When Does Hypertrophic Cardiomyopathy Develop?

Although hypertrophy may be present at birth or in childhood, it is much more common for the heart to appear normal at this time. Occasionally, Hypertrophic Cardiomyopathy is the cause of a stillbirth or develops during infancy, with heart failure, which may be fatal.

However, hypertrophy more commonly develops in association with growth and is usually apparent by the late teens or early twenties. Once hypertrophy appears there is rarely a significant change in muscle thickness in the years of adult life. Patients can be diagnosed at any age, from birth to age 80 and beyond.

Children and adolescents with the condition usually come to attention when a family screening is performed after an adult in the family is found to be affected or at the presence of a heart murmur that is evaluated more closely.

Approximately 50% of adults with the condition present with symptoms, the average age of diagnosis within the HCMA database is 35 years.

In the remainder, the diagnosis is made during family screening or following the detection of a murmur or abnormality on routine electrocardiogram (ECG). A growing number of HCM patients are being identified later in life and are referred to as "adult onset". In the early literature the occurrence of adult onset appeared rare, now we know it to be far more common. Therefore, in recent years, those in the HCM community have encouraged those with a family history of HCM, who have not had genetic testing, continue to be screened every 5 years after the age of 25, or if symptoms occur sooner, for the remainder of life. For screening information see Family Screenings on this web site.

Citations:

• American College of Cardiology/European Society of Cardiology clinical expert consensus document on hypertrophic cardiomyopathy. A report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines.Maron BJ, McKenna WJ, Danielson GK, Kappenberger LJ, Kuhn HJ, Seidman CE, Shah PM, Spencer WH 3rd, Spirito P, Ten Cate FJ, Wigle ED; Task Force on Clinical Expert Consensus Documents. American College of Cardiology; Committee for Practice Guidelines. European Society of Cardiology. J Am Coll Cardiol. 2003 Nov 5;42(9):1687-713
• Hypertrophic Cardiomyopathy for Patients, Their Families and Interested Physicians Second Edition, Maron and Salberg, Wiley publishing 2006