Catecholaminergic polymorphic ventricular tachycardia complicated by dilated cardiomyopathy: a case report

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a severe genetic arrhythmogenic disorder characterized by adrenergically induced ventricular tachycardia manifesting as stress-induced syncope and sudden cardiac death. While CPVT is not associated with dilated cardiomyopathy (DCM) in most cases, the combination of both disease entities poses a major diagnostic and therapeutic challenge. CASE SUMMARY: We present the case of a young woman with CPVT. The clinical course since childhood was characterized by repetitive episodes of exercise-induced ventricular arrhythmias and a brady-tachy syndrome due to rapid paroxysmal atrial fibrillation and sinus bradycardia. Medical treatment included propranolol and flecainide until echocardiography showed a dilated left ventricle with severely depressed ejection fraction when the patient was 32 years old. Cardiac magnetic resonance imaging revealed non-specific late gadolinium enhancement. Myocardial inflammation, however, was excluded by subsequent endomyocardial biopsy. Genetic analysis confirmed a mutation in the cardiac ryanodine receptor but no pathogenetic variant associated with DCM. Guideline-directed medical therapy for HFrEF was limited due to symptomatic hypotension. Over the next months, the patient developed progressive heart failure symptoms that were finally managed by heart transplantation. DISCUSSION: Management in patients with CPVT and DCM is challenging, as Class I antiarrhythmic drugs are not recommended in structural heart disease and prophylactic internal cardioverter-defibrillator implantation without adjuvant antiarrhythmic therapy can be detrimental. Regular echocardiographic screening for DCM is recommendable in patients with CPVT. A multidisciplinary team of heart failure specialists, electrophysiologists, geneticists, and imaging specialists is needed to collaborate in the delivery of clinical care.