Arrhythmias and physical activity

Problem

Our increasingly sedentary lifestyles and lack of physical activity constitute one of the major problems for Western societies. While moderate physical activity is essential for maintaining optimal cardiovascular health, increasing numbers of people are taking part in very high-intensity activities, such as marathons and triathlons. Recent studies carried out at Hospital Clínic-IDIBAPS have shown that this type of exercise may increase the risk of certain cardiac diseases, especially atrial fibrillation and right ventricular arrhythmia.

Approach

The group uses a multidisciplinary approach in order to identify and understand the causes of exercise-induced disorders. It uses animal models, in which it attempts to reproduce the effects of very-high intensity physical exercise and of arrhythmias, and it also conducts studies in patients and healthy volunteers. In order to analyse these, it uses in vitro techniques (such as tissue staining and the study of RNA and protein expression), ex vivo studies (study of the function of isolated cells or organs) and in vivo studies (studies in live animals).

Impact

The results obtained to date have made it possible to confirm that exercise increases the risk of arrhythmias in the atria and ventricles, possibly due to the appearance of scar tissue (fibrosis) in the heart and changes in the autonomic nervous system. Cardiac scar tissue and other disorders of heart structure and function only appear when the exercise is of very high intensity and prolonged over time, whereas moderate exercise appears to be safe and even beneficial.

The group’s research is currently aimed at identifying these consequences of very high-intensity physical exercise and, particularly, at understanding why they occur and how they can be prevented. This information should make it possible to design more efficient diagnostic and therapeutic strategies targeting the initial causes.