Background: Mitral valve prolapse (MVP) has been associated with sudden cardiac death. Mitral annulus disjunction (MAD) is an abnormal atrial displacement of the mitral valve leaflet hinge point, and has been proposed as a marker for sudden cardiac death in MVP patients. However, risk of ventricular arrhythmias in MAD itself, and in the absence of MVP, is poorly described.
Purpose: To describe the clinical presentation and prevalence of severe ventricular arrhythmias in patients with MAD with and without MVP.
Methods: We included consecutive patients from two hospitals with MAD defined as disjunction of >1 mm by study echocardiogram. We performed clinical examination and evaluated medical records for previous history of severe arrhythmic events, defined as aborted cardiac arrest or sustained ventricular tachycardia. Patients were excluded if they had non-mitral valvular disease, cardiomyopathies, channelopathies or obstructive coronary artery disease. We recorded the presence of MVP, measured MAD in the posterolateral wall (figure) in parasternal long-axis view, and measured left ventricular ejection fraction (EF).
Results: We included 115 patients (49±15 years, 60% female) with confirmed MAD. Severe arrhythmic events had occurred in 14 (12%) patients (n=10 aborted cardiac arrest, n=4 sustained ventricular tachycardia). Reported symptoms were palpitations (71%), presyncope (41%), chest pain (28%) and syncope (13%), with no difference between patients with or without severe arrhythmic events. Patients with severe arrhythmic events were younger (37±13 years vs. 51±14 years, p=0.001) and had lower EF (51±5% vs. 57±7%, p=0.002) compared to patients without events. MVP was evident in 63 (54%) patients and was less frequent in patients with severe arrhythmic events (4 (29%) vs. 59 (58%), p=0.04). In a multivariable logistic regression model including EF, age and MVP, lower EF (Adjusted OR 0.86 (95% CI, 0.77–0.97, p=0.01)) and lower age (Adjusted OR 0.94 (95% CI, 0.89–0.98, p=0.006) remained independent markers for severe arrhythmic events.
Conclusions: Patients with MAD frequently presented with arrhythmic symptoms, and 12% had experienced severe arrhythmic events. MVP was found in only half of the patients with MAD and was not associated with arrhythmic events, indicating MAD itself as an arrhythmogenic entity. In patients with MAD, lower age and EF were markers of severe arrhythmic events.