Mitral Valve Prolapse with Syncope: Don't Judge the Book by its Cover!

A 33-year-old female with recurrent syncope episodes showed normal ECG and Holter results, but had mitral valve prolapse (MVP) with moderate mitral regurgitation (MR) on an echocardiogram. Cardiovascular magnetic resonance (CMR) revealed mitral annulus disjunction (MAD) with fibrosis. She received an implantable loop recorder (ILR). Several months later, she experienced a syncope event, which correlated with self-terminating polymorphic ventricular tachycardia (PMVT) preceded by narrow complex tachycardia, which was proven to be atrioventricular nodal reentrant tachycardia (AVNRT) in an electrophysiology study. Post-ablation, she had no recurrences of syncope. This case highlights the importance of ILR in avoiding unnecessary ICDs in MVP patients with syncope.