Treatment of Ventricular Arrhythmias in Children Without Structural Heart Disease With Class IC Agents as Guided by Invasive Electrophysiology Christopher L. Case, MD, and Paul C. Gillette, MD lthough the efficacy of classIC antiarrhythmic agents in the treatment of supraventricular and ventricular arrhythmias in adults has beenclearly demonstrated,serious proarrhythmic effects have been reported.’ These agentshavealsoproven useful in the pediatric population, but there is growing concern that similar proarrhythmic potential exists.2,3Recognizingthat thesedrugs, although very useful, may also be deadly, we have adopteda protocol at the Medical University of South Carolina that uses invasiveventricular stimulation after drug administration to help assessthe risk/benefit ratio of these agentsin the treatment of ventricular arrhythmias. Since mid-1987, all 23 children with ventricular arrhythmias treated with IC agentshave had invasive stimulation performed after drug administration to evaluate efficacy or proarrhythmia, or both. Ten of thesechildren with structurally normal hearts, treated solely with IC agents, were tested in the electrophysiology laboratory both before and after drug administration; data from these 10 patients were used in this investigation (Table I).
8 hours, with a similar gradual increase until efficacy was reached. The average encainide dose was 100 f 35 mg/m2. A therapeutic response was judged to be present if sustained ventricular tachycardia was abolished or premature ventricular contractions reduced to
8 hours, with a similar gradual increase until efficacy was reached. The average encainide dose was 100 f 35 mg/m2. A therapeutic response was judged to be present if sustained ventricular tachycardia was abolished or premature ventricular contractions reduced to
