Propafenone hydrochloride, a class 1C antiarrhythmic agent, combines
sodium channel-blocking effects with beta-blocking capacities and a weak
calcium antagonism. The
drug exerts marked electrophysiologic effects on
accessory atrioventricular pathways. In patients with
atrioventricular nodal reentry tachycardia,
propafenone is able to block conduction in the fast conducting pathway. In addition,
propafenone is very effective in young patients with
supraventricular tachycardia based on enhanced abnormal automaticity. In pediatric patients, left ventricular performance remains unimpaired. Proarrhythmic events have been noted in children only occasionally. In accordance with the electrophysiologic profile, intravenous and oral
propafenone is an effective agent for treatment of
supraventricular tachycardia based on a reentry mechanism and due to abnormal automaticity (i.e.,
supraventricular tachycardia based on an
accessory atrioventricular pathway,
atrioventricular nodal reentry tachycardia,
junctional ectopic tachycardia, and
atrial ectopic tachycardia). In children with ventricular dysrhythmias, efficacy seems to be related to the underlying cardiac diagnosis.
Propafenone is well tolerated in the majority of young patients. Incidence of proarrhythmic events seems to be lower with
propafenone than with other class 1C agents. However, the risk of these serious adverse events should be taken into account when
therapy with
propafenone is considered, particularly in patients with structural
heart disease.