'Pulsatile' left atrial-femoral artery bypass. A new method of preventing extension of myocardial infarction.

A left atrial-femoral artery (LA-FA) bypass system was designed to deliver synchronous pulsatile blood flow. We compared it with nonpulsatile LA-FA bypass in its effectiveness to limit infarct extension after ligation of the left anterior descending coronary artery at its origin in 35 dogs. Nonpulsatile LA-FA bypass resulted in a 70% reduction in the size of infarct. The addition of synchronous diastolic counterpulsation (P-LA-FA) further reduced the size of infarct, when compared with that in controls (95%) or animals that underwent LA-FA bypass (83%). Both LA-FA and P-LA-FA bypasses limited infarct extension and reduced mortality after acute coronary occlusion through effective unloading of the left ventricle. The addition of diastolic counterpulsation to LA-FA bypass led to further significant infarct reduction, when compared with LA-FA bypass alone. These effects were most likely secondary to improvements in myocardial blood flow distribution.