Hypertrophic cardiomyopathy (HCM) is an inherited form of heart disease. With HCM, the walls of the heart’s main pumping chamber, the left ventricle, become thick and stiff. Over time, the heart may not be able to pump enough blood to the body.
Many people with HCM are not diagnosed. HCM doesn’t always cause symptoms.
However, a heart murmur is a classic finding in people with symptomatic HCM.
A usual heartbeat has two sounds: lub-dub. These are caused by your heart valves opening and closing as they pump blood through the four chambers of your heart.
A heart murmur is an extra, unusual sound in the heartbeat caused by turbulence in blood flow in the heart. This causes a whooshing or swishing sound when your doctor listens to your heart with a stethoscope.
A heart murmur is different from an arrhythmia, a disruption in the electrical signals that control the heart’s rhythm.
Heart murmur in HCM
With HCM, a heart murmur has a distinct sound. It may also change with position. Your doctor may ask you to squat and stand and listen for changes in the murmur.
Other causes of heart murmur
While a heart murmur may be a sign of HCM, other heart-related issues can also cause murmurs, including:
- heart valve problems
- a hole in the heart
- persistent ductus arteriosus (PDA)
Less serious causes of a heart murmur include:
- thyroid disease
Many people with HCM don’t have symptoms. In these cases, HCM may be diagnosed by chance or when a healthcare professional notices the characteristic murmur during a physical examination.
When HCM symptoms do occur, along with a heart murmur, they can
- chest pain
- shortness of breath
- fast or fluttering heartbeat (palpitations)
- swelling in the feet, ankles, legs, belly
Chest pain, dizziness, and shortness of breath may appear only when you exercise. HCM tends to worsen over time. It may eventually become hard to do daily activities.
If you have a heart murmur or other symptoms, or if there’s a history of HCM in your family, see your primary care doctor or a cardiologist. The doctor will ask about your personal and family health histories, listen to your heart with a stethoscope, and perform further testing.
HCM isn’t curable, but treatments are available. Medication, surgery, and lifestyle changes can help manage symptoms and prevent complications.
Get a diagnosis
The main test for HCM is an echocardiogram. It uses sound waves to produce a live image of your heart on a monitor.
Other tests that may be part of the
- heart MRI
- heart CT scan
- electrocardiogram (EKG)
- exercise stress tests
- heart rhythm monitoring, such as Holter monitor
Ask about genetic testing
Genetic testing is important in diagnosing and treating HCM. If a parent has the condition, you have a
Various gene mutations are linked to HCM. A blood test can identify these genetic changes.
A genetic test can also give your doctor information about your outlook.
If you do have genes linked to HCM, your doctor or a genetic counselor may recommend that your close relatives also get tested.
Follow a heart-healthy lifestyle
If you don’t have symptoms, you may be able to manage HCM with a few lifestyle changes. And if you do have symptoms, your doctor might recommend these practices to
- Stay active. Exercise can help to control your blood pressure and heart rate. Ask your doctor which types of activities are safest for you. If you have any shortness of breath or chest pain during a workout, stop and call your doctor.
- Eat a healthy diet. A heart-healthy diet includes a variety of colorful fruits and vegetables, whole grains, fish, and other lean proteins. Your doctor might recommend cutting back on saturated fats, salt, and sugar to help protect your heart.
- Limit alcohol. Drinking can further reduce the amount of blood your heart can pump.
- Quit smoking if you smoke. The chemicals in cigarette smoke narrow arteries and can worsen HCM symptoms.
- Check your numbers. Try to keep track of your blood pressure and blood sugar levels if you have high blood pressure or diabetes. These conditions can contribute to heart complications.
Take medication if needed
For many people, monitoring HCM is the main treatment approach. For others, treating HCM and its symptoms may be necessary.
Mavacamten (Camzyos) is the only treatment for HCM approved by the Food and Drug Administration. This drug helps improve blood flow and relieve symptoms in people with the obstructive form of the disease, where the enlarged wall of the left ventricular septum is blocking flow from the heart.
A few other medications may help
- calcium channel blockers
- anti-arrhythmia drugs
- blood thinners for those with HCM who develop atrial fibrillation
Work with your doctor to discuss which treatment is best for you.
Have a procedure if needed
If you have severe symptoms or you’re at risk of complications, you may need a procedure to improve blood flow or prevent cardiac arrest. These are some of the
- Implantable cardioverter defibrillator (ICD). This device is placed inside your chest. An ICD monitors your heartbeat and delivers an electric shock to prevent abnormal heart rhythms.
- Septal myectomy. This open-heart surgery removes part of the thickened septum to improve blood flow from the ventricles.
- Alcohol septal ablation. In this nonsurgical procedure, the doctor injects a form of alcohol into the artery that supplies blood to the thickened part of your heart muscle. The alcohol causes scarring, which shrinks the enlarged part of your heart.
A heart murmur can be a sign of HCM, an inherited form of heart disease that can cause abnormal heart rhythms and sometimes lead to complications like cardiac arrest.
Receiving an HCM diagnosis, making heart-healthy lifestyle changes, and finding the right treatment approach may prevent help complications and improve the outlook for people with HCM.