Architectural correlates of myocardial conduction: changes to the topography of cellular coupling, intracellular conductance, and action potential propagation with hypertrophy in Guinea-pig ventricular myocardium.

Architectural Correlates of Myocardial Conduction: Changes to the Topography of Cellular Coupling, Intracellular Conductance and Action Potential Propagation with Hypertrophy in Guinea-Pig Ventricular Myocardium Running title: Fry et al.; conduction velocity in ventricular hypertrophy

Effects of ischemia on discontinuous action potential conduction in hybrid pairs of ventricular cells.

BACKGROUND Acute ischemia often occurs in cardiac tissue that has prior injury, resulting in spatially inhomogeneous distributions of membrane properties and intercellular coupling. Changes in action potential conduction with ischemia, which can be associated with release of catecholamines, may be particularly important in tissue that has discontinuous conduction resulting from prior infarction...

Effect of Sodium Valproate on Ouabain-Induced Arrhythmia in Isolated Guinea-Pig Atria

Sodium valproate (SV), an antiepileptic drug has several mechanism of action. It inhibits voltage sensitive Na+ channels and reduces intracellular Na accumulation. These actions are similar to that of both phenytoin and carbamazepine. We have investigated the direct cardiac action of SV and its effects on ouabain-induced arrhythmia in isolated guinea-pig atria. The guinea-pig atrium was dissect...

Relationship between gap-junctional conductance and conduction velocity in mammalian myocardium.

BACKGROUND Gap junction resistivity, R(j), has been proposed as a key determinant of conduction velocity (CV). However, studies in connexin-gene knockout mice demonstrated significant CV slowing only with near-complete connexin deletion, and these findings led to the concept of a significant redundancy of myocardial gap junctions. We challenged this prevailing concept and addressed the hypothes...

Cellular uncoupling can unmask dispersion of action potential duration in ventricular myocardium. A computer modeling study.

Although slow conduction is a requirement for the preparation of sustained reentry, it alone is not sufficient for the initiation of reentry. Additionally, unidirectional block and recovery of excitability distal to the site of block must occur. Thus, a comprehensive description of the electrophysiological determinants of reentry must explain both slow conduction and unidirectional block. Altho...