Clinical Characteristics, Outcomes, and Genetic Findings of Patients with Catecholaminergic Polymorphic Ventricular Tachycardia in Hong Kong

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare cardiac ion channelopathy. This was the first systematic review of published works on the clinical characteristics, outcomes, and genetic findings of patients with CPVT from Hong Kong. PubMed and Embase were searched electronically from their inception until February 2022. The Joanna Briggs Institute Critical Appraisal Checklist was used to critically appraise included studies. Studies written in English describing at least one patient with CPVT were included. Studies describing overlapping CPVT patients from previous reports were excluded. Two studies describing 17 patients with CPVT were included. All included studies were rated of acceptable quality. The largest case series evaluated 16 CPVT patients with a mean presentation age of 11 ± 4 years. Of these, 15 patients (93.8%) were symptomatic at initial presentation. Ten patients presented with both premature ventricular complexes (PVCs) and ventricular tachycardia/ventricular fibrillation (VT/VF), whereas one had PVCs without VT/VF. Among the 14 patients (87.5%) who underwent genetic testing, eight (57.1%) tested positive for the ryanodine receptor 2 (RyR2) gene. Over a mean follow-up duration of 116 ± 36 months, six patients (37.5%) had incident VT/VF. In a 5-year review of autopsy data retrieved from public mortuaries for 289 sudden cardiac death patients, one CPVT patient (0.03%) was identified. All patients with CPVT in Hong Kong presented at or below 19 years old, of whom a majority were initially symptomatic or had incident VT/VF events. Novel genetic variants in the RyR2 gene not reported beyond our locality were identified.