Role of delayed intraaortic balloon pumping in treatment of experimental myocardial infarction.
Intraaortic balloon pumping improves coronary blood flow characteristics while simultaneously reducing myocardial oxygen demands by reducing aortic systolic pressure. Clinical application of intraaortic balloon pumping has largely been in the "high risk" patient (cardiogenic shock, postinfarction angina, left main coronary artery disease and unstable angina) for support during diagnostic studies or cardiac surgery, or both. In addition, there is some evidence that balloon pumping immediately after coronary occlusion reduces the size of experimentally induced myocardial infarcts. In this study, myocardial infarcts were produced by ligation of the left anterior descending coronary artery in 12 dogs, 6 of which were treated with balloon counterpulsation beginning 3 hours after coronary occlusion. All dogs were killed 8 hours after coronary ligation. Intraaortic balloon pumping resulted in the expected hemodynamic changes (decreased aortic systolic pressure, left ventricular end-diastolic pressure and heart rate and increased aortic peak diastolic pressure). In addition, there was a significant reduction in infarct size in the group with balloon pumping as determined with epicardial S-T segment mapping, myocardial imaging with technetium-99m-glucoheptonate and histochemical staining with nitroblue tetrazolium. These results suggest that even when instituted as long as 3 hours after coronary occlusion, intraaortic balloon pumping results in significant reduction in infarct size and, it might be speculated, the mortality and morbidity associated with acute myocardial infarction may also be decreased.
D000787:Angina Pectoris / Q000628:therapy; D000818:Animals; D001243:Assisted Circulation / Q000295:instrumentation; D001794:Blood Pressure; D003326:Coronary Circulation; D004285:Dogs; D004562:Electrocardiography; D006339:Heart Rate; D006439:Hemodynamics; D007423:Intra-Aortic Balloon Pumping / Q000295:instrumentation; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D010101:Oxygen Consumption; D012770:Shock, Cardiogenic / Q000628:therapy