Role of Cardiac Magnetic Resonance (CMR) as a Diagnostic and Risk Stratification Tool for a Patient With Arrhythmic Mitral Valve Complex Phenotype and Tricuspid Annular Disjunction (TAD)

Arrhythmogenic mitral valve disease (AMVD) is a newly established entity that carries a high risk of developing ventricular arrhythmia ranging from premature ventricular contraction to sudden cardiac death. Therefore, there is an urgent need for risk prediction and stratification by using different imaging modalities. A 77-year-old patient presented with a syncopal episode. Physical examination was unremarkable. Resting electrocardiogram (ECG) was normal. Echocardiography showed mild systolic dysfunction and mild aortic stenosis. Seven days of Holter monitor recording demonstrated frequent episodes of polymorphic ventricular contraction and one episode of sinus bradycardia. Therefore, the patient was scheduled for cardiac magnetic resonance (CMR) which was successful in revealing the etiology of the presentation. Biannuli disjunction and mitral valve prolapse could be clearly visualized in our CMR study. Consequently, the patient was referred for an urgent clinical consultation by the electrophysiology heart team and implantable loop recorder. A review of the six-week recording showed further episodes of narrow complex tachycardia with rates up to 222 beats per minute (bpm) associated with one episode of pre-syncope. He was prescribed bisoprolol and scheduled for regular follow-up at the arrhythmia clinic. In our report, we present a case of AMVD when the definite diagnosis could not be revealed by using the echocardiography modality alone. However, CMR has been proven successful in establishing a diagnosis and unveiling the etiology of the presentation.