Extracorporeal membrane oxygenation for refractory arrhythmia in a neonate carrying an SCN5A variant: a case report

BACKGROUND: Neonatal malignant arrhythmias refractory to conventional antiarrhythmic therapy are life-threatening and pose a major therapeutic challenge, particularly in premature infants. CASE PRESENTATION: We report a premature infant born at 36 + 2 weeks of gestation who developed ventricular tachycardia and cardiac arrest following resuscitation for perinatal asphyxia. As lidocaine and amiodarone failed to control the rhythm, veno‑arterial ECMO was initiated shortly thereafter. After ECMO support, the rhythm converted to sinus and cardiac function improved, allowing successful weaning. Electrocardiography subsequently revealed a prolonged QT interval, which responded to oral mexiletine. Whole‑exome sequencing identified a heterozygous SCN5A c.1960G > A (p.Glu654Lys) variant inherited from the father, classified as a variant of uncertain significance (VUS). CONCLUSIONS: This case suggests that this specific VUS may be a candidate pathogenic variant, and that early ECMO can be an effective salvage therapy when conventional drugs fail. Additionally, when genetic testing yields a VUS, the clinical phenotype and treatment response appear valuable for assessing pathogenicity in neonatal cases.