AbstractOBJECTIVESAim of this study was to evaluate arrhythmic burden of patients with Barlow’s disease and significant mitral regurgitation (MR) and assess the impact of mitral repair on ventricular arrhythmias (VA) in this group of subjects.METHODSWe prospectively included 88 consecutive patients with Barlow’s disease referred to our Institution from February 2021 to May 2022. All enrolled patients underwent 24-h Holter monitoring before surgery. Sixty-three of them completed 3 months echocardiographic and Holter follow-up. Significant arrhythmic burden was defined as ≥1% premature ventricular beats/24 h or at least one episode of non-sustained ventricular tachycardia (VT), VT or ventricular fibrillation.RESULTSAt baseline, 29 patients (33%) were arrhythmogenic (AR), while 59 (67%) were not [non-arrhythmogenic (NAR)]. AR subjects tended to be more often females with history of palpitations. Sixty-three patients completed 3-months follow-up. Twenty of them (31.7%) were AR at baseline and 43 (68.3%) were not. Among AR patients, 9 (45%) remained AR after mitral surgery, while 11 (55%) became NAR. Considering NAR subjects at baseline, after mitral valve repair 8 (18.6%) evolved into AR, while 35 (81.4%) remained NAR. A higher prevalence of pre-operative MAD was found among patients experiencing VA reduction if compared with patients who remained arrhythmogenic (63.6% vs 11.1%,P= 0.028).CONCLUSIONSIn our experience, one-third of Barlow’s patients referred for mitral surgery showed a significant arrhythmic burden. Almost half of the subjects arrhythmogenic at baseline were free from significant VA after mitral repair. However, a minority (18.6%) of subjects without arrhythmic burden at baseline experienced significant VA at follow-up.