Hypertrophic Cardiomyopathy (HCM)

Hypertrophic cardiomyopathy (HCM) is a common genetic condition that affects the heart muscle. HCM thickens the walls of the heart, limiting the amount of blood it’s able to pump throughout the body.

HCM Symptoms and Diagnosis

Many people with HCM don’t experience symptoms which is why it can go undiagnosed for so long. When symptoms do occur, they typically present as:

  • Chest pain
  • Trouble breathing
  • Fatigue
  • Fainting
  • Dizziness
  • Rapid or irregular heartbeat (palpitations)

There are two types of HCM: non-obstructive HCM and obstructive HCM. Both varieties result in thicker heart walls, but obstructive HCM is associated with impacted blood flow.


To be diagnosed with HCM, you’ll be asked about your symptoms and medical history, receive a comprehensive physical exam, and may undergo cardiac testing. The most common imaging test we use to assist with diagnosis is an echocardiogram which measures the heart’s size, thickness, and ability to pump blood. Depending on your situation, we may recommend additional tests.

Because HCM is genetic, it often runs in families. As a result, your children, siblings, and parents may want to undergo cardiac screening to find out if they also have HCM. If genetic testing determines that a mutation is responsible for the HCM diagnosis, your physician will speak to you and your family about preventive measures and treatments that will reduce your risk of developing cardiovascular disease.

At the BIDMC Center for Cardiovascular Genetics, we offer a personalized evaluation and management plan that includes testing, genetic counseling, and treatment options for patients and families with suspected or diagnosed HCM.

Understanding Hypertrophic Cardiomyopathy
In this animation, we explain the symptoms, causes, and treatments for patients with HCM.

HCM Treatment at BIDMC

At the CardioVascular Institute, our multidisciplinary team provides the full range of treatment options to patients with HCM, ranging from medical management to surgery and implantable devices.

Medical Management

Many patients with HCM work to control their symptoms with medication. However, if drug treatments are ineffective, there are other options available.

Implantable Devices

Implantable cardioverter defibrillators (ICDs) keep the heart beating normally in high-risk patients. An ICD is an implant that can sense dangerously irregular heartbeats (arrhythmias) and correct them through slight shocks. Learn more about ICDs and Arrhythmia Services.

Minimally Invasive Treatment

Alcohol septal ablation is a minimally invasive procedure that uses alcohol to shrink the heart muscle, leaving more space for blood to flow normally. Learn more about Interventional Heart Care.

Heart Surgery

A small number of patients benefit from a septal myectomy, a surgical procedure that reduces the thickness of the heart muscle caused by HCM and normalizes blood flow.

Hassan Rastegar, MD, BIDMC HCM Surgical Director, is an internationally known cardiac surgeon. Dr. Rastegar has extensive experience with HCM and has performed over 1,000 successful surgeries (septal myectomies) to treat severe symptoms of HCM. Learn more about our Cardiac Surgery Treatments and Services.

Hypertrophic Cardiomyopathy (HCM) Clinic

The HCM Clinic at the Center for Cardiovascular Genetics brings together experts in cardiology, genetics, imaging, and surgery to provide coordinated care for patients with HCM.

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