The effects of excision of left ventricular scars on the electrocardiogram.

: The effects of resection of post-ischemic ventricular scars on the electrocardiogram have been studied in 29 patients. No change occurred in atrial rhythm, P wave morphology, and A-V conduction. Fascicular blocks developed postoperatively in five patients. These were attributed to surgical trauma. Changes in mean frontal plane QRS axis were noted in 25 of 29 patients. There was no correlation between postoperative shifts in QRS axis and preoperative QRS axis, calculated scar size, or ventricular end-diastolic volume. No significant postoperative change was observed in Q waves or S-T segment deviation. It is concluded that electrocardiographic changes following scar resection occur randomly in a minority of patients. The presence of several unquantified factors makes it difficult to evaluate the post-resection electrocardiogram.