Treatment of Chronic Ventricular Dysrhythmias in the Young

The decision to treat chronic ventricular dysrhythmias in o young patient is based upon the potential for eJectrophysioIogic or hemodynamic instability. We have treated 51 young patients (mean age 13.4 years; range 1 week to 30 years) with chronic ventricular dysrhythmias according to the following guidelines: multiform premature ventricular contractions (PVCs), couplets and ventricular tachycardia were treated in all patients; frequent uniform PVCs were treated in patients with an abnormal heart. All patients were admitted to the hospital and continuous 24‐hour electrocardiograms (ECGs) were performed. Drug serum concentrations were measured every six hours. A drug was considered “effective” if there were less than 10 uniform PVCs per hour. Drug dosages were increased until clinical signs of mild toxicity developed or the serum concentration was above the therapeutic range. Drug treatment was begun in each patient with phenytoin: 32 received an oral loading dose and 19 an intravenous loading dose. If this was ineffective, other drugs were added or substituted: propranolol, quinidine sulfate and disopyra‐mide. Patients were divided into three groups according to their hemodynamics. The ages and types of ventricular dysrhythmias were similar for the three groups. Group I had 25 patients with severely abnormal hemodynamics; drugs were effective in 92%. Group II had 22 patients with moderately abnormal hemodynamics; drugs were effective in 68%. Group III had four patients with normal hemodynamics; drugs were effective in 50%. Phenytoin was the most effective drug in 39/51 (76%) followed by propranolol in 3/7 (43%) and quinidine in 1/7 (14%). We conclude: (1) chronic ventricular dysrhythmias can be controlled in 76% of children with standard drug regimens. (2) The response to drugs was significantly related to hemodynamic status: the most effective control was in patients with severely abnormal hemodynamics and the least effective was in patients with a normal heart. (3) Phenytoin is the drug of choice for children with ventricular dysrhythmias, especially those with abnormal hemodynamics. (PACE, Vol. 4, November‐December, 1981)