Wednesday, February 4, 2009

14th Annual Boston Atrial Fibrillation Symposium Proceedings – Technology Round Up


Citation :Dhanunjaya Lakkireddy.14th Annual Boston Atrial Fibrillation Symposium Proceedings – Technology Round Up .JAFIB.2009 Feb;Volume 1 Issue(5): 304-307.

What started off as a small, cozy meeting of electrophysiologists thinking about atrial fibrillation (AF) evolved into a major annual program that draws more audience every year. Thanks to the vision of Dr. Jeremy Ruskin (Massachussets General Hospital, Boston) who started this program and continues to direct it very effectively to this day. Over the last few years, industry has used this as a good platform to showcase some of their latest technology in AF therapy. Several products ranging from radiation protection devices to most advanced mapping and ablation systems have been displayed at the Seaport Hotel.

Review on "Atrial Fibrillation Progression: New Insight in The Natural History of This Arrhythmia"


Citation :Sanjay Dixit.Review on "Atrial Fibrillation Progression: New Insight in The Natural History of This Arrhythmia" .JAFIB.2009 Feb;Volume 1 Issue(5): 301-303.

The past decade has witnessed a dramatic shift in our approach to the management of atrial fibrillation (AF) . This can largely be attributed to the advent of catheter ablation therapy which has proven to be significantly more efficacious in achieving arrhythmia control than antiarrhythmic drugs . However, despite these developments, there is paucity of data on the natural history of this arrhythmia and studies that have been conducted so far to evaluate this aspect of AF behavior, are mostly retrospective . Thus, there is a growing need to assess AF progression on a prospective basis.

Review on "High-Density Mapping of Atrial Fibrillation in Humans: Relationship Between High-Frequency Activation and Electrogram Fractionation"


Citation :Yaariv Khaykin.Review on "High-Density Mapping of Atrial Fibrillation in Humans: Relationship Between High-Frequency Activation and Electrogram Fractionation" .JAFIB.2009 Feb;Volume 1 Issue(5): 298-300.

Catheter ablation has rapidly gained acceptance as a mainstay of therapy for many symptomatic patients with atrial fibrillation since the original publication by the Bordeaux group . Early on it became apparent that in most patients with paroxysmal AF, the arrhythmia was initiated by focal firing in the pulmonary veins. Ablation focused on elimination of such triggers and was largely limited to patients who would stay in sinus rhythm long enough to allow successful mapping within the pulmonary veins. As this was time consuming and was associated with high risk of developing pulmonary vein stenosis, ablation lesions were moved further and further away from the sources of focal firing with co-development of Circumferential Pulmonary Vein Ablation (CPVA) aiming to encompass pulmonary vein ostia with circular lesions without verification of conduction block and Segmental Pulmonary Vein Isolation evolving into Pulmonary Vein Antrum Isolation with the targeted area similar to that in CPVA but with requisite documentation of entry and / or exit block of conduction.

Anticoagulation During AF Ablation: The Balance Between Thromboembolism And Bleeding


Citation :Jennifer A. Mears, Samuel J. Asirvatham.Anticoagulation during AF Ablation: The Balance Between Thromboembolism and Bleeding .JAFIB.2009 Feb;Volume 1 Issue(5): 285-297.

Radiofrequency ablation for atrial fibrillation is being increasingly used to treat patients with symptomatic arrhythmia. The procedure is complex and associated with significant complications including thromboembolism, stroke, and bleeding.

Despite significant advances in catheter design, online cardiac imaging, and greater operator experience, both stroke and major vascular complications continue to be problematic.

Increasing the duration and intensity of anticoagulation has been the primary modality used to decrease thromboembolism. However, these measures increase the likelihood and severity of bleeding-related complications. The optimal method of anticoagulation along with the adjunctive use of technology to decrease vascular complications and mechanically prevent cerebral embolization is unknown.

In this paper, we review the present methods used by ablationists to decrease the likelihood of thromboembolism during atrial fibrillation. We then describe methods used to decrease bleeding and vascular complications at access sites as well as cardiac perforation. We briefly discuss newer techniques to decrease endovascular complications including epicardial ablation and the use of temporarily implanted vascular protection devices.

Finally, we describe the best option or combination of approaches that attempt to balance the risks of thromboembolism and bleeding during AF ablation.

Are Balloon Based Strategies Better Than Conventional Radiofrequency Catheter Ablation: Exploring New Frontiers In The Treatment Of AtrialFibrillation


Citation : Alexander Fuernkranz, Julian Chun, Boris Schmidt, Karl-Heinz Kuck, Feifan Ouyang.Are balloon based strategies better than conventional radiofrequency catheter ablation: Exploring new frontiers in the treatment of atrial fibrillation .JAFIB.2009 Feb;Volume 1 Issue(5): 279-284.

Paroxysmal atrial fibrillation can be eliminated with continuous circular linear lesions around the pulmonary veins using radiofrequency ablation. Due to the technical complexity of this procedure balloon-based devices have been developed to simplify pulmonary vein isolation. Cryoballoon ablation provides excellent safety and is technically less demanding when compared to radiofrequency catheter ablation in selected patients. In this review, advantages as well as drawbacks of this emerging technology in relation to standard catheter ablation are discussed.

Cardiovascular Risk Factors and Atrial Fibrillation: What is the Link?


Citation :Yaariv Khaykin.Cardiovascular Risk Factors and Atrial Fibrillation: What is the Link? .JAFIB.2009 Feb;Volume 1 Issue(5): 277-278.

Atrial fibrillation is a common cardiac arrhythmia. It is well known to occur in older patients with comorbid conditions such congestive heart failure and ischemic heart disease . In these otherwise sick individuals it is associated with higher long term morbidity and mortality .In their paper published in the February issue of JAFIB, Dr. Barrios and colleagues further examine the association between atrial fibrillation, classical coronary risk factors, proven cardiovascular preventive therapies and end-organ damage in 2024 patients with documented hypertension and coronary heart disease.

Accurate Detection Of Left Atrial Thrombus Prior To Atrial Fibrillation Ablation In Patients With Therapeutic Anticoagulation: Does Transesophageal


Citation :Dhanunjaya Lakkireddy.Accurate Detection Of Left Atrial Thrombus Prior To Atrial Fibrillation Ablation In Patients With Therapeutic Anticoagulation: Does Transesophageal Echocardiography Beat Conventional Wisdom? .JAFIB.2009 Feb;Volume 1 Issue(5): 308-310.

Atrial fibrillation (AF) significantly increases the risk of left atrial (LA) thrombus and systemic thromboembolism . Screening transesophageal echo (TEE) to rule out left atrial thrombus has become standard of care over the years . Conventional thinking of therapeutic anticoagulation for 4-6 weeks prior to cardioversion may not reduce the risk of left atrial thrombus completely. Left atrial thrombi can be seen on 2-9% of screening TEEs in AF patients with various levels of anticoagulation . Radiofrequency ablation of atria with pulmonary vein isolation (PVI) with or without various additional ablative techniques has evolved into very important strategy in the treatment of patients with AF .

QT Prolongation Following Ectopic Beats: Initial Data Regarding the Upper Limit of Normal with Possible Implications for Antiarrhythmic Therapy


Alyssa J. Reiffel, James A. Reiffel.QT Prolongation Following Ectopic Beats: Initial Data Regarding the Upper Limit of Normal with Possible Implications for Antiarrhythmic Therapy and Concealed (Unexpressed) Long QT .JAFIB.2009 Feb;Volume 1 Issue(5): 270-276.

Ectopic beats are frequently associated with morphologic repolarization alterations of ensuing sinus beats. Less is known about repolarization duration alterations of post-ectopic sinus beats. In one patient who developed long QT and torsades de pointes upon exposure to a class III antiarrhythmic drug, and was later genotyped as being a carrier for long QT syndrome (LQTS) type 1, review of a pre-drug Holter monitor study revealed marked QT prolongation of post-ectopic sinus beats. In wondering whether this might be a common clue to “concealed” unexpressed LQTS, we realized that we must first characterize the range of post-ectopic QT prolongation present in normals. Prolongation beyond the upper limit of this range might then raise suspicion of possible LQTS and alter the antiarrhythmic drug selection process for the suppression of atrial fibrillation or other arrhythmias. Accordingly we performed this study to determine the presence/degree of repolarization prolongation in normal individuals following premature ectopic impulses. We found that QT prolongation is common in post ectopic sinus beats but that the uncorrected QT interval of post-ectopic beats in normals never exceeded 480 ms in duration which was much shorter than that seen (510-590 ms) in our gene carrier.

Atrial fibrillation and coronary heart disease: fatal attraction


Citation :Vivencio Barrios, Carlos Escobar, Rocio Echarri.Atrial fibrillation and coronary heart disease: fatal attraction .JAFIB.2009 Feb;Volume 1 Issue(5): 262-269.

In this manuscript, the profile and clinical management of hypertensive patients with chronic ischemic heart disease and atrial fibrillation (AF) is examined and whether high heart rate is associated with a different profile is determined. CINHTIA was a cross-sectional and multicenter survey aimed to define the clinical profile of hypertensive patients with chronic ischemic heart disease daily attended in Spain. Blood pressure, LDL-cholesterol and diabetes control rates were established according to ESH-ESC 2003, NCEP-ATP III and ADA 2005 guidelines, respectively. Out of the 2024 patients, 338 (16.7%) exhibited AF. The group of patients with AF was older and with higher prevalence of diabetes, organ damage and cardiovascular disease. Blood pressure (41.8% vs 34.5%, p=0.014) and diabetes (28.5% vs 20.9%,p=0.044) were worse controlled in patients with AF, with a trend to a lower control of LDL-cholesterol (31.2% vs 26.8%, p=0.093). When distributing patients with AF according to heart rate, except for smoking, left ventricular hypertrophy and peripheral arterial disease that were more frequent in those with higher heart rate, no significant differences were found in other risk factors or organ damage between groups. Blood pressure, glycemia and LDL-cholesterol were worse controlled in the subgroup with highest heart rate. In clinical practice, hypertensive patients with chronic ischemic heart disease and AF have a bad prognosis not only due to a worse clinical profile, but also due to lower risk factors control rates. In contrast with patients at sinus rhythm, higher heart rate was a weaker predictor of outcomes in subjects with AF.

Presence of left atrial appendage thrombus in patients presenting for left atrial ablation of atrial fibrillation despite pre-operative anticoagulatio


Citation : Joseph P. de Bono, Sacha Bull, John Paisey, David Tomlinson, Kim Rajappan, Yaver Bashir, Harald Becher and Timothy R Betts.Presence of left atrial appendage thrombus in patients presenting for left atrial ablation of atrial fibrillation despite pre-operative anticoagulation. .JAFIB.2009 Feb;Volume 1 Issue(5): 257-261.

Background:

One of the recognised complications of left atrial ablation for atrial fibrillation (AF) is stroke. Left atrial (LA) thrombus, which may be dislodged by catheter manipulation, is an absolute contraindication to ablation. It is unclear whether imaging of the left atrial appendage (LAA) by transesophageal echo (TEE) is mandatory to exclude LA clot prior to ablation, particularly in “low-risk” patients with paroxysmal AF and normal left ventricular (LV) function.

Methods and results:

We carried out a retrospective analysis of pre-ablation TEE in patients presenting for ablation of AF. All patients received a minimum of 4 weeks therapeutic anticoagulation before stopping oral anticoagulants 3 days before their procedure. Images from 244 ablation procedures carried out in 148 patients were examined, including 106 patients with paroxysmal AF and normal LV function.

Despite at least 4 weeks of pre-operative therapeutic anticoagulation with Coumadin (INR>2.0), LAA thrombus was identified in 4 patients (2.7%). These included 2 patients with paroxysmal AF and normal LV function, although both had a high arrhythmia burden. The thrombi regressed with intensification of anticoagulation.

Conclusions:

In conclusion, pre-operative imaging of the LAA remains advisable to exclude thrombus prior to ablation for AF even in patients with paroxysmal AF and normal LV function.