What is hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy is most often caused by abnormal genes in the heart muscle. These genes cause the walls of the heart chamber (left ventricle) to become thicker than normal.
The thickened walls can become stiff, which can reduce the amount of blood absorbed and pumped to the body with each heartbeat.
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Obstructive and non-obstructive HCM
In obstructive HCM, the thickened part of the heart muscle, usually the wall (septum) between the two lower chambers (ventricles), blocks or reduces blood flow from the left ventricle to the aorta. Most people with HCM have this type.
In non-obstructive HCM, the heart muscle is thickened but does not block blood flow out of the heart.
Signs, symptoms and risks
Some people with hypertrophic cardiomyopathy have no symptoms, while others may only experience symptoms during exercise or exertion. Some people may not have any signs or symptoms in the early stages of the disease but may develop them over time.
Knowing the signs and symptoms of HCM is important. This can help get an early diagnosis, when treatment can be most effective.
Signs and symptoms of HCM include:
- Chest pain, especially during physical exertion
- Shortness of breath, especially during physical exertion
- Fatigue
- Arrhythmias (abnormal heart rhythms)
- Dizziness
- Dizziness
- Fainting (syncope)
- Swelling of the ankles, feet, legs and abdomen
HCM is a chronic condition that can get worse over time. This can lead to decreased functioning and quality of life, long-term complications, and greater financial and social burden.
People with HCM may need lifestyle changes, such as limiting activity, to adapt to their illness.
As HCM progresses, it can lead to other health problems. People with HCM are at higher risk of developing atrial fibrillationwhich can lead to blood clots, stroke and other heart-related complications. HCM can also lead to heart failure. This can also lead to Sudden cardiac arrestbut it is rare.
HCM is considered the most common cause of sudden cardiac death in young people and competitive athletes in North America, although it is rare.
Get a diagnosis
Hypertrophic cardiomyopathy is most often hereditary and is the most common form of genetic heart disease. It can occur at any age, but most are diagnosed in middle age.
An estimated 1 in 500 people have HCM, but a significant percentage of patients go undiagnosed. Of those diagnosed, two thirds have obstructive HCM and one third have non-obstructive HCM.
A cardiologist or pediatric cardiologist often diagnoses and treats HCM. You may also be referred to a cardiomyopathy center where the care team has specialized training.
The diagnosis of HCM is based on your medical history, family history, physical examination, and diagnostic test results.
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Medical and family history
Knowing your medical history and any signs and symptoms you may have is an important first step. Since HCM can be passed from parents to children, your doctor will also want to know if anyone in your family has been diagnosed with HCM. heart failure Or cardiac arrest. If a person has been diagnosed with HCM, first-degree relatives, including siblings and parents, should also be checked. Learn more about genetic testing with our information guide (PDF).
Physical examination
Your doctor will listen to your heart and lungs with a stethoscope. If they hear a rustling or whistling sound called a murmur, it could mean there is a problem with blood flow to the heart, which may suggest HCM.
Diagnostic tests
The diagnosis is usually made by echocardiogram. It checks the thickness of the heart muscle and blood flow in the heart. In some cases, another type of echocardiogram, transesophageal echo (or TEE), can be carried out. A TEE is performed using a probe inserted into the throat while the patient is sedated.
Other diagnostic tests may include:
Diagnostic procedures
Confirmation of diagnosis or preparation for surgery may also involve one or more medical procedures during cardiac catheterization.
Treatment and management of HCM
There is currently only one disease-specific drug to treat hypertrophic cardiomyopathy. Mavacamten, a drug approved by the FDA in April 2022, is used to treat the obstructive form of HCM in people with symptoms.
For people with HCM who have no symptoms, a healthy heart way of life It is recommended to stay active, eat a healthy diet, maintain a normal weight, get good quality sleep and not smoke. If you have other health problems such as high blood pressure or diabetes, it is important that these are taken care of to avoid heart complications that can develop if left unchecked.
For those experiencing symptoms, the focus is on managing symptoms with medications and procedures.
Drugs
It is important to take the medications prescribed by your healthcare professional. These medications can help improve symptoms and functioning, but may have side effects. Medications that may be prescribed for HCM include:
May improve symptoms
May improve symptoms and function
Unlike other HCM medications, mavacamten (Camzyos), a cardiac myosin inhibitor, is a new type of medication used to improve the symptoms and function of patients with obstructive-type HCM who have mild symptoms. to moderate with activity. Unlike other medications used to treat HCM, mavacamten targets the underlying cause of obstructive HCM.
*Mavacamten is not included in the current 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy because it was approved by the FDA in 2022.
Procedures
A range of surgical and non-surgical procedures can be used to treat HCM:
- Septal myectomy – Septal myectomy, also called septal reduction therapy, is an open heart surgery. It is considered for people with obstructive HCM who, despite taking medications for HCM, continue to have severe symptoms. A surgeon removes part of the thickened septum that protrudes into the left ventricle. This clears the obstruction and restores blood flow through the heart and out to the body.
- Alcohol septal ablation (non-surgical procedure) – Also called non-surgical septal reduction therapy, alcohol septal ablation is a procedure in which ethanol (a type of alcohol) is injected through a tube into the small artery that supplies blood to the area of the heart muscle thickened by the HCM. Alcohol causes these cells to die. The thickened fabric shrinks to a more normal size. The risks and complications of heart surgery increase with age. For this reason, ablation may be preferred over septal myectomy in elderly patients with other medical problems.
- Cardiac Implantable Electronic Devices (CIEDs) – Several types of devices can be implanted in the body to help the heart work better, including:
- Implantable cardioverter defibrillator (ICD) – An ICD helps maintain a normal heart rhythm by sending an electrical shock to the heart if an irregular heart rhythm is detected. This reduces the risk of sudden cardiac death.
- Pacemaker – This small device uses electrical impulses to encourage the heart to beat at a normal rate. This is used for people with a heart rate that is too slow.
- Cardiac Resynchronization Therapy (CRT) Device – This device coordinates contractions between the left and right ventricles of the heart.
- Heart transplant – In HCM patients with advanced and terminal disease, heart transplantation may be considered. In this procedure, a person’s diseased heart is replaced with a healthy donor heart.
Prognosis
Long-term outcomes for people with HCM are very good, and most patients with HCM have a normal life expectancy without significant limitations or complications.
However, a small number of people with HCM are at risk of complications, including heart failure and sudden death. The risk of heart complications can vary from family to family and among different members of the same family. It is therefore important that your healthcare team identifies those most at risk of developing these complications so that preventative treatment can be provided.
