Abstract
The major causes of death following acute myocardial infarction (AMI) are cardiogenic shock and arrhythmia. The number of rhythm death has been obviously decreased with the development of coronary care unit. To decrease the mortality rate of the patients with cardiogenic shock due to AMI, IABP has been widely, employed for thore severely ill patients. In this study, IABP was attempted in 94 mongrel dogs with cardiogenic shock due to AMI which was produced by multiple ligation of the coronary arteries. The effects of IABP on hemodynamics after AMI by using three types of balloon catheter (single, double, triple balloon) were also studied. The effects of IABP on hemodynamics resulted in an increase in coronary blood flow, cardiac output and diastolic pressure. A decrease in left ventricular pressure and end-diastolic pressure of the left ventricle was simultaneously observed as systolic unloading. A significant improvement was found in the proximal and distal portion of the balloon by using single or triple balloon. On the other hand, a marked improvement in hemodynamics was seen in the proximal portion of the balloon by using a double balloon. Triple balloon is indicated for the patients in whom IABP must be utilized for long term period. In clinical cases, balloon volume of 20ml was convenient for the patient with body weight less than 50kg. 30ml for the patients more than 50kg. However, suitable size of balloon must be developed for the Japanese people in the near future.
