Supraventricular Tachycardia in a Patient with Repaired Congenital Heart Disease

This case illustrates the difficulty in diagnosing atrial tachycardia in a patient who had a Mustard procedure for transposition of great arteries. Identification of atrial arrhythmias, even when they occur at physiologic ventricular rates, is important, because these patients are at risk for thrombus development and symptoms related to periods of a more rapid ventricular response. Another potential concern is that if the heart rate is elevated moderately during an unrecognized arrhythmia, the patient may develop a tachycardia-mediated cardiomyopathy over time. Patients with repaired congenital heart disease who develop postoperative tachyarrhythmias usually are treated aggressively to restore sinus rhythm. This is especially true in those who have residual intracardiac lesions or depressed myocardial function.