[The effects of the internal mammary artery-coronary artery bypass surgery: with special reference to improvement of the regional wall motion of the left ventricle].

The internal mammary artery (IMA) has been used extensively for coronary artery bypass grafting because of its excellent long-term patency recently. However, the flow capacity of the IMA has been discussed and previous studies showed that the IMA should be used in the grafting of small coronary arteries or those with limited run-off. In this paper, we studied the ejection fraction and regional wall motion of the left ventricle in 19 patients undergoing coronary revascularization with the IMA and the normal group without ischemic heart disease. Preoperative analysis of these data showed the values were below the those of normal group. After surgery, left ventricular ejection fraction and regional wall motion improved and there were no difference between two groups. Although the graft flow through the IMA has been discussed since Green's pioneer work, our observations suggest that the IMA flow meets the myocardial demand adequately in the postoperative period.