Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy (HCM)

What is it?

Hypertrophic cardiomyopathy consists of several conditions in which the walls of the lower chambers of the heart (the ventricles) thicken (hypertrophy) and become stiff. In time, the thickening of the heart muscle can cause the heart to enlarge. This is called cardiomegaly. Doctors can usually tell if cardiomegaly is present by measuring the size of the heart.

In most patients the septum, which separates the left and right sides of the heart, bulges into the lower left chamber of the heart (the left ventricle). In this form of hypertrophic cardiomyopathy, the muscles in both of the lower chambers often become larger. These thickened muscle walls may partly block the flow of blood through the aortic valve or prevent the heart from relaxing between beats and filling with blood.

Causes, Symptoms and Risk Factors

Symptoms of hypertrophic cardiomyopathy include:

  • Fainting during strenuous exercise
  • Chest pain usually occurring with activity
  • Arrhythmia or heart palpitations
  • Shortness of breath and tired

Persons with hypertrophic cardiomyopathy are at greater risk of developing infective endocarditis because the heart valve which allows blood to flow from the left upper chamber (atrium) to the left lower chamber (ventricle) doesn't close normally. This allows blood to leak back into the atrium.

Sometimes the thickened muscle blocks the flow of blood out of the heart below the aortic valve. This is called hypertrophic obstructive cardiomyopathy.

Causes and Risk Factors

Hypertrophic cardiomyopathy can be present at birth or may be hereditary. Other types develop later because of diseases such as:

  • Acromegaly (an overproduction of growth hormone)
  • Neurofibromatosis (genetic disorder of the nervous system)
  • Tumor of the adrenal glands

Our Services (Tests, Procedures and Treatments)

Diagnostic testing and procedures are the first step in establishing a treatment strategy. A doctor may try to rule out the possibility that symptoms are due to aortic stenosis or coronary artery disease. A doctor may order tests or perform the following procedures:


Treatment usually focuses on eliminating the underlying cause and may include life-style changes, medicines and surgery. Physical exercise or participation in competitive sports may be reduced. Medicines are often the treatment used as it increases the heart's ability to fill with blood between heart beats by slowing down the heart rate and causing the heart muscle to contract less forcefully. This allows the blood to fill the heart more easily.

If drug therapy is not effective, surgery can be done to remove some of the thickened heart muscle that is blocking the blood flow or to replace a damaged valve. If the condition worsens to the point of heart failure, a heart transplant may be needed.

St. Luke's Heart & Vascular