[Left ventricular function a short time after myocardial revascularization surgery: radioisotope angiographic study].

The short-term effects after coronary bypass surgery on left ventricular function were studied in 65 patients with coronary artery disease. Each patient underwent gated radionuclide left ventriculography on the second-third day before and 5-7 days after coronary bypass surgery. After surgery, global ventricular ejection fraction had a significant increase, anteroseptal wall motion was unchanged, while apical motion and mainly inferoposterior motion were significantly increased. The most important improvement of inferoposterior motion was observed in 18 patients who had complete revascularization of the previously infarcted inferior segments, while in the 11 patients with incomplete revascularization of the same area, inferoposterior motion had a slight increase. There was a slightly significant direct linear correlation between size and direction of the anteroseptal and inferoposterior motion changes. The patients were divided in subgroups related to the site and number of obstructed coronary vessels as well as of implanted grafts; the computed parameters showed similar changes in all subgroups. After surgery, peak ejection rate showed an evident increase, and time to peak reciprocally shortened. Peak filling rate, which had reduced preoperative values, was found clearly improved, with a corresponding shortening of the time to peak; these results confirmed that diastolic ventricular damage was a reversible disturbance related to myocardial ischemia. In 8 of the 65 patients, 24 hours urinary catecholamine levels showed similar values at both pre and postoperative radionuclide controls. In conclusion, the radionuclide angiography showed an evident improvement of left ventricular function during a short period following surgery, suggesting a better myocardial perfusion after revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)