Copyright 2004 Heart Disease Weekly via &
Heart Disease Weekly

August 29, 2004

The prevalence of hypertrophic cardiomyopathy has been studied in older
Native Americans.

According to published research from the United States, "Recognition of the
frequency with which hypertrophic cardiomyopathy (HCM) occurs in the general
population is critical to understanding its demographics and public health

"However, few data are available for estimating HC prevalence in large
populations of different age strata and ethnic or racial groups. The Strong
Heart Study is a prospective, population-based epidemiologic survey of
cardiovascular disease in residents of 13 geographically diverse American Indian

"The study population was comprised of 3,501 subjects with echocardiograms
performed in 1993 and 1995 to determine the prevalence of HCM in middle-aged and
older adult populations," B.J. Maron and coinvestigators, Minneapolis Heart
Institute Foundation, explained. "Evidence of the HCM phenotype was present in 8
previously undiagnosed patients (0.23%; 2 of 1,000) based on a left ventricular
(LV) wall thickness greater than or equal to15 mm and a nondilated cavity that
was not associated with another cardiac disease and was sufficient to produce
the magnitude of hypertrophy evident.

"Ages were 51 to 77 years (mean 64 ± 9). Four subjects were men and 4 were
women, with prevalences by gender of 0.3% (3 of 1,000) and 0.18% (1.8 of 1,000),
respectively. Maximum LV thicknesses were 19 to 29 mm (mean 21 ± 3)."

The authors continued, "Two subjects had mitral valve systolic anterior
motion, which was sufficient to produce LV outflow obstruction at rest in I
patient. Different electrocardiographic abnormalities were present in five

"In conclusion," Maron and coworkers wrote, "clinically unrecognized HCM was
present in 1:500 of an aging American Indian cohort. This prevalence was similar
to that reported in other general populations comprised of younger subjects of
other races, offering evidence that HC is a relatively common genetic disease
with widespread occurrence within the United States."

Maron and coauthors published their findings in American Journal of
Cardiology (Prevalence of hypertrophic cardiomyopathy in a population-based
sample of American Indians aged 51 to 77 years (The Strong Heart Study). Am J
Cardiol, 2004;93(12):1510-1514).

Additional information can be obtained by contacting B.J. Maron, Minneapolis
Heart Institute Foundation, Hypertroph Cardiomyopathy Center, 920 E 28th St.,
Suite 60, Minneapolis, MN 55407 USA.