How is Hypertrophic Cardiomyopathy Diagnosed?

A variety of tests are used diagnose hypertrophic cardiomyopathy. For detailed procedural information, choose a test or procedure below.

Echocardiogram

The primary test for the clinical diagnosis of HCM is an ultrasound scan of the heart called an echocardiogram. Turbulent flow and the degree of obstruction (if present), as well as valve leakage (mitral regurgitation), can be detected and measured with precision. Therefore, the echocardiogram can provide a thorough structural and functional assessment of HCM, largely avoiding invasive procedures such as cardiac catheterization.

Electrocardiogram (ECG/EKG)

In HCM, the ECG usually shows a variety of abnormal electrical signals due to the muscle thickening. In a minority of HCM patients the ECG may be normal or show particularly minor alterations. ECG abnormalities are also not specific to HCM and may be found in many other heart conditions. In fact, the abnormal ECG in HCM can mimic that of a previous (healed) myocardial infarction; some HCM patients have been advised erroneously that they have previously experienced a "heart attack" (which is a term that literally refers only to the consequence of coronary artery disease).

Cardiac MRI (Magnetic Resonance Imaging)

While two-dimensional echocardiography is the principal clinical test for the diagnosis of HCM, other tests have been used selectively for this purpose. For example, magnetic resonance imaging (MRI), may provide extremely high quality images of the heart, which are often superior to echocardiography. However, MRI scanners (adjusted to use for the heart) are uncommon and generally confined to research centers, and they are extremely expensive rendering the tests quite costly to patients. Also, obese patients and those with implanted devices or claustrophobia may not be suitable candidates for MRI. However, a MRI test could be a useful diagnostic aid in selected patients, including those with unsatisfactory or ambiguous echocardiographic studies.

Laboratory DNA analysis of blood or other tissue is the most definitive method for making the diagnosis of HCM. A commercial genetic test is now available through the Laboratory of Molecular Medicine.

Additional studies may be required in selected patients to assess HCM. (For detailed procedural information, choose a study below.)

Cardiac catheterization

Electrophysiological studies

Exercise testing

Ambulatory Holter monitoring

Radionuclide studies

Adapted from Hypertrophic Cardiomyopathy: For Patients, Their Families, and Interested Physicians, by Barry J. Maron, MD, et al., Copyright 2001, with permission from Futura Media Services, Inc., Armonk, New York