Prediction of arrhythmic risk in patients with mitral annular disjunction

Abstract

Mitral annular disjunction is a gap between the mitral ring and the ventricular myocardium, and is associated with mitral valve prolapse. A minority of these patients experience life-threatening ventricular arrhythmias, but the incidence of such arrhythmias is largely unknown and estimating risk is challenging. In the doctoral thesis “Prediction of arrhythmic risk in patients with mitral annular disjunction”, Dr. Eivind Westrum Aabel and colleagues assessed the incidence and explored possible risk markers of ventricular arrhythmias in patients with mitral annular disjunction. The three studies of this thesis describe the incidence rate of ventricular arrhythmias and describes possible predictors of increased arrhythmic risk in patients with mitral annular disjunction. The first study described the incidence of ventricular arrhythmia using continuous heart rhythm monitoring, and shows a high rate of first time ventricular arrhythmia and re-events. The second study assessed patients using cardiac magnetic resonance imaging and was the first study to describe the finding of concomitant right-sided annular disjunction. The third study described the prevalence of electrocardiogram features and reported that T-wave inversion was associated with prior ventricular arrhythmia and diffuse myocardial fibrosis. These observations improve our knowledge of risk stratification and provide clinicians caring for patients with mitral annular disjunction valuable information when evaluating the need for different follow-up strategies. External validation in larger prospective studies are important before fully implementing these observations in clinical practice.