BACKGROUND Phase 2 reentry caused by heterogeneous loss of the transient outward potassium current (I(to))-mediated epicardial action potential (AP) dome can produce a closely coupled R-on-T extrasystole leading to ventricular fibrillation (VF) under conditions of ST-segment elevation unrelated to ischemia. The present study examined the role of phase 2 reentry in the initiation of VF during ea...

Functional reentry has been hypothesized to be an underlying mechanism of ventricular fibrillation (VF); however, its contribution to activation patterns during fully developed VF is unclear. We applied new quantitative pattern analysis techniques to mapping data acquired from a 21 x 24 unipolar electrode array (2-mm spacing) located on the ventricular epicardium of 7 open-chest, unsupported pi...

RATIONALE the rapid delayed rectifier potassium current, I(Kr), which flows through the human ether-a-go-go-related (hERG) channel, is a major determinant of the shape and duration of the human cardiac action potential (APD). However, it is unknown whether the time dependency of I(Kr) enables it to control APD, conduction velocity (CV), and wavelength (WL) at the exceedingly high activation fre...

T he landscape for assessing the public health implications of prisoner reentry in California has changed dramatically over the past few years. First, California (and the nation as a whole) is in the midst of a deep and persistent recession, which has significantly weakened the health care safety net that ex-prisoners rely on. Second, California’s new 2011 Public Safety Realignment Plan—which s...

background: radiofrequency catheter ablation (rfca) has been introduced as the treatment of choice for supraventricular tachycardia. the aim of this study was to evaluate the success rate as well as procedural and in-hospital complications of rfca for the treatment of atrioventricular nodal reentrant tachycardia (avnrt).   methods: between march 1995 and february 2009, 544 patients (75.9 % fema...

G. Francis and F. Hermens (2002) used computer simulations to claim that many current models of metacontrast masking can account for the findings of V. Di Lollo, J. T. Enns, and R. A. Rensink (2000). They also claimed that notions of reentrant processing are not necessary because all of V. Di Lollo et al.’s data can be explained by feed-forward models. The authors show that G. Francis and F. He...

The electrophysiology of antidromic reentry, a less common phenomenon than orthodromic reentry, remains a poorly understood aspect of the Wolff-Parkinson-White (WPW) syndrome. We used a pacing model of ventricular preexcitation in patients without WPW, so that electrophysiological events in the normal pathway during atrial extrastimulation (A1-A2 technique) could be precisely delineated without...

INTRODUCTION Standard electrophysiologic techniques generally allow discrimination among mechanisms of paroxysmal supraventricular tachycardia. The purpose of this study was to determine whether the response of paroxysmal supraventricular tachycardia to atrial and ventricular overdrive pacing can help determine the tachycardia mechanism. METHODS AND RESULTS Fifty-three patients with paroxysma...