Ventricular arrhythmias during exercise in patients with mitral valve prolapse

Mitral valve prolapse (MVP) can be associated with ventricular arrhythmias (VA), but little is known about the relationship between VA and exercise in these patients. The aim of this study was to assess the occurrence and severity of VA during exercise tests in patients with MVP, and to explore the association between VA during exercise and the occurrence of arrhythmic events during follow-up.

In this multicentre study, 375 patients with MVP (58 (48-69) years, 53% male) who underwent a clinically indicated exercise test were included. Severity of VA during exercise was defined as: (1) no VA, (2) minor VA (premature ventricular contractions ≥5% or non-sustained ventricular tachycardia (nsVT) <120 beats per minute) and (3) major VA (nsVTs ≥120 beats per minute).

During exercise test, 242 (65%) patients showed no VA, 88 (24%) minor VA and 45 (12%) major VA. Patients with minor and major VAs showed more often bileaflet prolapse and mitral annular disjunction (MAD) than patients with no VA (p<0.001). Over a median follow-up of 101 months (IQR 58-138 months), 35 patients (9%) developed a severe arrhythmic event, defined as sustained VA or ventricular fibrillation, implantation of an implantable cardioverter-defibrillator and VA ablation. At the Kaplan-Meier curve analysis, patients with major VA showed the worst arrhythmic event-free survival (log-rank p<0.001). On multivariable analysis, left ventricular end-systolic diameter, MAD and VA severity during exercise were independently associated with this outcome.

In patients with MVP, the occurrence of VA during exercise is associated with more advanced mitral valve abnormalities, including MAD, and with higher rates of severe arrhythmic events during follow-up. Performing an exercise test, combined with the clinical and echocardiographic assessments, may therefore offer important complementary information useful for patient management.