The effect of acute coronary artery occlusion on subepicardial transmembrane potentials in the intact porcine heart.

摘要: Subepicardial transmembrane potentials were recorded from intact pig hearts to observe the changes induced by acute ischemia. Ischemia shortened action potential duration, and decreased its amplitude, upstroke velocity, resting potential. The cells unresponsive after 12 15 minutes of coronary artery occlusion, yet near normal could be restored flushing occluded with saline as late 40 occlusion. unipolar extracellular electrogram reflected unresponsiveness a monophasic Local refractory periods initially up 100 msec. Later, postrepolarization refractoriness occurred lengthened often in excess basic cycle length, thus resulting 2:1 responses. onset early ventricular arrhythmias coincided period alternation responses, especially when these got out phase different regions. Reperfusion frequently led fibrillation, was associated ...