HCM (Hypertrophic Cardiomyopathy)

Hypertrophic cardiomyopathy (HCM), also known as idiopathic hypertrophic subaortic stenosis (IHSS) or asymmetric septal hypertrophy, is a disorder in which the wall separating the left and right ventricles has gotten excessively thick, causing a decreased size in the ventricles.

This makes it harder for the heart to pump blood from these chambers.

HCM is usually asymmetrical, meaning one side of the heart is thicker than the other. This condition is usually inherited, but there have been cases where it has occurred sporadically.

HCM Symptoms

Symptoms of HCM include:

  • Abnormal heart rhythms
  • Angina (chest pain) that occurs at rest
  • Fainting spells after exercises
  • Shortness of breath on exertion or while lying flat
  • Waking up at night because of shortness of breath

HCM Diagnosis

Your UT Southwestern Medical Center doctor may perform several tests to diagnose the problem. Common diagnostic tests include:

Cardiac catheterization
To assess coronary anatomy and degree of obstruction
To reveal increased septal thickness and aortic valve fluttering
To show left ventricle hypertrophy, left atrial enlargement, and changes in the amount of time of contraction of the ventricles to the recovery period of the ventricles
Physical exam
To detect heart murmur, a systolic ejection murmur along the left sternum heard with a stethoscope, which increases in intensity with forced exhalation (valsalva) and diminishes with squatting; to detect carotid upstroke

HCM Treatment

  • Medications, including beta-blockers and calcium channel blockers, are prescribed to reduce chest pain and other symptoms, especially during exercise
  • Antiarrhythmic therapy is used to regulate heart rhythm using an implantable defibrillator
  • Procedures:
    • Alcohol septal ablation
    • Myectomy reduces left ventricle septum thickness
    • Implantable defibrillators may be necessary to regenerate heart rhythms

Request an Appointment

To schedule an appointment with an HCM expert at UT Southwestern's facilities in Dallas or for more information about our services, request an appointment or call 214-645-8300.