Abhishek Maan

Speckle echocardiographic left atrial strain and stiffness index as predictors of maintenance of sinus rhythm after cardioversion for atrial fibrillation: a prospective study

BackgroundEchocardiographic left atrial (LA) strain parameters have been associated with atrial fibrillation (AF) in prior studies. Our goal was to determine if strain measures [peak systolic longitudinal strain (LAS) and stiffness index (LASt)] changed after cardioversion (CV); and their relation to AF recurrence.Methods and results46 participants with persistent AF and 41 age-matched participants with no AF were recruited. LAS and LASt were measured before and immediately after CV using 2D speckle tracking imaging (2DSI). Maintenance of sinus rhythm was assessed over a 6-month follow up. Mean LAS was lower, and mean LASt higher, in participants with AF before CV as compared to control group (11.9 ± 1.0 vs 35.7 ± 1.7, p<0.01 and 1.31 ± 0.17 vs 0.23 ± 0.01, p<0.01, respectively). There was an increase in the mean LAS immediately after CV (11.9 ± 1.0 vs 15.9 ± 1.3, p<0.01), whereas mean LASt did not change significantly after CV (p=0.62). Although neither LAS nor LASt were independently associated with AF recurrence during the follow-up period, change in LAS after cardioversion (post-CV LAS – pre-CV LAS) was significantly higher among individuals who remained in sinus rhythm when compared to individuals with recurrent AF (3.6 ± 1.1 vs 0.4 ± 0.8, p=0.02).ConclusionsLAS and LASt differed between participants with and without AF, irrespective of the rhythm at the time of echocardiographic assessment. Baseline LAS and LASt were not associated with AF recurrence. However, change in LAS after CV may be a useful predictor of recurrent arrhythmia.

Impact of Atrial Fibrillation on Outcomes in Patients Who Underwent Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) has emerged as an alternative treatment for surgical high-risk patients with severe aortic stenosis. The aim of this study was to determine the impact of atrial fibrillation (AF) on procedural outcomes. Data from 137 patients who underwent TAVR using Edwards SAPIEN valve were reviewed. The predictors of new-onset atrial fibrillation (NOAF) after the procedure were analyzed. In addition, the post-TAVR clinical outcomes and adverse events were compared according to the presence and absence of preprocedural and postprocedural AF. Previous AF was present in 49% of the patients who underwent TAVR. After the procedure, NOAF was detected in 21% of patients, and the cumulative incidence of post-TAVR AF was 60%. After TAVR, 50% of all the episodes of NOAF occurred in the initial 24 hours after the procedure. Transapical approach was observed to an important predictor of NOAF (adjusted odds ratio [OR] 5.05, 95% confidence interval [CI] 1.40 to 18.20, p = 0.013). The composite outcome of all-cause mortality, stroke, vascular complications, and repeat hospitalization in 1 month after TAVR was significantly higher in patients with previous AF (33 of 67 vs 19 of 70, adjusted OR 2.60, 95% CI 1.22 to 5.54, p = 0.013) compared with patients who did not have previous AF. The presence of post-TAVR AF led to a prolongation in the duration of intensive care unit stay by an average of 70 hours (95% CI 25 to 114.7 hours, p = 0.002). Similarly, post-TAVR AF also led to the prolongation in the hospital stay by an average of 6.7 days (95% CI 4.69 to 8.73 days, p <0.0005). In conclusion, our study demonstrates that the presence of AF before TAVR is an important predictor of the composite end point of all-cause mortality, stroke, vascular complications, and repeat hospitalization in 1 month after the procedure. AF after TAVR is more likely to be encountered with the transapical approach and is associated with a prolongation of intensive care unit and hospital stay.

Newer anticoagulants in cardiovascular disease: a systematic review of the literature.

Vitamin K antagonists (VKAs) such as warfarin have traditionally been the major therapeutic option for anticoagulation in clinical practice. VKAs are effective and extensively recommended for the prevention of venous and arterial thromboembolism in cardiovascular disease. Despite its effectiveness, warfarin is limited by factors such as a narrow therapeutic index, drug-drug interactions, food interactions, slow onset and offset of action, hemorrhage, and routine anticoagulation monitoring to maintain therapeutic international normalized ratio. During the last 2 decades, the approval of anticoagulants, such as low-molecular-weight heparins, indirect factor Xa inhibitors (eg, fondaparinux), and direct thrombin inhibitors (eg, argatroban, lepirudin, and desirudin), have expanded the number of available antithrombotic compounds with additional targets within the anticoagulation pathway. Although these medications offer several potential therapeutic advantages, they all require parenteral or subcutaneous administration and are substantially more expensive than VKAs. Thus, VKAs, despite several limitations, have remained the major option for most patients requiring chronic anticoagulation. These limitations have prompted interest in the development of newer oral anticoagulants. Novel anticoagulants targeting inhibition of factor Xa and thrombin (factor IIa) have now been incorporated into clinical practice based on the results of large randomized clinical trials, with the recent U.S. Food and Drug Administration approval of dabigatran for stroke prevention in atrial fibrillation and rivaroxaban for deep vein thrombosis and stroke prevention in atrial fibrillation, with multiple other agents in various stages of development for these and other indications. This review discusses the pharmacological properties, clinical results, and therapeutic applications of novel and new anticoagulants, thereby providing an outline for the future of anticoagulation in cardiovascular disease.

Complications from catheter ablation of atrial fibrillation: a systematic review.

Atrial fibrillation (AF) is the most common arrhythmia requiring treatment that is encountered in clinical practice. Recent advances in the understanding of underlying mechanisms of AF have led to the increased use of catheter ablation (CA) as a treatment modality for paroxysmal, persistent, or long-standing persistent AF in patients with symptomatic AF despite treatment with antiarrhythmic medications. Because of the complexity in technique and anatomic location of the ablation sites, it is not surprising that CA of AF is associated with a greater risk of procedural complications compared with simpler cardiac ablation procedures. Major and minor complications, including life-threatening complications, have been described and quantified. This systematic review describes the potential risks of CA that have been reported over a period and provides insights into the evolving strategies to minimize these complications, thus making CA techniques safer and potentially more efficacious for AF.

Incidence and Predictors of Pacemaker Implantation in Patients Undergoing Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) has emerged as an alternative treatment for patients with symptomatic aortic stenosis who are at high risk for surgical aortic valve replacement. The development of conduction abnormalities is a major complication in the postprocedural period of TAVR.

Obstructive Sleep Apnea and Atrial Fibrillation: Pathophysiology and Implications for Treatment.

Obstructive sleep apnea (OSA) is increasingly recognized as an important risk factor for arrhythmogenesis. Epidemiological and clinical studies have suggested a strong association between OSA and atrial fibrillation (AF). With the increasing global epidemic of obesity, the incidence of OSA is also expected to rise. Various mechanisms mediated through adverse electrical and structural changes have been proposed to explain the increased risk of AF in patients with OSA. Multiple studies have also observed a greater risk of AF recurrence after cardioversion and catheter ablation (CA) in the patients with untreated OSA. The epidemiological and pathophysiological associations between OSA and AF have significant implications on the treatment outcomes of rhythm-control strategies for AF. Adequate screening and optimal management of OSA are of key importance to help improve the clinical outcomes following cardioversion and CA. In this review, we sought to describe the role of various mechanisms by which OSA mediates the pathogenesis of AF and contributes to adverse outcomes following CA.

Practical issues in the management of novel oral anticoagulants-cardioversion and ablation.

Recent research and publication of various landmark trials have led to the approval and subsequent use of novel oral anticoagulants (NOACs) in clinical practice. The use of these newer agents for anticoagulation offers several benefits such as greater specificity, relatively rapid onset and offset of action and a predictable pharmacological profile as compared to warfarin. With the increasing use of these agents, several key issues ranging from appropriate selection to management of complications and considerations for concurrent procedures (cardioversion and catheter ablation) have also emerged. The timing of interruption of anticoagulants prior to catheter ablation and re-initiation after the procedure to minimize the peri-procedural thromboembolism risk without increasing the bleeding risk is of key relevance in electrophysiology practice. The use of NOACs in patients undergoing catheter ablation and cardioversion also requires special considerations based on the pharmacological properties of the individual agent and the presence of comorbidities such as renal and or hepatic impairment. In this review we aim to discuss the practical considerations with the use of NOACs in the setting of cardioversion and catheter ablation based on the currently available data.

Impact of catheter ablation on P-wave parameters on 12-lead electrocardiogram in patients with atrial fibrillation.

BACKGROUND Catheter ablation has emerged as a widely used treatment modality for atrial fibrillation (AF). P-wave abnormalities have been described in the patients with AF, and catheter ablation may potentially further impact P-wave parameters due to ablation of atrial tissue. METHODS We reviewed data on P-wave parameters (P-wave duration, amplitude and P-wave duration and amplitude product) in leads V1 and aVF and changes in the P-terminal force (Ptf; product of duration and amplitude of terminal part of P-wave) in lead V1 from 12-lead electrocardiograms obtained prior to and after CA of a total of 46 (28 paroxysmal and 18 persistent) AF patients. RESULTS The median age of patients in our study was 63 (range: 30-77) years. We noticed a significant reduction in the P-wave duration (from 87.39±28.62ms at baseline to 72.09±24.59ms; p=0.0072) and the product of P-wave duration and amplitude in lead V1 (12.16±5.54mVms at baseline to 8.30±5.78mVms, p=0.0015) after CA. There was also a significant decrease in P-wave duration (from 92.57±19.67ms at baseline to 76.48±16.32ms after CA, p=0.0001) and P-wave duration and amplitude product in lead aVF (12.61±4.05mVms at baseline to 9.77±3.86mVms after CA, p=0.0001). CA also led to a significant decrease in Ptf (from 4.56±1.88 at baseline to 2.85±1.42mVms, p<0.0001). CONCLUSION Radiofrequency catheter ablation of AF leads to modification of P-wave parameters with substantial diminution in both the amplitude and duration of the P-wave in leads V1 and aVF. This likely represents reduction in electrically active atrial tissue after ablation, and may serve as a marker for the extent of ablated atrial tissue.

Management strategies in atrial fibrillation in patients with heart failure

Atrial fibrillation (AF) and heart failure (HF) frequently occur together, and their coexistence is associated with a poor prognosis. AF and HF share risk factors, but their relationship involves complex hemodynamic, neurohormonal, inflammatory, ultrastructural, and electrophysiologic processes that extend beyond epidemiological associations. The shared mechanisms underlying AF and HF have important implications for the treatment of AF in patients with HF. This article focuses on reviewing contemporary data as it pertains to AF management in patients with HF and provides insight into investigational therapies currently under development.

Current Evidence and Recommendations for Rate Control in Atrial Fibrillation.

Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice, which is associated with substantial risk of stroke and thromboembolism. As an arrhythmia that is particularly common in the elderly, it is an important contributor towards morbidity and mortality. Ventricular rate control has been a preferred and therapeutically convenient treatment strategy for the management of AF. Recent research in the field of rhythm control has led to the advent of newer antiarrhythmic drugs and catheter ablation techniques as newer therapeutic options. Currently available antiarrhythmic drugs still remain limited by their suboptimal efficacy and significant adverse effects. Catheter ablation as a newer modality to achieve sinus rhythm (SR) continues to evolve, but data on long-term outcomes on its efficacy and mortality outcomes are not yet available. Despite these current developments, rate control continues to be the front-line treatment strategy, especially in older and minimally symptomatic patients who might not tolerate the antiarrhythmic drug treatment. This review article discusses the current evidence and recommendations for ventricular rate control in the management of AF. We also highlight the considerations for rhythm control strategy in the management of patients of AF.