Vance J. Plumb

Dabigatran versus Warfarin Therapy for Uninterrupted Oral Anticoagulation During Atrial Fibrillation Ablation

Uninterrupted oral anticoagulant (OA) therapy with warfarin has become the standard of care at many centers performing catheter ablation of atrial fibrillation (AF). Compared with warfarin, dabigatran, a direct thrombin inhibitor, has been demonstrated to reduce the risk of stroke in nonvalvular AF with similar bleeding risk. Few data exist on the safety profile of uninterrupted dabigatran therapy during AF ablation.

Idiopathic Ventricular Arrhythmias Originating from the Papillary Muscles in the Left Ventricle: Prevalence, Electrocardiographic and Electrophysiological Characteristics, and Results of the Radiofrequency Catheter Ablation

Idiopathic VAs Originating from the LV Papillary Muscles.u2002Introduction: Idiopathic ventricular arrhythmias (VAs) can originate from the left ventricular (LV) papillary muscles (PAMs). This study investigated the prevalence, electrocardiographic and electrophysiological characteristics, and results of catheter ablation of these VAs, and compared them with other LV VAs.

A novel electrocardiographic criterion for differentiating a left from right ventricular outflow tract tachycardia origin: the V2S/V3R index.

Although several ECG criteria have been proposed for differentiating between left and right origins of idiopathic ventricular arrhythmias (VA) originating from the outflow tract (OT‐VA), their accuracy and usefulness remain limited. This study was undertaken to develop a more accurate and useful ECG criterion for differentiating between left and right OT‐VA origins.

Idiopathic Left Ventricular Arrhythmias Originating Adjacent to the Left Aortic Sinus of Valsalva: Electrophysiological Rationale for the Surface Electrocardiogram

IVT Arising Adjacent to the Left Sinus of Valsalva. Background: Idiopathic ventricular arrhythmias (VAs) may be amenable to catheter ablation within or adjacent to the left sinus of Valsalva (LSOV). However, features that discriminate these sites have not been defined. The purpose of this study was to determine the electrocardiographic and electrophysiological features of VAs originating within or adjacent to the LSOV.

Elevated Defibrillation Threshold When Right‐Sided Venous Access is Used for Nonthoracotomy Implantable Defibrillator Lead Implantation

Right/Left‐Sided ICD Implantation. Introduction: Although myriad factors influence the defibrillation threshold, the relation between the site of transvenous lead entry into the vascular system and the defibrillation threshold has not been reported. This study examines the influence that venous entry site has on defibrillation success for a transvenous implantable cardioverter defibrillator lead with two defibrillating coils.

Differential Effect of Esmolol on the Fast and Slow AV Nodal Pathways in Patients with AV Nodal Reentrant Tachycardia

Esmolol Effect on AV Nodal Pathways. Introduction: AV nodal reentrant tachycardia (AVNRT) usually involves anterograde conduction over a slowly conducting (“slow”) pathway and retrograde conduction over a rapidly conducting (“fast”) pathway. A variety of drugs, such as beta blockers, digitalis, and calcium channel blockers, have been reported to prolong AV nodal refractoriness in both the anterograde and retrograde limbs of the circuit. However, few data are available that address whether the fast and slow pathways respond in a quantitatively different manner to drugs such as beta‐adrenergic antagonists. In addition, it is not known whether the effects of these agents on refractoriness parallel the effects on conduction in the fast and slow pathways. The present study was performed to measure the effect of the intravenous beta‐adrenergic agent, esmolol, on refractoriness and conduction in both the fast and slow AV nodal pathways in patients with AVNRT.

Non‐Pulmonary Vein Epicardial Foci of Atrial Fibrillation Identified in the Left Atrium after Pulmonary Vein Isolation

Background: Pulmonary vein (PV) isolation (PVI) has been demonstrated to be an effective technique for curing atrial fibrillation (AF). AF foci that cannot be isolated by PVI (non‐PV foci) can become the cause of AF recurrence. The purpose of this study was to investigate the characteristics of non‐PV AF foci.

Successful reduction of a high defibrillation threshold by a combined implantation of a subcutaneous array and azygos vein lead.

A 72‐year‐old man with nonischemic cardiomyopathy was referred because his implantable cardioverter defibrillator had failed to terminate spontaneous ventricular fibrillation (VF). Defibrillation threshold (DFT) testing confirmed that 830‐V shocks failed to defibrillate VF despite optimization of the biphasic waveform and reversal of shock polarity. The placement of a new right ventricular lead and the addition of a subcutaneous array failed to defibrillate VF at 830 V. The combination of a subcutaneous array and azygos vein coil successfully defibrillated VF. The mechanism for successful DFT reduction was likely greater current supplied to the posterior basal left ventricle by the azygos vein lead. (PACE 2012; 35:e173–e176)

Combined Femoral Pseudoaneurysm and Arteriovenous Fistula: Diagnosis by Doppler Color Flow Mapping

This case report is the first to describe a combined femoral pseudoaneurysm and arteriovenous fistula resulting from a cardiac catheterization, diagnosed by color Doppler.

Adenosine can also improve the conduction between the superior vena cava and right atrium after isolation.

A 64‐year‐old man with atrial tachycardia (AT) 3 years after a superior vena cava (SVC) isolation for atrial fibrillation underwent electrophysiologic testing. SVC mapping with a basket catheter revealed a more frequent activation in the SVC than in either of the atria during the AT and consequently the recovered conduction between the SVC and right atrium. The conduction improved from 3 or 4–1 conduction to 2–1 conduction after adenosine was administered. Ectopic firing in the SVC persisted even after restoration of sinus rhythm by the successful SVC isolation, which was confirmed by adenosine.