Heart rate variability in soccer players with mitral valve prolapse or benign arrhythmia

Abstract Numerous studies have reported increased cardiac vagal activity in well endurance-trained athletes. However, no clear data exist regarding the cardiac autonomic activity in athletes with common cardiovascular findings, such as mild mitral valve prolapse (MVP) and transient benign arrhythmias. Therefore, the purpose of this study was to investigate and compare the cardiac autonomic outflow by heart rate variability (HRV) analysis between soccer players with mild MVP and rhythm disorders and other athletes with transient benign arrhythmias but without any structural cardiac disease. Twenty Greek male soccer players with mild MVP (group A, aged 20.2±4.5 years), 20 players with benign cardiac rhythm and conduction disorders without structural cardiac disease (group B, aged 21.0±3.6 years) and 20 healthy age-matched sedentary men (group C) were examined. All subjects underwent clinical evaluation, resting electrocardiogram for QTc calculation, echocardiography and 24-h ambulatory Holter recordings for HRV analysis. The mean 24-h heart rate, the HRV index and the mean 24-h R-R interval were significantly increased in all athletes compared to controls (p<0.05). Moreover, group A presented significantly decreased HRV index compared to group B by 18.2% (p<0.05). Resting QTc was prolonged only in group B compared to groups A and C by 9.5% and 11.2%, respectively (p<0.05), whereas no significant difference was found between groups A and C. It is concluded that athletes with MVP present limited exercise-induced cardiac vagal predominance compared to those with benign arrhythmias and without any structural cardiac disease.