Mitral regurgitation (MR) caused by mitral valve prolapse (MVP) is a common clinical condition that affects approximately 2% of the population [1]. Patients with chronic primary MR develop cardiac remodeling due to persistent volume overload, increased cardiac diameter, eccentric ventricular hypertrophy, and eventually left ventricular (LV) dysfunction. Studies have shown that cardiac remodeling and myocardial fibrosis may develop in association with chronic MR [3,4]. Surgical mitral valve repair (MVR) is the recommended treatment for severeprimary MR. Preoperative LV ejection fraction (PreLVEF) and preoperative LV end-systolic diameter (PreESD) are known predictors for postoperative LV dysfunction after mitral valve repair [5].

Fragmented QRS complex (fQRS) includes the RSR’ pattern within QRS of different morphology detected in 12‑lead electrocardiography (ECG). fQRS is associated with myocardial scar, myocardial fibrosis, structural heart anomalies, ventricular dysrhythmia, and coronary artery disease [[6], [7], [8], [9], [10]].

In the present study, we aimed to evaluate the relationship between fQRS in preoperative ECGs and postoperative LV dysfunction that develop after MVR in patients with severeprimary MR due to MVP.