Effect of coronary sinus occlusion on coronary circulation and hemodynamics 1. effect of coronary sinus occlusion on coronary hemodynamics and incidence of ventricular fibrillation during acute myo cardial ischemia in dogs
Nishiyama, O.
Okayama Igakkai Zasshi 96(1-2): 87-99
1984
ISSN/ISBN: 0030-1558 Accession: 005229491
The effect of coronary sinus (CS) occlusion produced with a specially designed balloon catheter on coronary hemodynamics and ischemia-induced ventricular fibrillation was studied in anesthetized open-chest dogs. Heart rate (HR), aortic blood pressure (BP), left ventricular max dp/dt, coronary blood flow (CBF) and cardiac output decreased slightly with coronary sinus occlusion, while left ventricular end-diastolic pressure was not affected. These changes were attenuated but did not disappear by pre-treatment with atropine. These changes were apparently, in part, direct effects of venous congestion in the ventricular wall. CBF decreased in the diastolic, but increased in the systolic phase. Coronary sinus pressure (CSP) markedly increased especially in systole after CS occlusion, resulting in a pressure pattern resembling the left ventricular pressure pattern. The CSP exceeded the left ventricular pressure in diastolic phase. Peak flow, reactive hyperemia flow and repayment after a brief coronary artery occlusion were all decreased. Myocardial O2 extraction increased by .apprx. 9% and the increase correlated well with the elevation of mean CSP. When the left anterior descending coronary artery was occluded, CS occlusion increased retrograde pressure from 22 .+-. 4 mm Hg to 33 .+-. 7 mm Hg, and the incidence of ventricular fibrillation was decreased. Washout of the metabolites by retrograde flow from the ischemic myocardium would seem to be responsible for this reduction of ventricular fibrillation.