We studied the individual and combined effects of extracellular acidosis and increases in extracellular potassium on action potential characteristics and conduction in order to gain a better understanding of the effects of acute ischemia. At each level of potassium between 2.7 and 17 mm, acidosis induced by increasing Pco2 (respiratory acidosis) and by decreasing HCO3- (metabolic acidosis) decr...

Altered gap junctional coupling potentiates slow conduction and arrhythmias. To better understand how heterogeneous connexin expression affects conduction at the cellular scale, we investigated conduction in tissue consisting of two cardiomyocyte populations expressing different connexin levels. Conduction was mapped using microelectrode arrays in cultured strands of foetal murine ventricular m...

Conduction velocity in the heart is dependent on two main factors: intercellular electrical coupling and cellular electrical excitability. There is significant redundancy, “conduction reserve”, in these parameters such that significant reduction in the conduction velocity of the action potential requires either a large change in one of these parameters or combined changes in both. We have used ...

BACKGROUND During development, AV conduction switches from base-to-apex to apex-to-base conduction after emergence of the conduction system. We hypothesize that after this transition, the bulk of the AV ring, although no longer required for AV conduction, remains transiently able to conduct, providing a potential arrhythmia substrate. We studied AV conduction during this transition and its sens...

background: ventriculoatrial (va) conduction has an important role in the initiation and maintenance of some arrhythmias. the aim of this study was to evaluate whether clinical and electrophysiological parameters of atrioventricular (av) conduction can predict va conduction. methods: detailed demographic, electrocardiographic, and echocardiographic data were recorded in 54 consecutive patients ...