In this condition, the heart muscle thickens, which makes it harder for the heart to pump blood. Learn about the causes and treatment.
Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle becomes thickened (hypertrophied). The thickened heart muscle can make it harder for the heart to pump blood.
Hypertrophic cardiomyopathy often goes undiagnosed because many people with the disease have few, if any, symptoms. However, in a small number of people with HCM, the thickened heart muscle can cause shortness of breath, chest pain or changes in the heart's electrical system, resulting in life-threatening irregular heart rhythms (arrhythmias) or sudden death.
In hypertrophic cardiomyopathy (HCM), the muscular heart walls (septum) are much thicker (hypertrophied) than those in a typical heart. The thickening can occur anywhere in the left lower heart chamber (left ventricle).
Signs and symptoms of hypertrophic cardiomyopathy might include one or more of the following:
A number of conditions can cause shortness of breath and fast, pounding heartbeats. It's important to get a prompt, accurate diagnosis and appropriate care. See your health care provider if you have a family history of HCM or any symptoms associated with hypertrophic cardiomyopathy.
Call 911 or your local emergency number if you have any of the following symptoms for more than a few minutes:
Hypertrophic cardiomyopathy is usually caused by changes in genes (gene mutations) that cause the heart muscle to thicken.
Hypertrophic cardiomyopathy typically affects the muscular wall (septum) between the two bottom chambers of the heart (ventricles). The thickened wall might block blood flow out of the heart. This is called obstructive hypertrophic cardiomyopathy.
If there's no significant blocking of blood flow, the condition is called nonobstructive hypertrophic cardiomyopathy. However, the heart's main pumping chamber (left ventricle) might stiffen. This makes it hard for the heart to relax and reduces the amount of blood the ventricle can hold and send to the body with each heartbeat.
People with hypertrophic cardiomyopathy also have a rearrangement of heart muscle cells (myofiber disarray). This can trigger arrhythmias in some people.
Hypertrophic cardiomyopathy is usually passed down through families (inherited). People with one parent with hypertrophic cardiomyopathy have a 50% chance of having the genetic mutation for the disease.
Parents, children or siblings of a person with hypertrophic cardiomyopathy should ask their health care providers about screening for the disease.
Complications of hypertrophic cardiomyopathy can include:
There is no known prevention for hypertrophic cardiomyopathy. It's important to identify the condition as early as possible to guide treatment and prevent complications.
If you have a first-degree relative — a parent, sibling or child — with hypertrophic cardiomyopathy, you might be referred for genetic testing to screen for the condition. However, not everyone with HCM has a currently detectable mutation. Also, some insurance companies don't cover genetic testing.
If genetic testing isn't done, or if the results aren't helpful, then a health care provider might recommend repeated echocardiograms if you have a family member with hypertrophic cardiomyopathy. Adolescents and competitive athletes should be screened once a year. Adults who don't compete in athletics should be screened every five years.
Your health care provider will examine you and ask questions about your signs, symptoms, and medical and family history.
Your provider will likely order tests to diagnose hypertrophic cardiomyopathy (HCM) or rule out other conditions that can cause similar symptoms.
Electrocardiogram (ECG or EKG). Sensors (electrodes) attached to adhesive pads are placed on the chest and sometimes the legs to measure electrical signals from the heart. An ECG can show irregular heart rhythms and signs of heart thickening.
Your health care provider may recommend monitoring your heartbeat at home. A portable ECG device (Holter monitor) can be worn for a day or more to record the heart's activity during daily activities.
The goals of hypertrophic cardiomyopathy treatment are to relieve symptoms and prevent sudden cardiac death in people at high risk. Treatment depends on the severity of symptoms. You and your health care provider will discuss the most appropriate treatment for your condition.
If you have cardiomyopathy and are pregnant or thinking about pregnancy, your health care provider might recommend that you see a doctor experienced in caring for women with high-risk pregnancies (perinatologist or maternal-fetal medicine specialist).
Medications can help reduce how strongly the heart muscle squeezes and slow the heart rate so that the heart can pump blood better. Medications to treat hypertrophic cardiomyopathy and its symptoms might include:
Several surgeries or procedures are available to treat cardiomyopathy or its symptoms. They include:
Septal myectomy. This open-heart surgery might be recommended if medications don't improve symptoms. It involves removing part of the thickened, overgrown wall (septum) between the heart chambers. Septal myectomy helps improve blood flow out of the heart and reduces backward flow of blood through the mitral valve (mitral regurgitation).
The surgery can be done using different approaches, depending on the location of the thickened heart muscle. In one type, called apical myectomy, surgeons remove thickened heart muscle from near the tip of the heart. Sometimes the mitral valve is repaired at the same time.
A septal myectomy is an open-heart procedure in which the surgeon removes part of the thickened, overgrown septum between the ventricles, as shown in the heart on the right.
Lifestyle changes, such as the following, can reduce the risk of complications related to hypertrophic cardiomyopathy.
Being diagnosed with hypertrophic cardiomyopathy can cause a range of difficult emotions. Feelings of grief, fear and anger aren't uncommon.
To better manage your condition:
You may be referred to a doctor trained in diagnosing and treating heart conditions (cardiologist). Here's some information to help you prepare for your appointment.
When you make the appointment, ask about pre-appointment restrictions, such as changing your activity level or your diet. Make a list of:
Questions to ask your health care provider might include:
Don't hesitate to ask other questions you have.
Your health care provider is likely to ask you a number of questions, such as:
Before your appointment, ask your family members if any relatives have been diagnosed with hypertrophic cardiomyopathy or have had unexplained, sudden death.
If exercise makes your symptoms worse, avoid strenuous exercise until you have seen your health care provider and received specific exercise recommendations.