Anti-arrhythmia efficacy of propafenone in children. Apropos of 30 cases

Thirty children aged from 3 months to 20 years were treated with propafenone 250 to 650 mg/m2 divided into 2 to 4 daily doses, for a mean period of 14 months (range: 4 days to 5 years); 8 had chronic atrial tachycardia, 9 had junctional arrhythmia and 13 had ventricular arrhythmia. There were 17 good results (suppression of the arrhythmia), 7 fair results (good clinical effect but partial persistence of the arrhythmia) and 6 failures, either because the drug proved ineffective (3 cases) or on account of side-effects (3 cases). In the treatment of chronic atrial tachycardia propafenone seemed to be more effective than amiodarone in 3 cases and as effective as that drug in 2 cases. In junctional arrhythmia propafenone was certainly effective but unpredictably so (3 good results, 2 fair results, 4 failures). Among ventricular arrhythmias, ventricular tachycardia in bursts was the one which benefited most regularly from treatment with propafenone: the results in 8 patients were better than those obtained with other antiarrhythmic agents (class I drugs, beta-blockers, calcium antagonists); only amiodarone proved superior to propafenone in this type of arrhythmia. Despite a 27% incidence of side-effects, propafenone was generally well tolerated by the children, with no significant gastrointestinal disorders. No depressive effect on the myocardium was noted in 6 children with moderate heart failure well controlled by digitalis and diuretics. However, since overdosage may cause severe disorders of conduction with widened ventriculogram, we recommend regular ECG monitoring during the first 3 days of treatment at least: although there is little slowing down of sinus rate (12%) and little modification of the slow phase under treatment, serious toxicity is possible. Thus, propafenone is a drug that should be handled with caution, but it constitutes a major addition to the range of antiarrhythmic agents which can be used in paediatrics.