The reduction of ectopic burden after mitral valve surgery in patients with mitral annular disjunction.

Objectives: Mitral annular disjunction is a recognized risk factor for malignant ventricular arrhythmias in patients with mitral valve prolapse. This study aimed to evaluate the impact of mitral valve surgery on the burden of supraventricular and ventricular ectopic activity in patients with mitral annular disjunction.

Methods: Data from 32 patients who underwent mitral valve surgery between 2017 and 2024 were retrospectively analysed. The primary end-point was the change in the burden of supraventricular and ventricular ectopy following surgery. The secondary end-point was to assess whether this change differed according to the extent of the mitral annular disjunction distance.

Results: The mean age of the patients was 38.8 ± 14 years, and 53.1% were female. The vast majority (96.9%) underwent successful mitral valve repair. The mean cardiopulmonary bypass and aortic cross-clamp times were 133.3 ± 38 min and 95.8 ± 32 min, respectively. Postoperatively, the mean burden of supraventricular ectopy decreased from 13.8% to 3.7%, and ventricular ectopy burden decreased from 7.1% to 2.1%. Among patients with a mitral annular disjunction distance ≥8.5 mm, both supraventricular and ventricular ectopic activity significantly declined. In contrast, for those with a mitral annular disjunction distance <8.5 mm, a significant reduction was observed only in ventricular ectopy, with no statistically significant change in supraventricular ectopy.

Conclusions: Mitral valve surgery is associated with a substantial reduction in both supraventricular and ventricular ectopic activity in patients with mitral annular disjunction. Furthermore, a mitral annular disjunction distance greater than 8.5 mm appears to be a predictor of a more pronounced reduction in arrhythmic burden following surgery.