[Improved protection of the myocardium with a combination of intra-aortic balloon counter-pulsation and aimed substrate administration in acute myocardial infarct--a comparative study].

Abstract

In comparative studies in 36 mongrel dogs it was tried to find out how far intraaortic balloon pumping (IABP) applied solely and in combination with glucose-insulin-potassium (GIK) might influence the degree of acute myocardial ischemia. The ischemia lasted 3 hours. After 60 min myocardial ischemia IABP, the isolated GIK infusion, or the combination of IABP plus GIK were used. The directed GIK application into the aortic root was carried out by electronic triggering during the diastolic augmentation via a precoronary catheter. In the ischemic and in the non-ischemic myocardium of the left ventricle, ATP, creatine phosphate, and lactate were determined. Electronmicroscopical studies were carried out qualitatively as well as quantitatively. The isolated use of IABP suggested no protection of the energy-rich phosphates. The most significant morphological changes were found when exclusively the coronary ligature was applied and when only IABP was used, respectively. The best protective effect was achieved by our technique of the triggered GIK infusion via the precoronary catheter in combination with IABP. The ATP value (n mol/mg w.w.) in the ischemic area was 3.06 and in the non-ischemic one 4.96 in comparison to 1.96 and 3.99, respectively, in the control group. The creatine phosphate (n mol/mg w.w.) was 4.18 in the ischemic and 9.38 in the non-ischemic area in contrast to 2.36 and 6.99, respectively, in the control group. The technique of the triggered drug supply in combination with IABP offers the following advantages: --additive summation of IABP and substrate supply directed to the myocardium --high drug concentration in the myocardium --smaller drug load of the whole organism --clinical use of instable substances.