestral group(s) of vertebrates.

Watchman Device: Left Atrial Appendage Closure For Stroke Prophylaxis In Atrial Fibrillation

Citation: Dr Manoj N Obeyesekere, MBBS, MRCP, FRACP, FHRS

A concerning proportion of patients with atrial fibrillation (AF) with indications for oral anticoagulation (OAC) discontinue OAC or are never prescribed OAC therapy and many AF patients with the highest risk for embolic events off OAC also have the greatest risk for hemorrhagic complications on OACs. Medium-term efficacy and safety data provide evidence that the WATCHMAN device, the most studied device and the only one with randomized and medium-term follow-up data, may be a viable alternative to chronic warfarin therapy in nonvalvular AF patients. In addition to presenting key data pertaining to LAA closure techniques including the WATCHMAN device, this review will discuss crucial WATCHMAN implantation technical points.

The Growing Culture Of A Minimally Fluoroscopic Approach In Electrophysiology Lab

Citation: Michela Casella, Eleonora Russo, Francesca Pizzamiglio, Sergio Conti, Ghaliah Al-Mohani, Daniele Colombo, Victor Casula, Yuri D’Alessandra, Viviana Biagioli, Corrado Carbucicchio, Stefania Riva, Gaetano Fassini, Massimo Moltrasio, Fabrizio Tundo, Martina Zucchetti, Benedetta Majocchi, Vittoria Marino, Giovanni Forleo, Pasquale Santangeli, Luigi Di Biase, Antonio Dello Russo, Andrea Natale, Claudio Tondo

Most of interventional procedures in cardiology are carried out under fluoroscopic imaging guidance. Besides other peri-interventional risks, radiation exposure should be considered for its stochastic (inducing malignancy) and deterministic effects on health (tissue reactions like erythema, hair loss and cataracts). In this article we analized the radiation risk from cardiovascular imaging to both patients and medical staff and discusses how customize the X-ray system and how to implement shielding measures in the cath lab. Finally, we reviewed the most recent developments and the latest findings in catheter navigation and 3D electronatomical mapping systems that may help to reduce patient and operator exposure.

Risks Related To Fluoroscopy Radiation Associated With Electrophysiology Procedures

Citation: Eugenio Picano, Emanuela Piccaluga, Renato Padovani, Claudio Antonio Traino, Maria Grazia Andreassi, Giulio Guagliumi

The benefits of cardiac imaging are immense, and modern cardiac electrophysiology (EP) requires the extensive and versatile use of a variety of cardiac imaging and radiology-based techniques. In the cardiac electrophysiology lab, doses can range around a reference effective dose (ED) of 15 milliSievert corresponding to 750 chest x-rays for a cardiac radiofrequency ablation, ranging from less than 2 to > 60 mSv. The reference dose for a regular pacemaker or ICD implant is 4 mSv (range 1.4-17) and for a CRT implant is 22 mSv (range 2.2-95). Doses on the order of magnitude of 10-100 milliSievert (mSv) correspond to a low (albeit definite, not negligible) additional lifetime risk of fatal and non-fatal cancer from between 1 in 1000 (10 mSv) to 1 in 100 (100 mSv). The increasing use and complexity of cardiac electrophysiology techniques have not been matched by increasing awareness and knowledge by prescribers and practitioners. The protection of doctors is just as important as protection of patients. Most experienced (and most exposed) interventional cardiologists and electrophysiologists have an exposure per annum of around 5 mSv, two to three times higher than diagnostic radiologists, with a typical cumulative lifetime attributable risk on the order of magnitude of 1 cancer (fatal and non-fatal) per 100 exposed subjects. Operator dose per procedure correlates somewhat with the patient dose, but may be typically 1000 times lower depending upon the shielding employed (one unit of incidence scatter dose for the operator when 1000 units of incident dose are given to the patient). However, adequate radiation protection training and diligent protection can reduce this radiation exposure by 90%.
The priority given to radioprotection in every cardiology department is an effective strategy for primary prevention of cancer, a strong indicator of the quality of the cardiology division, and the most effective shielding for enhancing the safety of patients, doctors, and staff.

Anatomic Challenges In Pediatric Catheter Ablation

Citation: Thomas A. Pilcher MD, Elizabeth V. Saarel MD

Pediatric patients present unique anatomic challenges for catheter ablation. Small patient size requires special adaptation and understanding to perform safe procedures when clinically indicated. The anatomic variations of congenital heart disease also create problems that require pre-procedural preparation for each case in addition to a specialized understanding of a vast anatomic variation and surgical repairs. This understanding coupled with the knowledge of the pathophysiology of arrhythmia disorders and the biophysics of catheter ablation technology are required to perform successful and safe ablation procedures in this special population.

Clinical Relevance Of Systematic CRT Device Optimization

Citation: Maurizio Lunati, Giovanni Magenta, Giuseppe Cattafi, Antonella Moreo, Giacomo Falaschi, Danilo Contardi, Emanuela Locati

Cardiac Resynchronization Therapy (CRT) is known as a highly effective therapy in advanced heart failure patients with cardiac dyssynchrony. However, still one third of patients do not respond (or sub-optimally respond) to CRT. Among the many contributors for the high rate of non-responders, the lack of procedures dedicated to CRT device settings optimization (parameters to regulate AV synchrony and VV synchrony) is known as one of the most frequent.
The most recent HF/CRT Guidelines do not recommend to carry-out optimization procedures in every CRT patient; they simply state those procedures “could be useful in selected patients”, even though their role in improving response has not been proven.
Echocardiography techniques still remain the gold-standard reference method to the purpose of CRT settings optimization. However, due to its severe limitations in the routine of CRT patients management (time and resource consuming, scarce reproducibility, inter and intra-operator dependency), echocardiography optimization is widely under-utilized in the real-world of CRT follow-up visits. As a consequence, device-based techniques have been developed to by-pass the need for repeated echo examinations to optimize CRT settings.
In this report the available device-based optimization techniques onboard on CRT devices are shortly reviewed, with a specific focus on clinical outcomes observed in trials comparing these methods vs. clinical practice or echo-guided optimization methods. Particular emphasis is dedicated to hemodynamic methods and automaticity of optimization algorithms (making real the concept of “ambulatory CRT optimization”). In fact a hemodynamic-based approach combined with a concept of frequent re-optimization has been associated - although retrospectively - with a better clinical outcome on the long-term follow-up of CRT patients. Large randomized trials are ongoing to prospectively clarify the impact of automatic optimization procedures.

ICD Therapy In RVOT-VT And Early Stage ARVD/C Patients

Citation: Yoshiyasu Aizawa MD, Seiji Takatsuki MD, Keiichi Fukuda MD

Implantable cardioverter-defibrillators (ICDs) improve the survival of patients with ischemic or non-ischemic cardiomyopathy and a reduced ejection fraction. However, the efficacy of ICD therapy in patients with right ventricular outflow tract ventricular tachycardia (RVOT-VT) and early stage arrhythmogenic right ventricular dysplasia / cardiomyopathy (ARVD/C) has not been well clarified. Although the prognosis of RVOT-VT is generally good, malignant forms of RVOT-VT resulting in polymorphic VT have been reported by several investigators. Radiofrequency catheter ablation is still effective in such patients, and thus an ICD implantation is usually not required. On the other hand, according to the current guidelines in patients with ARVD/C, an ICD implantation is recommended for secondary prevention when the patients develop sustained VT or VF. An ICD implantation may also be considered for primary prevention in high-risk patients: extensive disease, family history of sudden cardiac death, or undiagnosed syncope. Since an ICD implantation in the early stage of ARVD/C is controversial, physicians should well consider its risks and benefits. Early intervention with ICD therapy in ARVD/C patients may reduce the arrhythmic death rate but increases the device related complications especially in younger patients.

Control Of Hypertension Improves The Outcome Of Therapies For Paroxysmal And Persistent Atrial Fibrillation

Citation: Dr Chris Hayes

Hypertension is known to increase the risk of atrial fibrillation. It has a role to play in atrial fibrosis and remodeling which tends to propagate further atrial fibrillation. Current anti arrhythmic therapy is unsatisfactory due to its toxicity. Management of hypertension offers an attractive target for improving therapy of atrial fibrillation. We examine the current evidence for anti hypertensive therapy in atrial fibrillation.

Focal Impulse And Rotor Mapping (Firm): Conceptualizing And Treating Atrial Fibrillation

Citation: Junaid A. B. Zaman, MA, BM, BChir1, Amir Schricker, MD, Gautam G. Lalani, MD,Rishi Trikha, BS, David E. Krummen, MD, Sanjiv M. Narayan, MD, PhD

Current approaches for the ablation of atrial fibrillation are often effective, but only partially rooted in mechanistic understanding. Accordingly, they are unable to predict whether a given patient will or will not do well, or which lesions sets should or should not be performed – in any given patient. This goal would require clearer mechanistic definition of what sustains AF after it has been triggered (i.e. electrophysiological substrates). There are two schools of thought. The first proposes disorganized activity that self-sustains with no ‘driver’, and the second describes drivers that then cause disorganization. Interestingly, these mechanisms can be separated in human studies by mapping approach – proponents of the disorganized hypothesis studying small atrial areas at high resolution, and proponents of the driver model studying wide fields-of-view at varying resolutions. Focal impulse and rotor modulation (FIRM) mapping combines a wide field of view with physiologically based signal filtering and phase analysis, and has revealed that human AF is often sustained by rotors. In the CONFIRM Trial, targeting stable AF rotors/sources for ablation improved the single-procedure efficacy for paroxysmal and persistent AF over conventional ablation alone, as now confirmed by independent laboratories. FIRM mapping gives a mechanistic foundation to predict whether any selected lesions should intersect AF sources in any given patient and which mechanisms may cause recurrence. Rotors of varying characteristics have now been shown by many groups. These insights have reinvigorated interest in AF mapping, and rationalizing these findings will likely translate into improved therapy for our patients.

Management Of Atrial Fibrillation In Patients With Heart Failure

Citation: Andrew E. Darby, MD

Atrial fibrillation (AF) and heart failure (HF) are common conditions that frequently coexist. Both conditions share risk factors, are associated with increased morbidity and mortality, and may worsen the other. The presence of heart failure and symptoms associated with it may influence both the approach to management (i.e., rate versus rhythm control) and the treatment options available for AF patients. The presence of HF increases the stroke risk with atrial fibrillation, and thromboembolic risk reduction is paramount. Some patients with HF tolerate AF poorly and therefore , a rhythm control strategy may be preferred. More insight into the success rates with catheter ablation in heart failure has been gleaned from recent studies.

One-Shot Ablation For PV Isolation

Citation: Miguel Nobre Menezes, Nuno Cortez-Dias, Luís Carpinteiro, João de Sousa

Atrial fibrillation ablation has evolved considerably over the last few years. In this article we review current and past catheter ablation techniques, with a special focus on new simplified systems that allow a faster and simpler procedure, so called “one-shot” atrial fibrillation ablation.

New Insights On Ablation Of Persistent Atrial Fibrillation: Evidence From The SARA Trial

Citation: Felipe Bisbal MD, Lluís Mont MD PhD

Since Haissaguerre et al first described the pathogenic role of pulmonary vein firing as a crucial mechanism triggering atrial fibrillation, catheter ablation has been recommended as a curative treatment. Several trials have demonstrated that ablation is an effective treatment in most patients with paroxysmal atrial fibrillation and low-grade remodelled atria. In patients with persistent AF, there is substantially less evidence, mostly based on non-randomized studies, supporting this recommendation. The available scientific evidence as well as the current approaches to treating persistent AF patients are discussed in this article. Further, we describe the main findings of the SARA trial and put them into perspective.

Catheter Ablation Of Atrial Fibrillation In The Elderly: Risk Benefit Analysis

Citation: Samet Yılmaz, M.D,Ugur Canpolat, M.D

Over the past decade, catheter ablation has emerged as an important therapeutic option and reserved for drug refractory symptomatic paroxysmal and persistent atrial fibrillation (AF). Although elderly population constitutes the significant amount of AF patients, literature data is inadequate regarding the use of catheter ablation for elderly AF patients. Since there has been significant improvement in efficacy and safety of the AF ablation in last decade, it has become widespread accross the whole world. As the life expectancy continues to grow in population and outcomes of catheter ablation for AF further improve, higher number of elderly patients are likely to undergo catheter ablation for AF. Therefore, in this paper we reviewed the published literature to date regarding the clinical efficacy and safety of catheter ablation for AF in elderly patients.

Improvements In Af Ablation Outcome Will Be Based More On Technological Advancement Versus Mechanistic Understanding

Citation: Chen-yang Jiang, MD, Ru-hong Jiang, MS

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. Catheter ablation has proven more effective than antiarrhythmic drugs in preventing clinical recurrence of AF, however long-term outcome remains unsatisfactory. Ablation strategies have evolved based on progress in mechanistic understanding, and technologies have advanced continuously. This article reviews current mechanistic concepts and technological advancements in AF treatment, and summarizes their impact on improvement of AF ablation outcome.

A Difficult Case Of Left Atrial Flutter

Citation: Reinder Evertz MD, Juan Acosta MD, David Andreu M.Sc, Josep Brugada MD, PhD, Lluis Mont MD, PhD

A 55-year-old male was referred for a third ablation procedure because of recurrent atrial fibrillation. During re-isolation of the inferior right pulmonary vein the patient developed an atypical flutter with an clockwise activation pattern around the mitral annulus. Linear ablation at the left mitral isthmus transformed but did not terminate the tachycardia. The cavotricuspid isthmus proved to be a second critical isthmus and linear ablation at this site terminated the tachycardia.

Atrial Fibrillation Radiofrequency Ablation: Safety Using Contact Force Catheter In A Low-Volume Centre

Citation: Diego Vaccari, MD, Daniele Giacopelli, MSc, Eros Rocchetto, MSc, Sabina Vittadello, MD, Roberto Mantovan

The tip-to-tissue contact force (CF) has been identified as a potential determinant of lesion quality during radiofrequency (RF) ablation. The aim of this paper is to report the experience of a single low-volume centre in the atrial fibrillation (AF) ablation procedure with an RF catheter capable of measuring this parameter. CF data and their possible implications on patient safety are presented.
Thirty-nine consecutive patients suffering of paroxysmal or permanent AF received percutaneous ablation with the novel catheter studied. Procedural characteristics, CF applied and safety events related to the procedure were reported.
During RF application the mean CF value was 17 ± 3 g, with a maximum mean value of 37 ± 8 g. CF value never exceeded 62 g and in the 74% of the RF applications ranged between 10 g and 30 g. No complication related to the catheter manipulation or to the energy delivered was observed.
This study of a single centre with a low level of experience in AF ablation suggests that the ability to measure CF may provide additional useful information to the operator. It ensures uniform ablations, with little variability in the catheter manipulations, and it avoids excessive contact forces increasing the patient safety.

Retrospective Evaluation Of Novel Percutaneous Left Atrial Appendage Ligation Using The Lariat Suturing Device: Single Center Initial Experience

Citation: Soidjon Khodjaev MD, Duong Le, MD, MSc, Wei Rao MD, Remo Morelli MD, FACC

Background: The left atrial appendage (LAA) is the source of considerable thromboemboli responsible for embolic strokes in patients with atrial fibrillation (AF). The LARIAT™ suturing device has been used to ligate the LAA and negate the use of systemic anticoagulation. However, its efficacy and stroke outcome is still unknown.

Methods: We retrospectively evaluated the clinical status and risk of occurrence of systemic emobolic events, strokes, transient ischemic attacks, and procedure related complications in patients after LAA ligation using the LARIAT™ device.

Results: Permanent suture was successfully delivered in 21 patients. Mean follow up time was 17.2+-3.3 months. The average HAS-BLED score was 3.3+/-1.1. Only 1 patient developed clinical symptoms of stroke 7 days post procedure. One patient had uncomplicated perioperative bleeding not requiring blood transfusion. One patient developed transient ECG changes of ischemia during mapping for ablation following the LAA ligation and subsequently, underwent bypass surgery. Three patient developed post-procedural pericarditis and were medically managed. Three patients died from non-LAA ligation related conditions including congestive heart failure, lung cancer, and severe coronary disease. We observed a 32% and 30% reduction in the annual risk of stroke when compared to the expected risk of stroke based on the CHADS2 and CHA2DS2-VASc score respectively.

Conclusion: LAA ligation using the LARIAT™ suturing device is clinically feasible in carefully selected patients. This study has the longest follow up period to date, however further studies are required to determine the efficacy of stroke reduction and long-term clinical outcomes.

World Atrial Fibrillation Awareness Day – High Time To Spread The Word

Citation: Dhanunjaya Lakkireddy MD, FACC, FHRS, Andrea Natale MD, FACC, FECS, FHRS

Welcome back to the September issue of JAFIB. We are sure you are back to the grind from your summer vacations. September is the Atrial Fibrillation Awareness month. Heart Rhythm Society has officially launched a bigger campaign in promoting awareness of the disease across the world. The Global Atrial Fibrillation Alliance Foundation (www.global-af-alliance.org ) continues its work on this patient-physician-industry partnership in multiple cities across the world. The second Saturday of every September has been commemorated as the World AF Awareness Day. This year it was commemorated on the 13th of September. Several cities have a wide range of activities including AF walk, run, yoga and town hall meetings on this day to spread the word on prevention and early recognition and treatment. We will have a full report of this exciting global event in our next issue. Notably the Governors of the states of Kansas and Arkansas have issued proclamations recognizing the efforts of Global AF Alliance for its unfettered awareness campaign and officially pronouncing every second Saturday of September as the World AF Awareness Day here forth. There were 5K and 10K Runs and Walks with awareness material distributed.

Monday, May 23, 2016

Preserving Cognitive Function in Patients with Atrial Fibrillation

Citation: Tina Lin MD, Erik Wissner MD, Roland Tilz MD, Andreas Rillig MD, Shibu Mathew MD, Peter Rausch MD, Christine Lemes MD, Sebastian Deiss MD, Masashi Kamioka MD, Tudor Bucur MD, Feifan Ouyang MD, Karl-Heinz Kuck MD, Andreas Metzner MD

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and is associated with significant morbidity and mortality. Its prevalence increases with increasing age, and is one of the leading causes of thromboembolism, including ischemic stroke. The prevalence of cognitive dysfunction also increases with increasing age. Although several studies have shown a strong correlation between AF and cognitive dysfunction in patients with and without overt stroke, a direct causative link has yet to be established. Rhythm vs rate control and anticoagulation regimens have been extensively investigated, particularly with the introduction of the novel anticoagulants. With catheter ablation becoming more prevalent for the management of AF and the ongoing development of various new energy sources and catheters, an additional thromboembolism risk is introduced. As cognitive dysfunction decreases the patient’s ability to self-care and manage a complex disease such as AF, this increases the burden to our healthcare system. Therefore as the prevalence of AF increases in the general population, it becomes more imperative that we strive to optimize our methods to preserve cognitive function. This review gives an overview of the current evidence behind the association of AF with cognitive dysfunction, and discusses the most up-to-date medical and procedural treatment strategies available for decreasing thromboembolism associated with AF and its treatment, which may lead to preserving cognitive function.

Selective Versus Total Pulmonary Vein Isolation In Atrial Fibrillation Ablation

Citation: Sonia Ammar, MD, Tilko Reents, MD, Stephanie Fichtner, MD1, Gabriele Hessling, MD, Isabel Deisenhofer, MD

One of the great discoveries in cardiac electrophysiology was the recognition of the crucial role of pulmonary vein (PV) myocardial sleeves for the initiation of atrial fibrillation (AF). Based on this concept, catheter ablation aiming at electrical isolation of all pulmonary veins has become the routine approach for of paroxysmal AF. Another concept implies selective isolation only of arrhythmogenic PVs. Based on the most important studies dealing with both approaches, we describe pros and cons of selective compared to complete pulmonary vein isolation (PVI) and illustrate why selective PVI has not found widespread acceptance in the electrophysiologic community.

Atrial Fibrillation After Robotic Cardiac Surgery

Citation: Leonardo Canale, Cleveland Clinic,Stephanie Mick, Cleveland Clinic, Ravi Nair, Cleveland Clinic Abu Dhabi, Tomislav Mihaljevic, Cleveland Clinic Abu Dhabi, Johannes Bonatti, Cleveland Clinic Abu Dhabi

Atrial fibrillation is one of the commonest complications after cardiac surgery and it is associated with considerable morbidity and increase in mortality. Recently, robotic approach to many heart operations has become feasible and reproducible. We here investigate and review the incidence of atrial fibrillation after robotic cardiac surgery. We found that its incidence is overall low and less than in conventional heart surgery.

Treatment Or Cure Of Right Ventricular Outflow Tract Tachycardia

Citation: Abdel J. Fuenmayor MD

Right ventricular outflow tract (RVOT) ventricular tachycardias (VT) occur in the absence of structural heart disease and are called idiopathic ventricular arrhythmias. These arrhythmias are thought to be produced by adenosine-sensitive, cyclic AMP mediated, triggered activity and are commonly observed in adolescents and young adults. In the ECG, they appear with a wide QRS complex, a left bundle branch block morphology and, usually, an inferior QRS axis. In the last few years, there has been an increasing number of reports suggesting the possibility of a curative treatment of RVOT VT by means of catheter ablation. This paper reviews the rate of cure of such arrhythmias by discussing the effects of catheter ablation on symptoms, arrhythmia detection, possibility of induction, and short- and long-term follow-up studies.

Techniques To Improve Left Atrial Appendage Imaging

Citation: Sahar S. Abdelmoneim, M.B.B.C.h., M.Sc, MS, FESC, Sharon L. Mulvagh, MD, FASE, FACC

The clinical importance of the left atrial appendage (LAA) is increasingly recognized. The assessment of the unique anatomy and function of the LAA is especially important in the setting of atrial fibrillation (AF). AF is the most commonly occurring cardiac arrhythmia, and the association of LAA thrombi and AF has been well established. Transesophageal echocardiography (TEE) is a widely available imaging tool to exclude the potential presence of LAA thrombus prior to cardioversion in patients with AF. Commercially available products containing microbubbles to enhance ultrasound images, termed "ultrasound contrast agents" (UCA) are indicated for use with transthoracic echocardiography to improve cardiac structure and function assessment, but can also be used with TEE as an adjunctive tool to assess the LAA. Integrative multimodality imaging techniques can be used in evaluation of the LAA as indicated in various clinical scenarios including: stroke risk assessment, decision-making prior to cardioversion in AF, placement and assessment percutaneous transcatheter LAA occlusion procedures, and assessment of results of procedural or surgical exclusion of LAA. In this article, various imaging techniques that are available for non-invasive visualization of the LAA will be reviewed along with the clinical importance of assessment of LAA anatomy and function.

The Role Of Contact Force In Atrial Fibrillation Ablation

Citation: Hiroshi Nakagawa, MD, PhD, and Warren M. Jackman, MD

During radiofrequency (RF) ablation, low electrode-tissue contact force (CF) is associated with ineffective RF lesion formation, whereas excessive CF may increase the risk of steam pop and perforation. Recently, ablation catheters using two technologies have been developed to measure real-time catheter-tissue CF. One catheter uses three optical fibers to measure microdeformation of a deformable body in the catheter tip. The other catheter uses a small spring connecting the ablation tip electrode to the catheter shaft with a magnetic transmitter and sensors to measure microdeflection of the spring.
Pre-clinical experimental studies have shown that 1) at constant RF power and application time, RF lesion size significantly increases with increasing CF; 2) the incidence of steam pop and thrombus also increase with increasing CF; 3) modulating RF power based on CF (i.e, high RF power at low CF and lower RF power at high CF) results in a similar and predictable RF lesion size.

In clinical studies in patients undergoing pulmonary vein (PV) isolation, CF during mapping in the left atrium and PVs showed a wide range of CF and transient high CF. The most common high CF site was located at the anterior/rightward left atrial roof, directly beneath the ascending aorta. There was a poor relationship between CF and previously used surrogate parameters for CF (unipolar or bipolar atrial potential amplitude and impedance). Patients who underwent PV isolation with an average CF of <10 ablation="" af="" an="" average="" cf="" experienced="" g="" higher="" of="" patients="" recurrence="" using="" whereas="" with=""> 20g had lower AF recurrence. AF recurred within 12 months in 6 of 8 patients (75%) who had a mean Force-Time Integral (FTI, area under the curve for contact force vs. time) < 500 gs. In contrast, AF recurred in only 4 of 13 patients (21%) with ablation using a mean FTI >1000 gs. In another study, controlling RF power based on CF prevented steam pop and impedance rise without loss of lesion effectiveness.

These studies confirm that CF is a major determinant of RF lesion size and future systems combining CF, RF power and application time may provide real-time assessment of lesion formation.

Superior Vena Cava Isolation In Ablation Of Atrial Fibrillation

Citation: Koji Higuchi, Yasuteru Yamauchi, Kenzo Hirao

Superior vena cava (SVC) is one of the most important non-pulmonary vein (PV) origins of atrial fibrillation (AF). SVC isolation (SVCI) is effective especially in patients with paroxysmal AF from SVC origin. It should be carefully performed because of potential complications such as phrenic nerve paralysis, SVC stenosis, and sinus node injury. There are two major different approaches to treat SVC focus in the ablation of AF. The conventional approach is to perform SVCI only if AF from the SVC origin is actually recognized using pacing maneuvers and/or isoproterenol infusions. Another approach is the empiric SVCI in addition to PV isolation in all cases. The rate of AF freedom one year after initial AF ablation by empiric SVCI was almost same as the conventional method (85-90% AF freedom). Additionally, the conventional method has also a good result even 5 years after ablation (73.3% AF freedom). Because of the excellent result in the conventional approach and possible complications after the SVCI, the empiric SVCI + PVI in all AF cases is still controversial . Patients with a long SVC myocardial sleeve are possible candidates for empiric SVCI in addition to PVI.

Complications From Left Atrial Appendage Exclusion Devices

Citation: Laura Perrotta, Stefano Bordignon, Daniela Dugo, Alexander Fürnkranz, Athanasios Konstantinou, Giuseppe Ricciardi, Paolo Pieragnoli, Boris Schmidt, KR Julian Chun

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and has been identified as an independent risk factor for stroke. Prevention of thromboembolic events has been based on oral anticoagulation (OAC) using Vitamin K antagonists (VKA). However, long-term OAC medication is limited by an increased bleeding risk and a low patient compliance. Relying on the observation that the majority of cardiac thrombi originate from the left atrial appendage (LAA) different devices aiming for LAA closure have been proposed. This review will discuss contemporary LAA closure devices with special emphasis on procedure related complications.

Management Of Pulmonary Vein Stenosis Following Catheter Ablation Of Atrial Fibrillation

Citation: Narendra Kumar, MD, Kevin Phan, BS, Ismail Aksoy, MD, Laurent Pison, MD, PhD, Carl Timmermans, MD,PhD, Jos Maessen, MD,PhD, Harry Crijns, MD,PhD

There is limited literature available regarding PV (pulmonary vein) stenosis management. Starting from its incidence, subsequent follow up using imaging technologies to monitor the success and the way of managing different groups pose varied opinions. However, with newer technological advancements and better understanding of mechanism of the atrial fibrillation ablation, the incidence of PV stenosis secondary to catheter ablation is declining. This paper highlights the current trends and future of management of PV stenosis secondary to catheter ablation for atrial fibrillation.

The Unique Mediguide Technology For CRT Lead Placement And Catheter Ablation

Citation: Carlo Pappone, MD, Martina Boscolo Berto, MD and Vincenzo Santinelli, MD

Electrophysiologic procedures such as catheter ablation and/or cardiac resynchronization therapy (CRT) are usually performed under fluoroscopic guidance alone. Currently, we are witnessing the birth of a new era in which many patients can be safely and effectively treated without the use of fluoroscopy. Using MediGuide technology continuous fluoroscopy is no longer required to ascertain the position of the device/catheter, which minimizes the radiation exposure for both the physician and patient, with a further benefit by minimal need for contrast agent. This novel system provides real time tracking of devices projected into live fluoroscopy or pre-recorded cine-angiography. MediGuide technology is an important step forward facilitating complex ablation procedures such as AF ablation and CRT implantation.

State Of The Art In Left Atrial Appendage Ligation - The Lariat

Citation: Pramod Janga, Hema Pamulapati, Arun Kanmanthareddy, Ajay Vallakati, Sampath Gunda, Sudharani Bommana, Misty Jaeger, Yeruva Madhu Reddy, Dhanunjaya Lakkireddy

Percutaneous left atrial appendage ligation (LAA) techniques have come to the forefront of management of atrial fibrillation (AF) patients who are at high risk of stroke and are unsuitable for oral anticoagulation therapy. LARIAT is a novel percutaneous endo-epicardial ligation technique for LAA exclusion. This technique is increasingly becoming popular for LAA exclusion in AF patients. A few studies have validated the efficacy of LARIAT in mitigating stroke risk in AF patients with contraindications to anticoagulation. Additionally a few studies have suggested that AF burden decreases after the LARIAT procedure. In this review paper we discuss the indications, technique and the latest advances in the LAA exclusion using the LARIAT system.

Destruction Of Medium Already Affected By Destructive Disorder: Fibrillating Atria Conceptually Need Therapeutic Help Rather Than Surgical Or Ablative Destruction

Citation: Petras Stirbys MD, PhD

Atrial fibrillation (AF) as the most common supraventricular arrhythmia is scarcely amenable to contemporary treatment. Due to the diverse origin and variable clinical course of AF there is a broad spectrum of therapy options. However, optimal AF management has not become a gold standard yet. In general, the recurrence rate of AF is most often clinically unacceptable despite drug, surgical and/or ablation therapy. Substrate-based approach and ongoing ablation of atrial wall in its selected areas including the vicinity of pulmonary veins can be harmful. Applied physical factors do produce total disintegration of cardiomyocites – both intra- and inter-cellular damage which, in turn, leads to functional hypo-/inactivation of atria irrespective of whether the sinus rhythm is restored or not. In fact, iatrogenic phenomenon of ablation-induced atrial incompetence did emerge. Heterogeneity in clinical results reflects the uncertainty regarding the efficacy, risks and benefits of invasive AF therapy. In this regard the overall burden of AF may increase when using current therapy methods. Applicability of destructive techniques is yet to be fully elucidated and discussed. We hypothesize that currently used ablation and/or surgical techniques are potentially harmful since the success rates are likely achieved through violation of atrial myocardium. That is why a new and well-designed therapeutic strategy is needed. Invention of highly selective curative methods producing fibrillatory/electric blockage with concomitant saving of atrial transport function is to be encouraged.

Who Needs Pharmacologic Therapy?

Citation: Christopher P. Porterfield, MD MPH and Rohit Malhotra, MD

Treatment of atrial fibrillation has evolved significantly in the last ten years, with ablation becoming a far more common form of treatment for this most common type of arrhythmias. However, while ablation has become more common, certain populations derive continued benefit from the use of pharmacologic therapy for treatment. We review the use of pharmacologic therapy and novel considerations for treatment of atrial fibrillation.

A Case Of Acute Thromboembolic Renal Infarction Associated With Paroxysmal Atrial Fibrillation

Citation: Macit Kalcik,MD, Mahmut Yesin, MD, Lutfi Ocal,MD, Taylan Akgun, MD, Nursen Keles,MD, Mustafa Ozan Gursoy, MD, Mehmet Ozkan, MD

Infarction of the kidney is an uncommon condition that can result from obstruction or decrease of renal arterial flow. The diagnosis is often delayed because it can mimic many other pathologic states, including pyelonephritis, renal colic, acute abdomen, pancreatitis and more. A high index of suspicion is important for prompt diagnosis. We describe a 20-year-old man presented with abdominal and right flank pain and hematuria. A computed tomography scan with intravenous contrast showed partial infarction of right renal parenchyma and selective renal angiography showed complete occlusion of the right renal artery which was also supplied by an accessory renal artery. Electrocardiography showed normal sinus rhythm. Transthoracic and transesophageal echocardiographic findings were unremarkable except for mild spontaneous echo contrast (SEC) in the left atrial appendage. Subsequent 48-hour holter monitor revealed frequent premature atrial complexes and paroxysmal atrial fibrillation (PAF). Development of thromboembolic renal infarction was attributed to the presence of PAF and concurrent SEC in the left atrial appendage (LAA). Low molecular weight heparin(LMWH) was followed by oral anticoagulant and an electrophysiologic study was planned for the management of PAF after 4 weeks of anticoagulation.

Observations Of Electrical Coupling Index Using The Contact™ System During Pulmonary Vein Electrical Isolation Procedures

Citation: Daniel T. Walker B. App Sci1, Karen P. Phillips MBBS

The Contact (St Jude Medical) System uses a novel impedance- based measure of Electrical Coupling Index (ECI) to assess the quality of catheter tip to endocardium contact. We sought to establish average ECI measurements and behaviour during pulmonary vein (PV) isolation procedures.

Forty-five patients undergoing PV isolation for atrial fibrillation (AF) were studied. ‘Non-contact’ and upper range ‘in-contact’ catheter positioning was performed for system calibration. ECI measurements were recorded pre-ablation at 14 standardized locations around the PV antra.

The mean ECI non-contact value was 77 ± 11 (range 63–107); the mean upper range in-contact value was 111 ± 16 (range 81–145). Mean ECI values pre-ablation around the PV antra ranged from 85 ± 18 to 107 ± 19. A trend towards higher mean ECI values was noted with increasing body mass index (BMI). Pre-ablation mean ECI values were 92 ± 10 (BMI 20-25), 95 ± 12 (BMI 26-30) and 104 ± 11 (BMI >30) (p< 0.01 for 20-25 vs. >30). A positive correlation was noted for mean pre-ablation ECI values and BMI (r=0.50).

An expected range of ECI values during PV isolation has been documented in this study. Observed ECI values correlate with patient BMI. The potential limitations of the current generation Contact System and scope for future clinical applications are discussed.

Use Of Rate And Rhythm Control Drugs In Patients Younger Than 65 Years With Atrial Fibrillation

Citation: Nancy M. Allen LaPointe, PharmD, MHS, Yuliya Lokhnygina, PhD, Jacqueline Rimmler, MS, Gillian D. Sanders, PhD, Eric D. Peterson, MD, MPH, Sana M. Al-Khatib, MD, MHS

Little is known about the use of pharmacologic rhythm or rate control in younger atrial fibrillation (AF) patients in clinical practice. Using commercial health data from 2006 through 2010, patients aged <65 years with an initial AF encounter were categorized as receiving pharmacologic rhythm- or rate-control treatment. Factors associated with each treatment were determined. Cox models with inverse propensity-weighted estimators were used to compare times to AF, heart failure, cardiovascular, non-cardiovascular, and any-cause hospitalizations. Of 79,232 patients meeting the study criteria, 12,408 (16%) received a rhythm-control drug and 66,824 (84%) received only rate-controlling drugs. Only 2% and 0.1%, respectively, received electrical cardioversion and AF ablation during the initial AF encounter. Patients who were men (OR 1.10, 95% CI 1.06–1.15), had index encounters in later years (2010 versus 2006: OR 1.34, 95% CI 1.23–1.45), were in the southern United States, and had other cardiac comorbidities were more likely to receive a rhythm-control drug. There was a greater risk of AF (HR 1.40, 95% CI 1.31–1.50), cardiovascular (HR 1.26, 95% CI 1.20–1.33), and all-cause (HR 1.11, 95% CI 1.07–1.16) hospitalizations in the rhythm-control group, but there was no difference between groups in heart failure (HR 1.01, 95% CI 0.88–1.17) or non-cardiovascular (HR 1.04, 95% CI 0.99–1.09) hospitalizations. Among younger AF patients receiving initial pharmacologic treatment, antiarrhythmic drugs were used less frequently than only rate-controlling drugs, and were associated with a higher risk of subsequent hospitalization.

Electrical And Hemodynamic Evaluation Of Ventricular And Supraventricular Tachycardias With An Implantable Dual-Chamber Pacemaker

Citation: Claudio Pandozi MD1, Franco Di Gregorio BiolScD, Carlo Lavalle MD, Renato Pietro Ricci MD, Sabina Ficili MD, Marco Galeazzi MD, Maurizio Russo MD, Angela Pandozi MD, Furio Colivicchi MD, Massimo Santini MD

The discrimination between ventricular (VT) and supraventricular tachycardia (SVT) and the evaluation of their hemodynamic impact are essential issues in the arrhythmia management. A new pacing device features a tachycardia diagnostic system relying on simultaneous recording of the transvalvular impedance (TVI) and a special integrated electric signal derived by the whole set of endocardial electrodes (iECG). The iECG waveform is sensitive to the pattern of ventricular activation, similarly to the surface ECG. The TVI increases in systole and decreases in diastole and the amplitude of this cyclic fluctuation is an expression of the effectiveness of the pump function. In order to test the value of these signals in the analysis of a tachycardia, we have assessed the iECG and TVI modifications induced by different SVTs and tolerated and non-tolerated VTs, during electrophysiological (EP) studies.

In case of SVT, the ventricular component of the iECG maintained the same morphology as in sinus rhythm. The peak-peak amplitude of the TVI fluctuation was reduced to 66 ± 11 % of the individual sinus rhythm reference, but the signal was present at every beat and showed a remarkable stability (variation coefficient 0.19 ± 0.01). In case of VT, the ventricular component of the iECG was strikingly different than in sinus rhythm. Regular TVI fluctuation was observed with tolerated VTs (peak-peak amplitude 74 ± 6 %; variation coefficient 0.21 ± 0.04). In contrast, with non-tolerated VTs the TVI amplitude was depressed below 40%, and the signal was virtually absent in the event of very fast VT or VF.
Our results confirm that the iECG is a reliable tool to quickly discriminate VTs from SVTs and that TVI can provide information on the severity of the hemodynamic impairment produced by a tachycardia, with potential clinical benefit in the follow-up of pacemaker patients. Furthermore, the application of these signals to automatic algorithms of arrhythmia recognition might improve the specificity of therapy administration by an implantable defibrillator (ICD).

The Rate Of Complications Associated With Concomitant Use Of Dabigatran With Cryoballoon Ablation For Atrial Fibrillation

Citation: Valay Parikh, MD, Vratika Agarwal, MBBS, Jharendra Rijal, MBBS , Vinod Chainani, MD , Soad Bekheit, MD, PhD, FHRS, Marcin Kowalski, MD, FACC, FHRS

Introduction: Catheter ablation is an evolving therapeutic strategy for the management of atrial fibrillation (AF). It is associated with a risk of thromboembolic events. The peri-procedural anticoagulation management with warfarin has been successful in mitigating this risk. However, introduction of novel oral anticoagulants like dabigatran offers more flexibility in anticoagulation approaches. Previous studies had evaluated the safety and efficacy of dabigatran in the radiofrequency ablation, but data related to cryoballoon ablation is lacking.

Methods and Results:We performed a retrospective observational study involving patients who underwent cryoballoon ablation for drug-refractory, symptomatic AF while on dabigatran in periprocedural period. Thromboembolic, hemorrhagic or other complications occurring within the first 30 days after the ablation procedure were analysed.
Our study population comprised of 50 patients with mean age of 58.96 ± 3.54 years with 76% (n=38) being male. We found 3 (6%) minor complications in peri-procedural period including 2 groin hematomas and 1 trace asymptomatic pericardial effusion. There were no major intraprocedural or post procedural hemorrhagic or thromboembolic events. None of patients with the minor complications required significant additional workup or extended hospital stay. All the patients were able to continue dabigatran for 30 days without any additional side effects or complications.
Conclusion: Dabigatran is a safe and efficacious agent in patients undergoing cryoballoon AF ablation. 

Nonfluoroscopic Ablation Of Atrial Fibrillation Using Cryoballoon

Citation: Mansour Razminia, MD, FACC, Hany Demo, MD, Carlos Arrieta-Garcia, MD, Oliver J. D’Silva, MD, Theodore Wang, MD, FACC, Richard F. Kehoe, MD, FACC
Background: The conventional method of cryoballoon ablation of atrial fibrillation involves the use of fluoroscopy for visual guidance. The use of fluoroscopy is accompanied by significant radiation risks to the patient and the medical staff. Herein, we report our experience in performing successful nonfluoroscopic pulmonary vein isolation using cryoballoon ablation in 5 consecutive patients with paroxysmal atrial fibrillation.

Methods and Results: Five consecutive patients with paroxysmal atrial fibrillation underwent cryoballoon ablation for pulmonary vein isolation using a nonfluoroscopic approach. Pre-procedural cardiac computed tomography or cardiac magnetic resonance imaging was not performed in any patient. A total of twenty pulmonary veins were identified and successfully isolated (100%) with the guidance of intracardiac echocardiography and 3-dimensional electroanatomic mapping. No fluoroscopy was used for the procedures. There were no major procedural adverse events.

Conclusion: In an unselected group of patients undergoing cryoballoon ablation, a nonfluoroscopic approach is feasible and can be performed safely and effectively while eliminating the risks associated with radiation to both the patient and the medical staff.

Exploring New Frontiers in Atrial Fibrillation

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

Welcome to the June edition of JAFIB. Summer has been reasonably pleasant in continental United States so far. Hope our audience around the world had a wonderful professional and personal times.