What Is Hypertrophic Cardiomyopathy?
Hypertrophic cardiomyopathy (HCM) is associated with thickening of the heart muscle, most commonly at the septum between the ventricles, below the aortic valve. This may lead to stiffening of the walls of the heart and abnormal aortic and mitral heart valve function, both of which may impede normal blood flow out of the heart.
What Are the Symptoms of Hypertrophic Cardiomyopathy?
Many people with HCM have no symptoms or only minor symptoms, and live a normal life. Other people develop symptoms, which progress and worsen as heart function worsens.
Symptoms of HCM can occur at any age and may include:
- Chest painor pressure (occurs usually with exercise or physical activity, but can also occur with rest or after meals)
- Shortness of breath (dyspnea), especially with exertion
- Fatigue (feeling overly tired)
- Fainting (caused by irregular heart rhythms, abnormal responses of the blood vessels during exercise, or no cause may be found)
- Palpitations (fluttering in the chest) due to abnormal heart rhythms (arrhythmias), such as atrial fibrillation or ventricular tachycardia
- Sudden death (occurs in a small number of patients with HCM)
What Causes Hypertrophic Cardiomyopathy?
HCM can run in families, but the condition may also be acquired as a part of aging or high blood pressure. In other instances, the cause is unknown.
How Is Hypertrophic Cardiomyopathy Diagnosed?
HCM is diagnosed based on medical history (your symptoms and family history), a physical exam, and echocardiogram results. Additional tests may include blood tests, electrocardiogram, chest X-ray, exercise stress test, cardiac catheterization, CT scan, and MRI.
How Is Hypertrophic Cardiomyopathy Treated?
Treatment of HCM depends on whether there is narrowing in the path that blood takes to leave the heart (called the outflow tract); how the heart is functioning; and if arrhythmias are present. Treatment is aimed at preventing symptoms and complications and includes risk identification and regular follow-up, lifestyle changes, medications, and procedures as needed.
What Lifestyle Changes Are Recommended to Treat Hypertrophic Cardiomyopathy?
- Diet. Maintain adequate hydration, unless your doctor is restricting your fluids (fluid and salt restrictions may be necessary for some patients if heart failure symptoms are present). Ask your doctor about specific fluid and dietary guidelines, including information about alcoholic beverages and caffeinated products.
- Exercise. Your doctor will tell you if you may exercise or not. Most people with cardiomyopathy are able to do non-competitive aerobic exercise. However, your doctor may ask you not to exercise, based on your symptoms and the severity of your disease. Heavy weight lifting is not recommended.
- Regular follow-up visits. Patients with HCM should have an annual follow-up visit with their cardiologist to monitor their condition. Follow-up appointments may be more frequent when HCM is first diagnosed.
What Medications Are Used to Treat Hypertrophic Cardiomyopathy?
Drugs are often used to treat symptoms and prevent further complications of HCM. Medications can help relax the heart and reduce the degree of obstruction so the heart can pump more efficiently. Beta-blockers and calcium channel blocker blockers are two classes of medications that may be prescribed. If you have an arrhythmia, your doctor may prescribe medications to control your heart rate or decrease the occurrence of arrhythmias.
You may be told to avoid certain medications, such as nitrates, because they lower blood pressure, or digoxin, because it increases the force of the heart's contraction.
Both obstructive and non-obstructive HCM symptoms may be treated with medications. If heart failure occurs, treatment is aimed at controlling it through heart failure medications and diet changes.
Your doctor will discuss which medications are best for you.
What Procedures Are Used to Treat Hypertrophic Cardiomyopathy?
Procedures used to treat HCM include:
Septal myectomy. During this surgical procedure, the surgeon removes a small amount of the thickened septal wall of the heart to widen the outflow tract (the path the blood takes) from the left ventricle to the aorta.
Ethanol ablation. First, a cardiologist (heart doctor) performs a cardiac catheterization to locate the small coronary artery that supplies blood flow to the septum. A balloon catheter is inserted into the artery and inflated. A contrast agent is injected to locate the swollen septal wall that narrows the passageway from the left ventricle to the aorta. When the abnormal area is located, a tiny amount of pure alcohol is injected through the catheter. The alcohol kills the cells on contact, causing a small "controlled" heart attack. The septum then shrinks back to a more normal size over the following months, widening the passage for blood flow.
Implantable Cardioverter Defibrillators (ICD). ICDs are suggested for people at risk for life-threatening arrhythmias or sudden cardiac death. The ICD constantly monitors the heart rhythm. When it detects a very fast, abnormal heart rhythm, it delivers energy to the heart muscle to cause the heart to beat in a normal rhythm again.
Hypertrophic Cardiomyopathy, Sudden Death, and Endocarditis
A small number of people with HCM have an increased risk of sudden cardiac death. People at risk include:
- Those who have family members who have had sudden cardiac death
- Young people with HCM who have had several episodes of fainting
- Those who have an abnormal blood pressure response with exercise
- Adults who have a history of arrhythmia with a fast heart rate
- Those with severe symptoms and poor heart function
If you have two or more risk factors for sudden cardiac death, your doctor may treat you with medications to prevent arrhythmias or with an ICD. Most people with HCM are at low risk for sudden cardiac death. Talk to your doctor about any concerns you may have.
How Can I Prevent Endocarditis?
People with obstructive HCM may be at increased risk for infective endocarditis, a potentially life-threatening condition. Ask your doctor if you need to take endocarditis precautions, which include:
- Telling all your doctors and dentist you have HCM. They might prescribe antibiotics to prevent an infection before performing any procedures on you that may cause bleeding (dental, respiratory, and gastrointestinal procedures).
- Calling your doctor if you have symptoms of an infection.
- Taking good care of your teeth and gums.