Changes in the QRS complex after aortic valve replacement.

The electrocardiograms of 50 patients after isolated aortic valve replacement were examined. Two main types of postoperative QRS changes were found. In I3 patients intraventricular conduction defects developed, predominantly in theform ofa left anterior hemiblock as an isolated lesion or combined with other focal blocks. The other prominent finding was the appearance of abnormal Q waves suggesting inferior wall infarction in 8 patients, and anterior wall infarction in one. Intraventricular conduction defects were interpreted as evidence of involvement of the conducting system during removal of the abnormal valve, whereas uneven myocardial blood flow during coronary perfusion was thought to be responsiblefor the appearance of abnormal Q waves. The clinical importance of these findings is discussed.