BACKGROUND Superior vena cava (SVC) is an infrequent yet an important source of atrial fibrillation. The clinical impact of ATP injection on arrhythmogenic SVC has not been evaluated. METHODS AND RESULTS A total of 43 patients (59±11 years; men, 32) who underwent ATP test for arrhythmogenic SVC after the electric isolation at either initial procedure or repeat procedure were included. Pulmona...

Spatiotemporal dynamics in cardiac tissue emerging from the coupling of individual cardiomyocytes underlie the heart's normal rhythm as well as undesired and possibly life-threatening arrhythmias. While single cells and their transmembrane currents have been studied extensively, systematically investigating spatiotemporal dynamics is complicated by the nontrivial relationship between single-cel...

Abstract Background Previous studies have quantified repolarization variability using time-domain, frequency-domain and nonlinear analysis in mouse hearts. Here, we investigated the relationship between these parameters ventricular arrhythmogenicity a hypokalaemia model of acquired long QT syndrome. Methods Left monophasic action potentials (MAPs) were recorded during right regular 8 Hz pacing ...

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic disease associated with malignant arrhythmias, typically developing at high heart rate (HR) and catecholamine states. Patients are often restricted from exercise. Cardiopulmonary exercise testing (CPET) used to diagnose monitor patients ensure HR-associated arrhythmias adequately blunted on beta blockers (BB). In addition...

Skeletal myoblasts are an attractive cell type for transplantation because they are autologous and resistant to ischemia. However, clinical trials of myoblast transplantation in heart failure have been plagued by ventricular tachyarrhythmias and sudden cardiac death. The pathogenesis of these arrhythmias is poorly understood, but may be related to the fact that skeletal muscle cells, unlike hea...

BACKGROUND Slow delayed-rectifier potassium current (IKs) channels, made of the pore-forming KCNQ1 and auxiliary KCNE1 subunits, play a key role in determining action potential duration (APD) in cardiac myocytes. The consequences of drug-induced KCNQ1 splice alteration remain unknown. OBJECTIVE To study the modulation of KCNQ1 alternative splicing by amiloride and the consequent changes in IK...