Ventricular Function Recovery Unmasks Mitral Annular Disjunction After Pediatric Sudden Cardiac Arrest.

Mitral annular disjunction (MAD) is associated with ventricular arrhythmias and sudden cardiac arrest (SCA). Echocardiographic characterization of pediatric MAD-associated SCA remains limited. Among 35 patients aged <21 years with MAD (1/2023-12/2024), 4 had SCA (3 with idiopathic ventricular fibrillation and 1 with an implantable cardioverter-defibrillator shock following an episode of polymorphic ventricular tachycardia). All echocardiograms and clinical data were reviewed. Three patients had moderate-to-severe ventricular dysfunction following cardiac arrest. MAD was not identified on the postarrest echocardiogram in the setting of dysfunction but became apparent after functional recovery. One of the 4 patients had an echocardiogram before their arrest, which demonstrated MAD. All 4 patients continued to have MAD at follow-up. This suggests that in pediatric SCA, moderate-to-severe left ventricular dysfunction may mask MAD in the postarrest period. Serial imaging after functional recovery is important to identify MAD in these patients.