Surgical problems with multiple accessory pathways of atrioventricular conduction.

Thirty-six accessory pathways of atrioventricular conduction of the Kent type were found in 17 patients in a series of 161 patients subjected to direct operation for arrhythmias caused by the pathways. Careful preoperative studies detected the multiple pathways in 11 patients. In four patients, the additional pathways were found at operation, and in two patients they were found after operation. The operation successfully interrupted 32 of the 36 pathways. Multiple pathways must be sought for in all patients who are operated upon for arrhythmias caused by accessory pathways.