Ectopic atrial tachycardia in children

Background and purpose: Ectopic atrial tachycardia (EAT) is an unusual and potentially risky arrhythmia that can result ill left ventricular dysfuncti on if not properly managed. In adults, EAT is mainly caused by diseased atr ial myocardium and responds poorly to antiarrhythmic drugs. The characteris tics of EXT in children might be different from those in adults because of their immature myocardium and the different electrophysiologic characterist ics of their conduction tissue. We examined the natural history and treatme nt 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 wi th a diagnosis of EAT. Fifteen had healthy hearts, six had congenital heart disease, one hall myocarditis, one had bronchopulmonary dysplasia with 1 s evere pulmonary hypertension, and one had hypertrophic cardiomyopathy. Thir teen patients presented with congestive heart failure. Only four patients h ad symptoms of prodromal airway infection. The maximum atrial rare was 244 +/- 66 beats per minute. Atrioventricular block was documented at least onc e during tachycardia in 10 patients. Warm-up or cool-down phenomenon was se en at the initiation or termination of tachycardia in thirteen patients. Pr imary pharmacologic treatment was attempted in all patients. EAT was initia lly controlled in all patients using digoxin plus propranolol (18 patients) , propranolol only (4), or digoxin plus procainamide (2). EAT was controlle d using medication in 22 patients. Fifteen patients had sinus rhythm but di d not receive medication fur 39 +/- 25 months. Two patients died of uncontr olled 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 recu rring EAT, all of whom remained tachycardia-free after surgery, without pha rmacologic treatment. The spontaneous remission rate was 75% (18/24). Conclusion: EAT in children without under lying heart disease can be effect ively treated using antiarrhythmic drugs. Spontaneous resolution of EAT aft er 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.