Ectopic atrial tachycardia in children.

BACKGROUND AND PURPOSE Ectopic atrial tachycardia (EAT) is an unusual and potentially risky arrhythmia that can result in left ventricular dysfunction if not properly managed. In adults, EAT is mainly caused by diseased atrial myocardium and responds poorly to antiarrhythmic drugs. The characteristics of EAT in children might be different from those in adults because of their immature myocardium and the different electrophysiologic characteristics of their conduction tissue. We examined the natural history and treatment of EAT in children. METHODS AND RESULTS From June 1990 through June 1999, 24 children (8 girls and 16 boys; median age 4 mo [1 d-10 yr]) were admitted to our hospital with a diagnosis of EAT. Fifteen had healthy hearts, six had congenital heart disease, one had myocarditis, one had bronchopulmonary dysplasia with severe pulmonary hypertension, and one had hypertrophic cardiomyopathy. Thirteen patients presented with congestive heart failure. Only four patients had symptoms of prodromal airway infection. The maximum atrial rate was 244 +/- 66 beats per minute. Atrioventricular block was documented at least once during tachycardia in 10 patients. Warm-up or cool-down phenomenon was seen at the initiation or termination of tachycardia in thirteen patients. Primary pharmacologic treatment was attempted in all patients. EAT was initially controlled in all patients using digoxin plus propranolol (18 patients), propranolol only (4), or digoxin plus procainamide (2). EAT was controlled using medication in 22 patients. Fifteen patients had sinus rhythm but did not receive medication for 39 +/- 25 months. Two patients died of uncontrolled arrhythmia, and two of underlying disease. Recurrence was seen within 3 months after initial therapy in five patients. Surgery was performed to correct the underlying heart disease in three patients with frequently recurring EAT, all of whom remained tachycardia-free after surgery, without pharmacologic treatment. The spontaneous remission rate was 75% (18/24). CONCLUSION EAT in children without underlying heart disease can be effectively treated using antiarrhythmic drugs. Spontaneous resolution of EAT after medication in children was frequent (75%) in this series. The results of this study suggest that a step-wise approach using digoxin, a beta-blocker, and a class I antiarrhythmic drug may be the most effective treatment for EAT.