The first step to diagnosing hypertrophic cardiomyopathy is usually obtaining the patient’s family history. Studies have shown that first-degree family members of someone with hypertrophic cardiomyopathy are at greater risk of developing the condition. For this reason, family screening is usually recommended among families with hypertrophic cardiomyopathy.

To diagnose cardiomyopathy, physicians will conduct on a complete physical examination with specific focus on the heart and lungs. Physicians may detect abnormal heart sounds or a murmur through a stethoscope. In most cases, there will be no definitive indication of the condition through a physical exam.

If cardiomyopathy is suspected, the physician can order any number of tests to help with the diagnosis, including:

• Echocardiogram with Doppler ultrasound. This is a non-invasive test that utilizes sound waves to measure the structure and function of the heart. It is the most common test used to diagnose hypertrophic cardiomyopathy. The test produces images that allow a physician to measure the muscle thickness, velocity and blood flow in the heart. It can also determine the ejection fraction, which tends to be abnormal with cardiomyopathies.
  
  During diagnosis, the physician will attempt to measure the degree of outflow obstruction, or the degree to which blood is prevented from flowing normally out of the left ventricle. Patients with greater outflow obstruction are more likely to suffer long-term complications from their condition, although there is not a strong connection between outflow obstruction and the severity of symptoms.
  
  
  

  

• Stress testing. This test is valuable to measure the patient's tolerance for physical activity, as well as detecting any possible arrhythmias. During this test, the patient is asked to exercise while their heart's electrical activity is carefully monitored with an electrocardiogram machine. If a patient cannot exercise, drugs will be administered to mimic exercise. Patients may also be asked to wear a Holter monitor, which records the heart's activity over a period of time - usually 24 to 72 hours.
  
  
• Studies have found that the combination of reduced velocity during diastole (the heart's relaxation phase) and high ejection fraction occur in hypertrophic cardiomyopathy.
  
  
• Chest x-ray. This radiation imaging test allows physicians to view the size and position of the heart.
  
  
• Cardiac catheterization. In this procedure, a thin catheter is placed into an artery, usually in the groin area, which is fed up into the chambers of the heart. The catheter can be used to take pressure measurements in the heart or to deliver contrast medium (dye). The dye can outline the heart and vessels and can detect blockages in the arteries.

Diagnosing the condition in physically active individuals – especially trained athletes – can be challenging. Heart enlargement can be pathological (related to significant heart disease) or physiological (related to exercise or other physical activity). Sometimes referred to as “athlete's heart,” physiological heart enlargement can occur in high-level athletes who engage in regular, sustained and often intense exercise. In most cases, this is not a medically significant or dangerous condition. Studies are exploring ways to better distinguish an enlarge heart from hypertrophic cardiomyopathy. Some researchers feel that a thickness of the left ventricular wall greater than 12 millimeters for male teenage athletes (11 millimeters for female teenage athletes) may be an indication of the disease.

At this point, clinical diagnosis continues to be made on the basis of degrees of hypertrophy. The main obstacle is that individuals with hypertrophic cardiomyopathy can have varying degrees of hypertrophy and symptoms.  In addition, the condition can  develop at different ages, even among members of the same family. With the ongoing progress in identifying the genes and mutations associated with hypertrophic cardiomyopathy, it is hoped that genetic testing will eventually offer an accurate, early way of screening and diagnosing the condition.