Circulation, Vol 51, 126-131, Copyright © 1975 by American Heart Association
DK Lowe, DA Rothbaum, PL McHenry, BC Corya and SB Knoebel
Thirty patients undergoing coronary cineangiography for diagnosis or
evaluation of coronary artery disease had myocardial blood flow studies pre
and post handgrip (isometric) exercise just prior to cineangiography. The
handgrip was maintained at one-third maximum effort for three minutes. The
patients also had treadmill exercise testing a day or two prior to the
study. Treadmill testing was carried out until angina or positive
ST-segment changes occurred or the patient attained 90% of predicted
maximal heart rate. Of the 30 patients, seven had no coronary artery
disease and 23 had significant disease, i.e., greater than 75% occlusion of
at least one major coronary artery. Six of the 23 patients (26%) with
disease had angina with handgrip and demonstrated a decreased myocardial
blood flow, a significantly different response from the patients without
agina (P less than 0.001). For the group without angina, the blood flow
response was not significantly different from the normal group. Treadmill
tests were positive in 19 of the 23 patients with coronary disease (83%).
The arterial systolic and diastolic pressure rise was almost identical with
the two stresses. The heart rate response, however, was significantly
different (P less than 0.001), the rate increase being greater with
treadmill exercise. The myocardial blood flow data demonstrate the relative
insensitivity of handgrip exercise for the diagnosis of coronary artery
disease. In terms of the supply demand ratio (diastolic pressure
time/systolic pressure time) concept for subendocardial perfusion, it is
possible that the difference between handgrip and treadmill stress may be
due to the different heart rate response, more rapid heart rates having a
relatively greater effect on diastolic than on systolic time indices, all
other factors being equal.
ARTICLES
Myocardial blood flow response to isometric (handgrip) and treadmill exercise in coronary artery disease
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