Significance of new Q waves after aortocoronary bypass surgery. Correlation with changes in ventricular wall motion.

From June 1969 to December 1974, 142 patients underwent aortocoronary bypass surgery at the Veterans Administration Hospital, San Francisco. Seventeen patients developed new Q waves; two of four deaths in the hospital occurred among these 17 patients. Preoperative and postoperative catheterization data were available for analysis in 12 of the 15 surviving patients. Longitudinal, transverse, and hemiaxial segmental analysis of preoperative and postoperative single plane, 30 degrees right anterior oblique left ventriculograms revealed deterioration in wall motion in all 12 patients. The deterioration corresponded to the area on the electrocardiogram where the new Q waves appeared. In ten of 12 patients, ejection fraction also deteriorated. Twenty-six of 29 grafts were patent. New Q waves after aortocoronary bypass surgery correlate well with the appearance of localized abnormalities in wall motion. We found no evidence that perioperative appearance of Q waves was not due to new perioperative myocardial infarction.