Hypertrophic cardiomyopathy (HCM) is an inherited disease of the heart muscle. HCM can cause the wall of the heart muscle to thicken. When the walls get too thick, the heart muscle functions inefficiently, causing some patients to have obstruction to blood flow from the heart.
HCM appears in all racial groups. The incidence of HCM is about 0.2% to 0.5% of the general population. An estimated 30,000 children are affected by cardiomyopathy of all types (dilated, hypertrophic, restricted, etc.). Once HCM has been identified in a family, it is advisable to have all immediate family members tested as soon as possible, as the disease has a genetic link.
People with hypertrophic cardiomyopathy (HCM) can have the following symptoms:
- Shortness of breath
- Chest pain or discomfort
- Palpitations or the sensation of feeling the heart beat
HCM is also associated with abnormal heart rhythms, which can sometimes be life threatening. A minority of people with HCM will suffer from the most serious complications, which include sudden death, heart failure and stroke. It is important to note that HCM has a wide range of severity. Some people may not experience symptoms and may have normal heart evaluations well into adulthood. Others may have serious complications at a young age, including heart failure or sudden cardiac death.
It is difficult to predict whether an individual will have a mild form of HCM or a more severe form. HCM can be a major cause of death in young athletes who appear healthy but die during intense exercise.
All patients with hypertrophic cardiomyopathy are tested to attempt to ascertain which patients are at risk for sudden cardiac death. In those patients deemed to be at high risk, defibrillator therapy is an option (device implant).
For less risky patients, beta-blocker medical therapy can be very successful. Beta blockers are often prescribed as the first medical treatment for HCM in children.
Severe symptoms in non-obstructive HCM may actually be more difficult to treat because there is no obvious target (obstruction) to treat. Medical therapy with verapamil and beta-blockade may improve symptoms. Diuretics should be avoided.
Surgical septal myectomy is an open heart operation done to relieve symptoms in patients who remain severely symptomatic despite medical therapy.