[Myocardial contractility in different methods of Cardioplegia. An experimental study (author's transl)].

In 22 mongrel dogs the protective effect on the myocardium of Bretschneider- and Kirsch-Cardioplegia (90 minutes of cardiac arrest) was studied and compared with ischemic arrest (45 minutes at hypothermia of 30 degrees C). Myocardial contractility was evaluated by the following indices of contractility: t--dp/dt max., Krayenbühl-Index of contractility and max. Vce. Depression of contractility of 40 % was observed after ischemic arrest and Kirsch-Cardioplegia, whereas in Bretschneider-Cardioplegia depression was only 7 %. Forty-five minutes after reperfusion contractility had returned to normal in the last group. It is concluded that Bretschneider-Cardioplegia results in little reduction of postischemic contractility, and has a good protective effect on the myocardium.