Screening related conditions
Because several well-known and high-profile cases of athletes experiencing sudden unexpected death due to cardiac arrest, such as Reggie White and Marc-Vivien Foé, a growing movement is making an effort to have both professional and school-based athletes screened for cardiac and other related conditions, usually through a careful medical and health history, a good family history, a comprehensive physical examination including auscultation of heart and lung sounds and recording of vital signs such as heart rate and blood pressure, and increasingly, for better efforts at detection, such as an electrocardiogram.An electrocardiogram (ECG) is a relatively straightforward procedure to administer and interpret, compared to more invasive or sophisticated tests; it can reveal or hint at many circulatory disorders and arrhythmias. Part of the cost of an ECG may be covered by some insurance companies, though routine use of ECGs or other similar procedures such as echocardiography (ECHO) are still not considered routine in these contexts. Widespread routine ECGs for all potential athletes during initial screening and then during the yearly physical assessment could well be too expensive to implement on a wide scale, especially in the face of the potentially very large demand.
With a larger left ventricle, the heart rate can decrease and still maintain a level of cardiac output necessary for the body. Therefore, athletes with AHS commonly have lower resting heart rates than nonathletes.The heart becomes enlarged, or hypertrophic, due to intense cardiovascular workouts, creating an increase in stroke volume, an enlarged left ventricle (and right ventricle), and a decrease in resting heart rate along with irregular rhythms. The wall of the left ventricle increases in size by about 15–20% of its normal capacity. No decrease of the diastolic function of the left ventricle occurs. The athlete may also experience an irregular heartbeat and a resting pulse rate between 40 and 60 beats per minute (bradycardia).The level of physical activity in a person determines what physiological changes the heart makes. The two types of exercise are static (strength-training) and dynamic (endurance-training). Static exercise consists of weight lifting and is mostly anaerobic, meaning the body does not rely on oxygen for performance. It also moderately increases heart rate and stroke volume (oxygen debt). Dynamic exercises include running, swimming, skiing, rowing, and cycling, which rely on oxygen from the body. This type of exercise also increases both heart rate and stroke volume of the heart. Both static and dynamic exercises involve the thickening of the left ventricular wall due to increased cardiac output, which leads to physiologic hypertrophy of the heart. Once athletes stop training, the heart returns to its normal size.