Hypertrophic Cardiomyopathy Diagnosis

As part of an experienced center, your Stanford hypertrophic cardiomyopathy team knows that the heart of each person with HCM is unique in the way it looks, how it functions, and what symptoms it may cause. HCM can be difficult to diagnose, so we make sure to consider other diseases that look like HCM but have different treatments, such as athlete’s heart, cardiac amyloidosis, cardiac sarcoidosis, hypertensive heart disease, Fabry disease, or hemochromatosis.

Our team has the experience and expertise to draw those distinctions. They carefully examine your tests and imaging to look for subtle findings that point toward one diagnosis or another. Our genetic counselors will also work with you to look for clues in your family history. If you have any cardiomyopathy, heart failure, or sudden unexplained death in your family, please be sure to mention it to the team. The genetic counselor will also guide you through the process of considering HCM genetic testing and help you understand what the results mean for you and your family. Learn more about genetic testing, counseling, and evaluation for heart disease.

Diagnosing and treating hypertrophic cardiomyopathy often involves blood tests, imaging, and other tools. Our specialists use the latest technologies, many developed or refined at Stanford, and have the experience to provide expert interpretation:

• Cardiac catheterization: After placing a needle in a wrist or groin artery, we thread narrow tubes called catheters through arteries toward your heart. During cardiac catheterization, we may take X-rays of your heart vessels after injecting contrast dye, a test called an angiogram. During this test, we can also more precisely measure the pressure in different parts of your heart and lungs to develop a more individualized plan. We may also take a small sample of heart muscle, called a biopsy, for more testing.
• Cardiac magnetic resonance imaging (MRI): Magnets, radio waves, and a computer produce high-resolution still and moving images of the heart and its blood vessels. It is mostly used to get more detailed measurement of the heart thickness and to see if there is scaring / fibrosis in the heart. This information can provide additional information about your risk for HCM complications. 
• Echocardiogram (echo): Ultrasound, or sound waves, creates a moving picture of your heart and is the main way we confirm a diagnosis. We use echocardiograms to gauge the size, shape, and function of your heart and its chambers and valves. At times, we may ease an ultrasound probe down the esophagus and closer to the heart in a test called transesophageal echocardiogram (TEE).
• Electrocardiogram (EKG): We use electrocardiograms to record the heart’s electrical impulses, collecting information about the heart’s rhythm and sometimes discerning clues about its structure.
• Holter and event monitors: Wearable devices known as Holter monitors perform electrocardiogram monitoring outside the hospital for a set period, typically 24 to 48 hours. Event monitors are similar but can be worn for longer periods and allow you to trigger additional recording when you experience an unusual sensation.
• Stress electrocardiogram (EKG) test: A traditional stress EKG test checks your electrocardiogram while you exercise on a treadmill or stationary bicycle. It can help identify coronary artery disease or arrhythmias.
• Stress echocardiogram (echo) test: This test is similar to a traditional stress EKG but also uses a heart ultrasound to take images of your heart before and after you exercise on the treadmill or stationary bicycle.
• Cardiopulmonary stress test (CPX): This highly specialized exercise test combines an EKG, echocardiogram, and a breathing mask to best assess your heart’s function and your exercise capacity. This test helps guide your personal medical recommendations, with the data used to tailor a safe exercise program for you. It is available only at certain centers, and our team collaborated in research to prove its effectiveness.
• Genetic testing: A genetic counselor may recommend a blood or saliva test to identify variations in DNA. Genetic testing can help diagnose an inherited heart condition, as well as help guide clinical recommendations for at-risk family members.