Brady-tachy syndrome in the postoperative patient: Evaluation and case management

As initially described, bradycardia-tachycardia (brady-tachy) syndrome was used to describe the occurrence of atrial tachycardia in patients with resting sinus bradycardia. More recently, pediatric cardiologists have used this term to describe electrocardiographic abnormalities in patients who have had extensive atrial surgery to repair structural congenital cardiac defects. Although not all of these patients are symptomatic, many have bradycardia; in some, tachycardia also occurs. It is thought that these electrophysiologic abnormalities are related to extensive scarring of the atrium, which results in areas of abnormal conduction. These areas of conduction delay permit reentry to occur, thereby establishing sustained tachycardia. Treatment of these rhythm abnormalities is difficult. Acute management of an episode of atrial tachycardia is best accomplished with transvenous or transesophageal atrial pacing or cardioversion. Prophylaxis against tachycardia recurrence with antiarrhythmic drug exacerbates abnormalities of sinus rate. Therefore, management of atrial tachycardia with antitachycardia pacemaker therapy is an attractive option, because it also provides backup bradycardia pacing should antiarrhythmic drug therapy be necessary. Many patients may be managed with antitachycardia pacing alone, but others may have multiple types of atrial tachycardias or potentially life-threatening atrioventricular conduction during an atrial tachycardia, and so be considered for pharmacologic or ablative therapy. The role of brady-tachy syndrome in sudden death in these surgical patients has not yet been determined.