Samuel J. Asirvatham

Long-term outcome of atrial fibrillation ablation: Impact and predictors of very late recurrence

Long‐Term Outcome of AF Ablation. Introduction: Ablation eliminates atrial fibrillation (AF) in studies with 1 year follow‐up, but very late recurrences may compromise long‐term efficacy. In a large cohort, we sought to describe the determinants of delayed recurrence after AF ablation.

Outcomes After Cardiac Perforation During Radiofrequency Ablation of the Atrium

Background: Perforation during catheter procedures in either the atrium or ventricle is relatively uncommon, but potentially fatal if tamponade ensues. This study analyzes the occurrence and outcomes of cardiac perforation during catheter‐based radiofrequency ablation procedures in the left atrium.

Correlative anatomy for the invasive electrophysiologist: outflow tract and supravalvar arrhythmia.

Radiofrequency ablation in the outflow tract and great arteries is increasingly performed to treat a variety of symptomatic cardiac arrhythmias. The regional anatomy of these structures is among the most complex of those encountered by cardiac electrophysiologists. An exact appreciation of the relationships between these overlapping structures and their proximity to the coronary arterial and conduction system is essential for rational, safe, and effective ablation for these arrhythmias. A supravalvar portion of the aorta is a unique site for arrhythmia origin where the arrhythmogenic substrate for atrial arrhythmias, ventricular arrhythmias, and accessory pathways may all be located. Discussed in this review are the main principles of outflow tract and supravalvar arrhythmia, and these are correlated with fluoroscopy, electrograms, and electrocardiography that help guide the invasive electrophysiologist.

Percutaneous epicardial left atrial appendage closure: preliminary results of an electrogram guided approach.

Background: Pharmacologic therapies to prevent stroke in atrial fibrillation (AF) have numerous limitations, prompting the development of device‐based therapies. We investigated whether an electrogram‐based approach using a novel hollow suture can safely capture and ligate the left atrial appendage (LAA).

Correlative Anatomy and Electrophysiology for the Interventional Electrophysiologist

The cavotricuspid isthmus (CVTI) is the well‐established location of atrial tissue critical for the maintenance of typical atrial flutter. The CVTI begins at the electrically inert tricuspid valve and includes the atrial myocardium up to the inferior vena cava (IVC).

Risk Factors for Implantable Defibrillator Lead Fracture in a Recalled and a Nonrecalled Lead

Risk Factors for ICD Lead Fracture. Introduction: The Medtronic Sprint Fidelis® implantable cardioverter defibrillator (ICD) lead was “recalled” in October 2007 after 268,000 implants worldwide due to increased failure risk. Manufacturer suggested monitoring has not been shown effective at preventing adverse events. Only limited data exist regarding clinical predictors of Fidelis® lead fracture. We sought to identify risk factors for Fidelis® fracture to guide clinical monitoring and compare its performance with a control lead.

Use of the impella™ microaxial blood pump for ablation of hemodynamically unstable ventricular tachycardia

Impella™ for VT Ablation. Ablation for ventricular tachycardia remains a challenge with suboptimal procedural success rates. One of the major causes of difficulty is precipitous hypotension when ventricular tachycardia is induced precluding even rapid mapping of the arrhythmia. We report the successful use of the Impella™ microcirculatory axial blood flow pump in 3 patients with hemodynamically unstable ventricular tachycardia that allowed successful completion of the procedure. In these 3 patients, there was no evidence of Impella™‐related valvular disturbance, iatrogenic ventricular arrhythmias, or interference with mapping and ablation catheter movement. (J Cardiovasc Electrophysiol, Vol. 21, pp. 458‐4, April 2010)

No Increased Bleeding Events with Continuation of Oral Anticoagulation Therapy for Patients Undergoing Cardiac Device Procedure

Background: Switching warfarin for heparin has been a practice for managing periprocedural anticoagulation in high‐risk patients undergoing device‐related procedures. We sought to investigate whether continuation of warfarin sodium therapy without heparin bridging is safe and, when it is continued, the optimal international normalized ratio (INR) without increased bleeding risk at time of device‐related procedure.

Noise, artifact, and oversensing related inappropriate ICD shock evaluation: ALTITUDE noise study.

Background: Approximately 12–21% of implantable cardioverter defibrillator (ICD) patients receive inappropriate shocks. We sought to determine the incidence and causes of noise/artifact and oversensing (NAO) resulting in ICD shocks.

Successful ablation of atrial tachycardia in the right coronary cusp of the aortic valve in a patient with atrial fibrillation: what is the substrate?

Atrial tachycardias have been successfully ablated from the noncoronary cusp of the aortic valve. The anatomical substrate responsible for the arrhythmia in these patients is unknown. We report a case of intracardiac ultrasound confirmed ablation in the right coronary cusp of the aortic valve. Pacing maneuvers performed in this case, along with the regional anatomy of the right coronary cusp, strongly suggest that the ablated substrate is muscular extensions above the aortic valve. Ablation in the right coronary cusp eliminated tachycardia without valve damage or AV conduction abnormality.