Cardiac function and autonomic cardiac function during a multi-stage cycling event: a brief report.

Introduction: Prolonged and repeated exercise performed during an ultra-endurance event can induce general and cardiac fatigue known as exercise-induced cardiac fatigue. Our objective was to find a possible correlation between the cardiac function and the autonomic cardiac function. Methods: During a multistage ultra-endurance event, a female well-trained cyclist underwent daily rest echocardiography and heart rate variability measurements to assess the cardiac function and the cardiac autonomic function. Results: The athlete completed 3,345 km at 65% of her maximum heart rate and 39% of her maximum aerobic power. A progressive improvement of the systolic function for both the left ventricle and the right ventricle was observed during the event. Discussion: Alterations were observed on the cardiac autonomic function with an imbalance between sympathetic and parasympathetic, but there was no sign of a significant correlation between the cardiac function and the autonomic cardiac function and no signs of cardiac fatigue either. Further analysis should be performed on a larger sample to confirm the obtained results.