Hypertrophic Cardiomyopathy (HCM)

Hypertrophic cardiomyopathy, or HCM, is the most common inherited heart condition, affecting 1 out of 500 in the population. In this condition, the heart muscle is abnormally thick and usually occurs within the left ventricle, the main pumping chamber of the heart. This thickening may interfere with normal heart function by:

  • Narrowing the flow of blood from the left ventricle
  • Reducing the heart's ability to relax and fill with blood
  • Reducing the valves' ability to function properly

Symptoms of HCM

Many individuals with HCM have no symptoms, while others may have shortness of breath, chest pain, palpitations, lightheadedness, or fainting episodes. Symptoms sometimes occur because of muscle thickening blocking the blood flow from the heart, and this can be treated with medications or surgery.

Diagnosis and Evaluation of HCM

The diagnosis of hypertrophic cardiomyopathy is made by a combination of ECG, echocardiogram, family history and physical examination by a physician. Many patients have a heart murmur on examination as the first clue to diagnosis. Others have symptoms or a known family history of the disorder. Genetic testing is available for patients that can help provide a definitive diagnosis and is a valuable and efficient means of screening family members.

Evaluating the whole family is important since the condition is often passed on to the next generation of a family but may not cause symptoms initially. Some individuals with HCM have a high risk of developing dangerous abnormal heart rhythms (arrhythmias) and may benefit from implantable defibrillators. Fortunately, with a thorough evaluation and appropriate management, the majority of individuals with HCM live full and productive lives.

Treating Cardiomyopathy Symptoms, Preventing Complications

There is no cure for hypertrophic cardiomyopathy, therefore treatment is aimed at alleviating symptoms and preventing complications. Treatment generally begins with medical management, such as a beta blocker, which slows the heart rate and lowers blood pressure. If medical management does not provide the necessary results, other treatment options are available, including a septal myectomy, which reduces the muscle thickening. While this is open-heart surgery, the benefits are immediate, improving symptoms in 90% of patients. And you can be back to work within 4-6 weeks. For patients with life-threatening heart rhythm abnormalities, a pacemaker or implantable cardioverter-defibrillator may be necessary to re-establish a regular heart rate or rhythm.

Because so much still needs to be learned about hypertrophic cardiomyopathy, and about how best to treat it, our clinic has an active research program. Patients and families can assist in this search for new options by agreeing to participate in clinical trials and to allow their tissues, genetic samples and/or data to be used in research. In fact, through our work with genetic testing for our patients, we’ve expanded our practice beyond hypertrophic cardiomyopathy to include other genetic cardiac disorders, including:

Patient Resources

Hypertrophic Cardiomyopathy Information Guide

Make an Appointment

Our HCM program offers expertise in the clinical evaluation of HCM, knowledgeable use of genetic testing, genetic counseling, evaluation of risk for arrhythmias, exercise counseling, defibrillator implantation when needed​, and  surgical evaluation when needed.​ ​To make an appointment to discuss your need for treatment for HCM or another heart condition, contact us toll-free at 888-287-1082 or email us at CVCCallCtr@med.umich.edu. Visit our Make an Appointment page for more information about what to expect when you call us.