Cardiac Structural and Functional Changes in Competitive Amateur Cyclists

PURPOSE: To assess cardiac structural and functional changes induced by competitive amateur cycling. METHODS: Fifty-one young competitive amateur male cyclists and 47 age- and gender-matched control subjects underwent complex transthoracic echocardiographic examination focused on the detailed assessment of cardiac size and function, especially of the left ventricle (LV). Subsequently, spiroergometry was performed in all study participants and its results were compared to echocardiographic data. RESULTS: Higher left ventricular mass indexes due to the greater LV wall thickness and LV end-diastolic diameter were found in amateur cyclists as compared to control subjects. There were no differences with regard to the LV systolic function parameters. However, significantly better indices of LV diastolic function were present in cyclists. A significant correlation between maximal oxygen pulse and LV mass index/height(2.7), LV diastolic parameters and right ventricular size was noted. CONCLUSIONS: Amateur competitive cycling leads to considerable LV structural and functional changes. The increases in LV wall thickness and cavity size together with supranormal diastolic properties are key characteristics of this LV remodeling. As well, LV mass, diastolic function, and RV size are predictors of exercise capacity, indicating an important involvement of these elements in improving cardiac function with endurance training.