Differences in Echocardiographic Findings and Systemic Hemodynamics
among Non-Diabetic American Indians in Different Regions:
The Strong Heart Study
RICHARD B. DEVEREUX,
, MARY J. ROMAN,
, MICHAEL J. O’GRADY,
RICHARD R. FABSITZ,
, EVERETT R. RHOADES,
, ALAN CRAWFORD,
BARBARA V. HOWARD,
, ELISA T. LEE,
, AND THOMAS K. WELTY,
for the Strong Heart Study Investigators
PURPOSE: This study was undertaken to determine whether differences in left ventricular (LV) and
systemic hemodynamic ﬁndings exist between American Indians in different regions that might contrib-
ute to known differences in cardiovascular morbidity rates among American Indians.
METHODS: We compared echocardiography results in 290 non-diabetic Strong Heart Study (SHS)
participants in Arizona, 595 in Oklahoma and 572 in North/South Dakota (ND/SD).
RESULTS: Participants in the 3 regions were similar in age and gender but those in Arizona had the
highest body mass indices and lowest heart rates while those in ND/SD had the lowest diastolic blood
pressures (BP). In analyses that adjusted for signiﬁcant covariates, ND/SD participants had larger aortic
(Ao) anular, Ao root, and LV chamber size as well as higher cardiac output and lower peripheral
resistance, whereas Arizona participants had increased LV wall thickness and mass and reduced LV
myocardial contractility. These ﬁndings may contribute to the known high rates of cardiovascular events
in ND/SD Indians and to the proportionately higher rate of cardiovascular death than of non-fatal
cardiovascular events that has been recently documented in Arizona Indians.
CONCLUSIONS: Application of echocardiography to non-diabetic SHS participants reveals that LV
chamber and arterial size are larger in ND/SD Indians and that LV wall thicknesses and mass are higher
and LV myocardial contractility lower in Arizona Indians, possibly contributing to the higher than
expected rates of cardiovascular morbidity and mortality among Indians in Arizona.
Ann Epidemiol 2000;10:324–332. Published by Elsevier Science Inc.
American Indians, Echocardiography, Left Ventricle, Aorta, Cardiac Output.
and hypertension (1–4). In contrast, a community-based
mortality survey revealed that the rate of cardiovascular
The distribution of cardiovascular risk factors and the rates
death was almost as high in Arizona as in Oklahoma, both
of cardiovascular morbid events and death vary between
of which had lower cardiovascular death rates than found
American Indians in different regions of the United States
in North/South Dakota (5). A recent report (7) based on
(1–6). Previous reports from the Strong Heart Study (SHS)
systematic interpretation of electrocardiograms identiﬁed
have identiﬁed higher prevalence rates of coronary heart
substantially lower prevalence rates of deﬁnite ECG myocar-
disease in members of tribal communities in North/South
dial infarction and of all major ECG abnormalities in Indi-
Dakota and Oklahoma than in Arizona, even though resi-
ans in Arizona than in those in Oklahoma or North/South
dents in the latter area had higher rates of obesity, diabetes,
Dakota. These ﬁndings are concordant with observed differ-
ences between regions in the prevalences of clinically diag-
nosed coronary heart disease (7) but discordant with cardio-
From the New York Presbyterian Hospital-Weill Cornell Medical Cen-
vascular death rates in Arizona that were nearly equivalent
ter, New York, NY (R.B.D., M.J.R.); the University of Oklahoma Health
Science Center, Oklahoma City, OK (E.T.L., E.R.R.); Aberdeen Area
to those in the other two regions (5).
Indian Health Service, Rapid City, SD (A.C., T.K.W.); the National
Despite the important role of asymptomatic changes in
Heart Lung and Blood Institute, Bethesda, MD (R.R.F.); Johns Hopkins
cardiovascular target organs in mediating the transition from
University School of Hygiene and Public Health, Baltimore, MD (E.R.R.);
and the Medlantic Research Institute, Washington, DC (B.V.H).
risk factor exposure to the development of morbid events
Direct reprint requests to: Richard B. Devereux, MD, Division of Cardi-
(8), little systematic information is available about the possi-
ology, Box 222, The New York Presbyterian Hospital-Weill Cornell Medi-
bility that differences in objective measures of cardiovascu-
cal Center, 525 East 68th Street, New York, NY, 10021.
Received February 23, 1999; accepted March 21, 2000.
lar structure and function among groups of American Indi-
Published by Elsevier Science Inc. 1047-2797/00/$–see front matter
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