Coronary blood flow and myocardial metabolism during reperfusion after hypothermic cardioplegia in the dog.
There have been many studies of reperfusion injury after normothermic ischemia. However, there have been few clinically relevant studies on the nature and time course of recovery of the myocardium during reperfusion after hypothermic cardioplegia. We studied reperfusion in the isolated dog heart supported by another dog. After 2 h of cardioplegic arrest at 20 degrees C, 11 normal hearts were reperfused for 30 min at optimal coronary pressures (60-100 mm Hg mean). The following events occurred: rapid rewarming, a transient hyperemia followed by a rapid return of both coronary blood flow and myocardial oxygen consumption to normal, washout of lactate, recovery of contractility and a slight decline in ATP. Most of these events occurred during the first 15 min of reperfusion. We concluded that, in normal hearts which are well protected during hypothermic cardioplegia, reperfusion at optimal coronary pressure results in recovery of the myocardium within 15 min, with the exception of recovery of ATP levels.
Rosenfeldt
F L
FL
Baker Medical Research Institute, Melbourne, Australia.
Rabinov
M
M
Newman
M
M
D000818:Animals; D003326:Coronary Circulation; D004285:Dogs; D006324:Heart Arrest, Induced; D007036:Hypothermia, Induced; D007773:Lactates / Q000097:blood; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption; D013318:Stroke Volume
D007773:Lactates