Effects of intermittent coronary sinus occlusion on experimental myocardial infarction and reperfusion hemorrhage

The effects of intermittent coronary sinus occlusion (ICSO) on the size of myocardial infarction and reperfusion hemorrhage was evaluated. In Protocol 1, 8 dogs with ICSO and 8 controls underwent 4h of occlusion of the left anterior descending coronary artery. The same number of dogs underwent 4h of occlusion followed by 1h reperfusion in Protocal 2. The ICSO was started 1h after the ligation and continued through the occlusion period. There was no difference between the ICSO and the control group in hemodynamics and regional myocardial blood flow using hydrogen clearance method. However, ICSO did accelerate the rate of decline in intramyocardial CO2 tension. The half life of CO2 tension was 256 +/- 106 min in the control group but 139 +/- 34 min in the ICSO group (p less than 0.01). Lactate extraction rate showed the improving tendency during ICSO period. The ICSO resulted in a 50% and 80% reduction on an average in the size of infarct and reperfusion hemorrhage, respectively. We conclude that ICSO has prospective effects on myocardial ischemia with promise for clinical application.