Electrophysiologic effects of partial coronary occlusion and reperfusion.

Abstract Electrophysiologic changes caused by partial coronary occlusion have not previously been examined. In nine dogs, refractory periods and conduction times were determined using the extrastimulus method after a 50 percent reduction in coronary blood flow. In another five dogs, ventricular automaticity was studied after the production of complete heart block. After 5 minutes of partial coronary occlusion the refractory period in the ischemic zone shortened from 164.6 ± 4.2 (mean ± standard error of the mean) to 149.6 ± 5.8 msec ( P P