Experimental and clinical study of the pre-excitation syndrome.

Ventricular pre-excitation was experimentally produced in mongrel dogs. Their ECG and epicardial maps were analyzed. Forty-two cases of W-P-W syndrome were operated on between 1969 and May, 1980. The relationship between ECG, particularly the delta wave and localization and meaning of pre-operative examinations such as vectorcardiography, echocardiography, body surface mapping, intracavitary potential study, and cardiac pacing, were presented and discussed. As an intraoperative study, epicardial mapping was indispensable and was the most accurate method in determining the ACP. Endocardial potential study was another meaningful method in certain cases. Detachment of the atrium from the ventricle with an incision along the annulus and at the opposite of the pre-excitation area resulted in complete correction in 32 out of 34 cases between 1973 and May, 1980. Six cases of multiple ACPs were also corrected, although 4 needed a second operation. Indications for surgery of the W-P-W syndrome should be extended further in view of the high success and safety rate of the surgery.