Athlete's Heart

Athlete's Heart

Athlete's heart is not a medical condition. It describes the normal changes that occur in the hearts of individuals who participate in intense athletic training. Such changes are subtle. They include small increases in size both of the pumping chamber (ventricle) and filling chamber (atrium), as well as proportionate small increases in the thickness of the heart muscle. Newer studies also point to small increases in the width of the main blood vessel from the heart. These changes are felt to be 'adaptive' – that is, they reflect positive changes that allow the heart an increased ability to supply blood and oxygen to exercising tissues. Since the maximum heart rate tends to vary by individual and by age, the principle mechanism for the heart to increase its output is to increase the amount ejected per beat (also known as the stroke volume). This is achieved by increasing chamber size and compliance.

Because more significant changes in chamber size or wall thickness can be associated with heart muscle disease, we see a lot of athletes in our clinic who have symptoms that might relate to the heart (such as chest pain) or whose hearts have measurements in the gray zone between normal and abnormal. We try to help determine whose heart is normal and whose is not. We carry out maximal exercise tests with expired gas analysis and echocardiography (ultrasound) of the heart. Magnetic resonance imaging is valuable and provides higher resolution images that include the origins of the blood vessels of the heart. We sometimes make use of 24 hour blood pressure monitors to rule out occult high blood pressure. In rare cases, genetic testing can help.

We have a significant interest in Sports Cardiology at Stanford. In addition to seeing athletes in clinic, we are cardiologists to the Stanford athletic teams and the San Francisco 49ers. Fortunately, heart disease is very rare in athletes but there is interest and debate surrounding the best method of screening athletes for heart issues.