[Changes in myocardial tolerance to ischemia as a function of circulatory arrest mechanisms]

This study tries to specify the tolerance limit of heart to ischemia and has three parts. In the first one, the author considers the heart resistance in normothermy related to the circulatory arrest type, the anesthetic technique, existence or not or a ventricular fibrillation. Everybody is tody in agreement to admit that 35 to 45 minutes are the security limit of the cardiogenous circulatory stop. In the second part, conditions of cardiac tolerance to ischemia in hypothermy are foreseen. The security margin is here large, provided a nonagressive realization of the cooling. Lastly, the author reports the looseness of the biochimic, histochemic or histologic criteriums which permit an appreciation of the heart functional capacity, appreciation which still persist to be essentially clinical.