Screenings for those with a family member with HCM
The following information is based on available medical research, publications, consensus documents and the entire body of scientific literature on screenings for HCM and basic management of the condition.
In the event of the diagnosis of HCM in a family or an HCM-related death of a family member, it is recommended that all blood relatives be screened. This screening MUST include an EKG/ECG, Echocardiogram, and a cardiac check-up by a cardiologist. Ideally, the cardiologist should have specialized knowledge of Hypertrophic Cardiomyopathy. Due to the fact, HCM is a condition that affects over 1 in 500 people, possibly as many as 1 in 250, it may require the patient to seek out a specialist in the field of HCM to ensure they are being evaluated by a fully knowledgeable medical provider. In many cases, this will require travel out of state and in some cases out of the country. Local cardiologists in most areas will only see a handful of HCM patients at best in their entire practice, thus the patient's needs are better served by a physician who sees the condition, in all its forms, on a regular basis.
Hypertrophic Cardiomyopathy may be suspected because of family history, symptoms, a murmur, or an abnormal EKG/ECG. Many symptoms or signs of Hypertrophic Cardiomyopathy are similar to various other conditions; therefore, it is important to follow the doctor's instructions on complete testing to ensure accurate results. An EKG/ECG records the electrical signals of the heart. In Hypertrophic Cardiomyopathy the EKG/ECG usually shows an abnormal electrical signal due to muscle thickening and disorganization of the muscle structure. In a minority of patients (approximately 10%) the ECG/ECG may be normal or show only minor abnormalities. EKG/ECG abnormalities are not specific to Hypertrophic Cardiomyopathy and will be found in many other conditions.
Presently, the diagnosis of Hypertrophic Cardiomyopathy is made by an ultrasound scan of the heart called "echocardiogram" or "echo" for short. Like the EKG/ECG, this is an entirely safe test. The excessive thickness of the muscle can be easily measured. Additional equipment called "Doppler" ultrasound can produce a color image of the blood flow within the heart and measure the contractions and filling of the heart. Turbulent flow can be detected using the doppler. Therefore, Echo/Doppler provides a very thorough assessment of Hypertrophic Cardiomyopathy.
MRI has been used in more frequent years to gain a more detailed image of the heart. MRI is a newer technology and can produce clearer pictures of the heart and also show the structure of the walls of the heart in such a way that scaring and fibrosis can be viewed.
After a diagnosis is made several other tests may be required. Holtor monitoring is a continuous recording of the heartbeat over a period of 24 to 48 hours. A holtor monitor is a simple and safe test that will detect irregularities of the heartbeat (otherwise known as arrhythmia). Stress tests and Stress Echo's may be used to monitor the heartbeat during exercise as well as blood pressure response and then the echo is used to see if there have been any structural changes due to the exercise. Cardiac catheterization may follow but it is not used on all patients with HCM.
What To Tell Your Family Members About Screenings For HCM
This can often be a difficult and stressful topic for discussion.
A great first step is to customize this letter (click for sample) and give it to family members.
- All first-degree relatives of the affected person should get screened as soon as possible.
Example: if your husband is diagnosed with HCM his parents, siblings and children should all be screened. Think of your family tree and you will want to ensure that those UP (parents), OVER (siblings) and DOWN (children) are all encouraged to be screened. Once a path within the family tree has been found to carry HCM - again that person should go, UP, OVER and DOWN the tree to ensure all parties at risk are screened. Data is limited on the best practices for second degree relatives - so out of caution it is wise to inform them as well and have screening completed.
- Screenings must be done annually from onset of puberty, approximately age 12, to full growth, approximately age 20-25, and every 3-5 years age 25 and over. For those who know genetic status, adults may want to be evaluated every 3 years or more frequently, this is still an area of debate amoung specialists.
- Screenings must include an ECG/EKG, echocardiogram and a visit to a cardiologist - preferably one who understands HCM well and has high quality imaging services (not common in community based cardiology practices).
The general public should be aware that HCM, and for that matter other genetic conditions, is far more common then they may think. It is important for all people to know their family health history and communiciate that with their healthcare providers. Knowing the symptoms of cardiac disorders and reporting them to health care providers is helpful and may lead to additional testing in those with symptoms and family histories of heart disease.
Both the American Heart Association and American College of Cardiology offer guidance for the general public in terms of the role of ECG's in the young otherwise healthy population; at this time it is not felt that this test should be used in the general population as a "screening tool". However, if there is a family history or symptoms a referral to a cardiologist for additional testing including ECG, echocardiogram and other tests may be advised.
Maron, B.J. and Salberg, L. Hypertrophic Cardiomyopathy: For patients, their families and interested physicians. Blackwell Futura: 1st edition 2001,81 pages; 2nd edition 2006, 113 pages; 3rd edition pending publication 2014.
Gersh, B.J., Maron, B.J., Bonow, R.O., Dearani, J.A., Fifer, M.A., Link, M.S., et al. (2011). 2011 ACCF/AHA guidelines for the diagnosis and treatment of hypertrophic cardiomyopathy. A report of the American College of Cardiology Foundation/American Heart Asociation Task Force on practice guidelines. Journal of the American College of Cardiology and Circulation, 58, e212-260.
Maron, B. J., R. A. Friedman, P. Kligfield, B. D. Levine, S. Viskin, B. R. Chaitman, P. M. Okin, J. P. Saul, L. Salberg, G. F. Van Hare, E. Z. Soliman, J. Chen, G. P. Matherne, S. F. Bolling, M. J. Mitten, A. Caplan, G. J. Balady, and P. D. Thompson. CirculationAssessment of the 12-Lead ECG as a Screening Test for Detection of Cardiovascular Disease in Healthy General Populations of Young People (12-25 Years of Age): A Scientific Statement From the American Heart Association and the American College of Cardiology 2014-09-15.