Recruitment of stretch-activated channels, one of the mechanisms of mechano-electric feedback, has been shown to influence the stability of scroll waves, the waves that underlie reentrant arrhythmias. However, a comprehensive study to examine the effects of recruitment of stretch-activated channels with different reversal potentials and conductances on scroll wave stability has not been underta...

Fibrosis and altered gap junctional coupling are key features of ventricular remodelling and are associated with abnormal electrical impulse generation and propagation. Such abnormalities predispose to reentrant electrical activity in the heart. In the absence of tissue heterogeneity, high-frequency impulse generation can also induce dynamic electrical instabilities leading to reentrant arrhyth...

BACKGROUND Congenital Long QT syndrome (LQTS) is an arrhythmogenic disorder that causes syncope and sudden death. Although its genetic basis has become well-understood, the mechanisms whereby mutations translate to arrhythmia susceptibility in the in situ human heart have not been fully defined. We used noninvasive ECG imaging to map the cardiac electrophysiological substrate and examine whethe...

AIMS The site of successful ablation of the slow atrioventricular (AV) nodal pathway may be located in the posteroseptal or midseptal area. We have previously shown that the site of successful radiofrequency (RF) ablation of the slow pathway, rather than residual slow pathway conduction correlates with AV nodal re-entrant tachycardia (AVNRT) recurrences, with more recurrences noted in inferopos...

BACKGROUND The site of the reentrant circuit in atrioventricular (AV) junctional reentrant tachycardia has not been defined; in particular, the existence of a common pathway of AV nodal tissue above the reentrant circuit is controversial. METHODS AND RESULTS Two types of AV junctional reentrant tachycardia were induced in each of three patients at electrophysiological study. In one type of ta...

Our purpose was to characterize the excitable gap during atrioventricular nodal reentrant tachycardia (AVNRT) to elucidate the electrophysiologic substrate of this clinically familiar microreentrant arrhythmia. Accordingly, in 11 patients with classic slow-fast AVNRT (mean cycle length, 342 +/- 41 msec), a single ventricular extrastimulus (V2) was periodically delivered after a spontaneous tach...

Introduction Ablation failure is uncommon for typical slow–fast AV nodal reentrant tachycardia (AVNRT) and it is estimated that in o1% of cases, ablation in the left atrium is required to modify the circuit. We report a case of typical AVNRT refractory to medical therapy and standard ablation approaches, that ultimately required ablation from the left ventricle to achieve noninducibility and cl...

The epicardial border zone (EBZ) of canine infarcts has increased anisotropy because of transverse conduction slowing. It remains unknown whether changes in gap junctional conductance (Gj) accompany the increased anisotropy. Ventricular cell pairs were isolated from EBZ and normal hearts (NZ). Dual patch clamp was used to quantify Gj. At a transjunctional voltage (Vj) of +10 mV, side-to-side Gj...

Atrial fibrillation occurs spontaneously after bradycardia induced by acetylcholine infusion or vagal stimulation. To determine the mechanism of initiation of this tachyarrhythmia, we infused acetylcholine (5 ml, 10(-3.5) M) into Krebs-Henseleit-perfused isolated canine right atria (n = 10). Unipolar electrograms were recorded from 250 sites simultaneously during control rhythms, pacing (cycle ...

Objective The purpose of this study was to compare remote magnetic catheter navigation with manual navigation for the ablation of atrioventricular nodal reentry tachycardia (AVNRT). Methods From November 2007 to November 2009, 30 consecutive patients with AVNRT received radiofrequency ablation in the Institute of Geriatric Cardiology. Of them, 14 were treated with remote magnetic navigation (RM...