Electrophysiologic and pharmacologic characteristics of automatic ectopic atrial tachycardia.

Abstract

In 7 children 6 wk-9 yr of age the diagnosis of chronic atrial tachycardia due to an automatic ectopic focus was established by clinical course, by the recording of intracardiac electrograms and by atrial stimulation during cardiac catheterization. Overdrive atrial pacing and programmed premature atrial stimulation failed to influence the tachycardia. Digoxin reeestablished sinus rhythm in 1 patient, while it slowed the tachycardia rate slightly in 6. Propranolol with digoxin was effective in restoring sinus rhythm in 3 cases, ineffective in 1 and slowed the rate in 2. Diphenylhydantoin was effective in 1 or 2 patients in whom it was used. Reserpine restored sinus rhythm in the 1 patient to whom it was given. Although automatic ectopic atrial tachycardias are difficult to manage, an aggressive diagnostic and pharmacologic program results in a high degree of control.