Athletes' Heart A Benign Syndrome

 

The heart is comprised of cardiac muscle fibers, which differ from the skeletal muscle fibers of the limbs or the smooth muscle fibers of the internal organs. The specialized muscles fibers allow the heart to function as a reliable pacemaker that proves remarkably accurate and strong.
Heart muscle develops as an athlete trains. The changes in cardiac muscle fibers, and heart function as a result of training do not parallel those changes seen in the skeletal system exactly. There are a collection of fairly typical changes that occur that have been named as a clinical syndrome called Athlete’s Heart. Athlete’s Heart is an asymptomatic condition associated with common clinical signs including bradycardia (slow heart rate), a systolic murmur and extra heart sounds that, in an athlete, are usually considered acceptably normal. The vigorous, repetitive training regimens that athletes routinely endure lead to characteristic physiologic and anatomic changes, including enhanced diastolic function, larger left ventricular dimensions and mass, and right ventricular dilatation and systolic dysfunction. These are all basically enlargements of the heart chambers or thickenings of the muscular chamber walls.

Normal Heart

Athlete's Heart

 These changes allow the heart to beat less to pump out the same or greater amounts of blood to surrounding tissues used in exercise. In the first six to 12 weeks of training, the resting heart rate decreases by five to 10 percent. The resting heart rate slows, a sign that the heart is pumping blood with greater efficiency. The large volume of blood flowing through the heart results in a slower, stronger pulse (which can be felt at the wrist and elsewhere on the body) and sometimes heard as a heart murmur. These murmurs, which are specific sounds created as blood flows through the valves of the heart, are no dangerous. The heartbeat of a person with athletic heart syndrome may be irregular at rest but becomes regular when exercise begins. Premature heartbeats may occur occasionally at rest. Blood pressure is virtually the same as in any other healthy person. The myocardial changes that characterize an athlete’s heart are influenced by the type of sport practiced. The physiologic responses to static and dynamic training lead to different adaptations to sustain the specific compulsory demand During aerobic exercise, the consistent exposure of the left ventricle of the heart to increased volume during episodes of sustained elevation in cardiac output causes the ventricular enlargement. Increased afterload during strength and weight training has a propensity to initiate ventricular wall thickening.