Dr. Alykhan Abdulla, BSC, MD, LMCC, CCFPC, DipSportMed CASEM, FCFCP, CTH (ISTM), CCPE, Masters Cert Phys Leader, ICD.D Assistant Professor University of Ottawa Faculty of Medicine, Academic Clinical Professor University of Ottawa Faculty of Nursing Medical Director The Kingsway Health Centre, The Kingsway Travel Clinic, The Kingsway Cosmetic Clinic, Beechwood Medical Cosmetic Physio Pharmacy, Editor in Chief/Author Journal of Current Clinical Care SPORTS MEDICINE, Vice Chair Section of General and Family Practice Ontario Medical Association, Board Director Eastern Ontario Regional Lab Association, Bruyere Foundation
Abstract
A common term for an enlarged heart that is associated with repeated strenuous exercise is athletic heart syndrome (AHS). This article reviews AHS, other serious conditions that appear similar to AHS, and how to identify a young athlete at risk for sudden cardiac death.
Key Words: athletic heart syndrome, enlarged heart, strenuous exercise, sudden cardiac death.
Athletic heart syndrome (AHS) is a common term for an enlarged heart associated with repeated strenuous exercise. As a result of the increased workload required of the heart, it will increase physiologically by enlarging chambers and muscle mass, or hypertrophy by enlarging the size of the chambers and increasing the volume of blood pumped per stroke. Consequently, the heart has to contract less frequently and, at rest, will beat as few as 45 times per minute as compared with an average number of 75 beats in a normal heart.
The athlete who needs a high capacity for oxygen transport benefits from a larger stroke volume, a low heart rate and a hypertrophied ventricular wall. But while the heart continues to function adequately as a pump by altering its rate and contractility when confronted with sudden demand, chronic demand causes dilation and hypertrophy of the cardiac muscle.
The changes in heart structure and function seen in AHS would suggest illness if seen in non-athletes. In athletes, however, these are normal physiologic adaptations to physically demanding lives. When abnormalities in heart structure or function are detected in an athlete, it is important to ensure the abnormalities are indeed due solely to exercise conditioning, and not to a cardiac disorder.
