Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle (myocardium) becomes abnormally thick — or hypertrophied. This thickened heart muscle can make it harder for the heart to pump blood. Hypertrophic cardiomyopathy may also affect the heart's electrical system.
In a small number of people with hypertrophic cardiomyopathy, the thickened heart muscle can cause symptoms such as shortness of breath, problems in the heart's electrical system resulting in life-threatening arrhythmias and sudden cardiac death. Hypertrophic cardiomyopathy is the most common cause of heart-related sudden death in people under 30.
Possible signs and symptoms include:
- Shortness of breathe, especially during exercise or exertion
- Chest pain, especially during exercise or exertion
- Fainting, especially during exercise or exertion
- Heart palpitations — the sensation of rapid, fluttering or pounding heartbeats
Hypertrophic cardiomyopathy is usually caused by gene mutations. It's thought these mutations cause the heart muscle to grow abnormally thick. People with hypertrophic cardiomyopathy also have an abnormal arrangement of heart muscle fibers. The heart muscle cells become jumbled, known as myofiber disarray. This disarray can contribute to an irregular heartbeat (arrhythmia) in some people.
The severity of hypertrophic cardiomyopathy varies widely. Most people with hypertrophic cardiomyopathy have a form of the disease in which the wall (septum) between the two bottom chambers of the heart (the ventricles) becomes enlarged and obstructs blood flow. This is sometimes referred to as hypertrophic cardiomyopathy with obstruction or hypertrophic obstructive cardiomyopathy. About 70 percent of those with hypertrophic cardiomyopathy have some form of obstruction.
Sometimes hypertrophic cardiomyopathy occurs without significant obstruction of blood flow. However, the heart's main pumping chamber (the left ventricle) may become stiff, which reduces how much blood the ventricle can hold and how much blood gets pumped out to the body with each contraction. Doctors sometimes refer to this as hypertrophic cardiomyopathy without obstruction, or nonobstructive hypertrophic cardiomyopathy.
Hypertrophic cardiomyopathy can be inherited. As a result, close relatives of someone with hypertrophic cardiomyopathy are urged to talk to their doctors about getting screened for the disease.
How it is Diagnosed:
Echocardiogram is the most common test to diagnose hypertrophic cardiomyopathy. Using echocardiogram images, your doctor can see the thickness of your heart muscle, whether blood flow is obstructed and if your heart valves are moving normally.
Electrocardiogram (ECG). This test records the electrical activity of your heart. It's done to detect abnormal electrical signals that may result from the thickened heart muscle
The goals of treatment for hypertrophic cardiomyopathy are to relieve symptoms and prevent sudden cardiac death in those at high risk.
Drug treatment is the best option for most people. Various medications can help relax the muscle and slow the rate so that the heart can pump more efficiently. Some of the drugs your doctor may suggest include beta-blockers, calcium channel blockers or the anti-arrhythmic medications disopyramide or amiodarone.
Some people need surgical intervention and possible pacemakers or implantable defibrillators for treatment of arrhythmias and prevention of sudden cardiac death.
How is this going to affect my lifestyle?
In most people, hypertrophic cardiomyopathy doesn't cause severe problems and they're able to live a normal life. You might be advised not to participate in continuous strenuous activities e.g. competitive sports.