Antitachycardia pacing.

Patients who have attempted repair of congenital heart disease often develop bradycardia and tachycardias postoperatively. The two dysrhythmias each make treatment of the other more difficult. Pacing is the only modality that addresses both brady- and tachycardias, without adversely influencing the other. Most postoperative tachycardias are reentrant, and thus uniquely susceptible to overdrive pacing. Usually an atrial single lead system is used. The patients most commonly encountered are those with extensive atrial surgery, such as atrial septal defect (ASD) repair. Mustard and Senning repair of d-transposition, and the various types of Fontan operations. The results are excellent for ASD repair and postoperative transposition, but only fair for postoperative Fontan patients.