One-dimensional simulation of alternating conduction under hyperkalaemic conditions

Hyperkalaemic conditions belonged to one of changes brought by ischemia. Hyperkalaemia is identified as a major determinant of ventricular arrhythmias. One-dimensional fiber model of transmural cells was used to simulate regional hyperkalaemic conditions. We investigated the process of alternating conduction developing induced by hyperkalaemia. Hyperkalaemic region closer to Endo cells was more likely to cause 2:1 conduction blocks. Increased depolarization time and conduction delay were essential for blocks developing. The L-type calcium current (I
_CaL
) became too small to maintain the phase of depolarization every other beat during the process of conduction. Alternans associated with alternating conduction could be considered as a marker of acute regional ischemia/hyperkalaemia.