Coronary Collateral Circulation in Coronary Occlusion

　The effect of coronary occlusion on the coro-nary collateral circulation has been studied in rested and exercised dogs.

　The ligation of the left coronary anterior descending artery was performed on dogs. They were divided into two groups, one group kept at rest for 1 to 10 weeks, the other group kept at rest for one week and then exercised for over one to 4 weeks. All animals in the rested group after 1 to 10 weeks and in the exercised group after 5 weeks, were measured for the critical value of the coronary blood flow which showed ST devia-tion on the electrocardiogram.