Abnormal left ventricular wall motion at mid-ejection in patients with coronary heart disease.

The degree of inward motion at mid-ejection was examined for seven segments on the silhouettes of left ventriculograms taken in the 30 degrees RAO projection in patients with normal coronary arteries. The pattern of wall motion described in these patients was used to distinguish abnormalities in mid-systolic wall motion. One or more abnormally contracting segments were found at mid-ejection of 27 of 42 patients with obstructive coronary artery disease and normal end-systolic wall motion. Of the 57 segments found in these patients, 41 or 72% corresponded to sites of significant coronary artery obstruction. Seven patients had electrocardiographic evidence of prior infarction. Following coronary graft surgery in eight patients improved motion was found in association with graft patency in seven priviously delayed segments and two new areas of delayed wall motion associated with nonpatent grafts and electrocardiographic changes of infarction appeared. We postulate that some of the myocardial fibers in late contracting segments have been injured or infarcted and are able to contract effectively only during the latter half of ejection when ventricular wall tension is reduced.