日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

Catecholaminergic polymorphic ventricular tachycardia can cause sudden cardiac death in children. Administration of β-blockers is the first-line therapy for catecholaminergic polymorphic ventricular tachycardia but does not completely prevent cardiac or fetal events. Similar to β-blockers, flecainide, a class I sodium channel blocker, has recently been reported to reduce the occurrence of exercise-induced ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia and prevent cardiac events. Changes in the electrocardiogram are proportional to the dosage of flecainide. However, no reports have investigated the association between exercise electrocardiography and blood flecainide concentrations in patients with catecholaminergic polymorphic ventricular tachycardia.

We report a case of catecholaminergic polymorphic ventricular tachycardia in an 8-year-old boy who was treated with β-blockers and flecainide. We used exercise electrocardiography to evaluate the treatment results and measured blood flecainide concentrations several times. We found that our patient required high doses of flecainide to achieve a sufficient therapeutic effect. Our case supports the requirement for exercise electrocardiography and repeated measurements of blood flecainide concentrations when treating children with catecholaminergic polymorphic ventricular tachycardia.