Right Ventricular Remodeling Following Intense and Prolonged Endurance Training

Despite the numerous cardiovascular benefits of exercise training, the exercise induced-right ventricular arrhythmogenic cardiomyopathy (ARVC) hypothesis has raised concerns in recent years about participating in intense and prolonged endurance exercise. Therefore, the present study aimed to investigate the structural, histological and functional remodeling of the right ventricle following intense and prolonged endurance training

Twenty 4-week-old male Wistar rats were randomly divided into control and training groups. The training protocol began with a progressive 4-week program with a frequency of three sessions per week for preparation, followed by a 12-week program with a frequency of five sessions per week for 60 minutes per week at a speed of 36 meters per minute (approximately 90% of maximum heart rate). The functional and structural parameters of the right ventricle were examined using echocardiography, and collagen in right ventricular tissue was evaluated using the red picrosirius method 24 and 48 hours after the last training session, respectively.

At the end of the 16-week study period, histological investigation revealed widespread interstitial collagen deposition and disruption of myocyte architecture in the exercise group's right ventricular tissue. The exercise group exhibited significantly lower ejection fraction (EF), shortening fraction (FS), systolic (TAPSE), and diastolic (E' wave) function of the right ventricle than the control group, according to echocardiographic findings.

The present study showed that intense and prolonged endurance exercise may cause pathological changes, including fibro-fatty replacement of cardiomyocytes and dysfunction in the right ventricle, and may lead to fatal ventricular arrhythmias.