Circulation, Vol 56, 989-996, Copyright © 1977 by American Heart Association
M Nemati, D McCaughan, JT Doyle and HV Pipberger
Correlations between 276 orthogonal electrocardiographic measurements and
constitutional variables were made in 450 normal women, aged 18 to 90
years. Advancing age led to decreases in amplitudes, left QRS axis shift,
rightward and superior displacement of the ST segment, and anterior shift
of the T wave. QZ was absent in 1% of normal women over age 40. In the
oldest subjects, Ry amplitude was 71% and RZ amplitude was 80% of the
respective values in the youngest group. Whereas QRS amplitude decreases
with age leveled off at the sixth decade of life, they continued to old age
for ST-T measurements. Men revealed steeper age trends than women. Blacks
had larger QRS amplitudes and smaller Q/R ratios than whites.
Stratification of electrocardiographic criteria according to age, sex, and
race appears essential for routine interpretations and for epidemiological
studies where new events, such as myocardial infarcts, need to be
differentiated from normal age trends.
ARTICLES
The influence of constitutional variables on orthogonal electrocardiograms of normal women
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