[Effect of various reperfusion regimens on the recovery of myocardial contractile function after total ischemia].

Isolated guinea pig hearts were subjected to 25-min total ischemia at 37 degrees C followed by 30-min reperfusion. The product of the left ventricular isovolumic systolic pressure and heart rate representing the cardiac work index was restored to 33 +/- 5% of initial value and diastolic pressure (DP) remained substantially elevated by 47 +/- 9 mm Hg if reperfusion was resumed with initial rate 10 ml/min. The gradual restoration of perfusion rate initiating from 2 or 4 ml/min was performed in other series, and was associated with slower but higher recovery of cardiac work and lower DP by the end of reperfusion. The similar result was observed when reperfusion was resumed with initial rate but a modified solution was used for first 5 min. In which Ca++ content was reduced while K+ and Mg++ elevated. In this case final recovery of cardiac work was 59 +/- 2% and DP completely returned to initial level. It is suggested that optimal reperfusion mode should be associated with slower work recovery.