Effects of Aortocoronary Bypass Surgery on Myocardial Blood Flow
The effects on myocardial blood flow of aortocoronary by- pass surgery for twenty patients with ischemic heart disease and the influence of hand grip exercise were studied using 201T1 myocardial scintigraphy. 1. The ratio of preoperative myocardial blood flow to cardiac output was 4.41 % in the group of patients with angina pectoris and 4.33% in the group with a history of myocardial infarction. No significant increase was noted following the aortocoronary bypass surgery in both groups. After preoperative exercise loading, a significant increase in the ratio from 4.33% to 6.47% was noted only in the group with a history of myocardial infarction (p<0.05). 2. The cardiac output did not increase in either group in response to preoperative exercise, however significant increase of that was seen on exercise after the operation in both groups. 3. There was no significant increase in myocardial blood flow following the operation. After the postoperative exercise, however, a significant increase was obtained, from 253 ml to 357 ml in the group with angina pectoris and from 199 ml to 334 ml in the group with a history of myocardial infarction.