Can the QTc interval and T-wave morphology change intermittently in arrhythmogenic mitral valve prolapse? First paediatric case experience

Background: Mitral valve prolapse is typically considered a benign condition. However, a newly described repolarisation anomaly known as arrhythmogenic mitral valve prolapse syndrome is closely associated with repolarisation disturbances and can potentially lead to sudden cardiac death. Arrhythmogenic mitral valve prolapse syndrome is characterised by bileaflet mitral valve prolapse, mitral valve regurgitation, T-wave inversions in the inferolateral leads, and complex ventricular ectopy. Case Report: In this case, we present the diagnosis of arrhythmogenic mitral valve prolapse syndrome in a 16-year-old adolescent girl who experienced sudden cardiac arrest during exercise. Her electrocardiograms revealed intermittent QT/QTc prolongation. Interestingly, QT prolongation was always associated with T wave inversion in inferolateral leads. Heterozygous genomic changes were detected in the KCNH2 gene and the 25th exon of the ANK2 gene. These findings support the diagnosis of arrhythmogenic mitral valve prolapse syndrome in this patient. Conclusions: Since mitral valve prolapse is a common condition in the society, it is important to determine beforehand which ones are at risk of sudden death. As these boundaries are drawn better, underdiagnosis as well as overdiagnosis will be prevented.