A novel RYR2 variant associated with catecholaminergic polymorphic ventricular tachycardia requiring extracorporeal cardiopulmonary resuscitation and complicated by cervical vascular injury: a case report

Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome that can cause sudden cardiac arrest. Its recognition after resuscitation may be obscured by troponin elevation and transient ventricular dysfunction, resembling fulminant myocarditis. Extracorporeal cardiopulmonary resuscitation (ECPR) can provide temporary circulatory support during refractory cardiac arrest; however, cervical cannulation carries a risk of vascular thrombosis and bleeding. We report a case of a child with ryanodine receptor 2 ( RYR2 )-associated CPVT, complicated by a compressive cervical haematoma after decannulation. Case presentation A 9-year-old boy with two previous syncopal episodes sustained a startle-triggered out-of-hospital cardiac arrest and developed recurrent polymorphic ventricular tachycardia after admission to the paediatric intensive care unit. Right cervical veno-arterial extracorporeal membrane oxygenation was established after continuous cardiopulmonary resuscitation without sustained return of spontaneous circulation, with an estimated resuscitation-to-flow interval of approximately 60 minutes. Serum troponin I was measured at 5.11 µg/L and left ventricular ejection fraction was 42–44%, prompting treatment for suspected diagnosis of fulminant myocarditis; the ejection fraction subsequently fell to 33%. Whole-exome sequencing identified a novel heterozygous RYR2 variant, c.11836G > A (p.Gly3946Ser), classified as pathogenic by the reporting laboratory according to ACMG/AMP criteria. The variant is absent from ClinVar, relevant population reference databases, and the published literature, and its identification, together with the patient’s characteristic clinical phenotype, supported the diagnosis of RYR2 -associated CPVT. During anticoagulation for cervical vascular thrombosis after decannulation, an enlarging haematoma with active extravasation and tracheal compression required surgical evacuation, carotid repair, jugular thrombectomy, and venorrhaphy. The child was discharged after 41 days with a signficant improvement ejection fraction of 67%, persistent internal jugular occlusion, and propranolol and aspirin therapy. Conclusions CPVT should be reconsidered after an adrenergic cardiac arrest, even when post-arrest findings suggest myocarditis. ECPR can provide temporary rescue support. A rare RYR2 variant detection may support the clinical diagnosis and intervention.