athlete's heart

Athletes often have an enlarged heart. When this is a natural, physiological adaptation to regular, endurance exercises, the condition is called athlete's heart. Those with athlete's heart often have a slow heart rate (considerably less than 60 beats per minute). There is no evidence that the condition is detrimental to health. However, when a person's exercise history is not known, athlete's heart is sometimes confused with abnormal, pathological changes associated with some heart diseases. In abnormal enlargements, the changes are not reversible and are accompanied by development of scarlike fibrous tissue (fibrosis) in the heart; athlete's heart is reversible and is not accompanied by fibrosis.

A non-pathological enlargement of the heart resulting from physiological adaptation to training, especially endurance training. The heart enlarges as a result of an increase in the volume of the chamber of the left ventricle and, as revealed by magnetic resonance imaging, of the left ventricle. Athlete's heart is usually associated with bradycardia, but there is no evidence that the condition is detrimental to health. The changes associated with athlete's heart are a normal physiological adaptation to the stresses of training. However, occasionally these changes are confused with those associated with hypertrophic cardiomyopathy and differentiation between the two conditions may require careful clinical examination.

The noun has one meaning:

Meaning #1: enlarged heart commonly found among athletes trained for endurance