Hypertrophic cardiomyopathy is characterized by the abnormal growth of muscle fibers on the heart muscle, often causing a thickened septum. The thickening of the muscle can result in a resistance of blood flow both in and out of the heart’s chambers. When this occurs, the heart must work harder to pump blood throughout the body.

Hypertrophic cardiomyopathy is generally considered a genetic disease that affects about one percent of the population, or one in 500 people. Most hypertrophic cardiomyopathy shows no symptoms. However, if symptoms develop, they most often occur during puberty and young adulthood. A possibly related condition, called inappropriate left ventricle hypertrophy, occurs in people over 60.

Among patients who develop symptoms, most are mild to moderate and progress slowly with age. Among a small subset of patients, however, symptoms can be severe and life threatening. These patients are at increased risk for sudden cardiac death, stroke and heart failure. According to the American Heart Association, 36 percent of young athletes who die suddenly have definite or probable hypertrophic cardiomyopathy.

The name hypertrophic cardiomyopathy is derived from the following:

Whether or not patients are experiencing symptoms, it is important to avoid strenuous exercises such as weight lifting. Unless otherwise advised by a physician, controlled aerobic exercises such as walking or even running, can be safe. However, these forms of exercise should never continue to the point of dehydration and/or exhaustion because this could trigger a potentially fatal abnormal heart rhythm (arrhythmia). Other strategies to maintain a normal heart rhythm include taking antiarrhythmic medications and the surgical insertion of a pacemaker or implantable cardioverter defibrillator.

In about 5 percent of patients, surgery to reduce the size of the septum (septal myomectomy) may be necessary. Alternatively, a procedure called septal alcohol ablation may be used. During this catheter-based procedure, a physician injects alcohol into the blood supply to the septal part of the left ventricle heart muscle, causing the outflow track of the left ventricular pumping chamber to allow more blood flow to the body.

While hypertrophic cardiomyopathy is a potentially serious condition, sometimes with an unpredictable onset of symptoms, many patients experience only minor intrusion from the disease, enjoying a normal lifespan without the need for major medical procedures.