Effects
of age on responses
Isometric
handgrip
in noninvasive
to isometric
screening
exercise
for cardiovascular
disease
Masaya Kino, M.D.* Veronica Q. Lance, M.S.** Ahmad Shahamatpour, M.D.* David H. Spodick, M.D.*** Boston, MUSS.
Exercise stress tests have been generally used to detect cardiac malfunction. There are two basic kinds of exercise challenge which are most commonly used. One is rhythmic exercise which utilizes such equipment as a treadmill, bicycle ergometer, or set of steps and produces increased heart rate (HR), cardiac output, and systolic blood pressure with little or no increase or even decrease in diastolic blood pressure.*-” The other type, isometric exercise, usually isometric handgrip (IHG), tends to produce less increase in heart rate and cardiac output but marked increases in both systolic and diastolic pressures, usually without changing systemic vascular resistance at least in normal subjects.‘-” Because of simplicity, the IHG test has attracted the attention of the cardiologist. Isometric exercise must be performed at a grip strength sufficient to impose an acutely increased afterload on the left ventricle.5 It has been reported that systolic time intervals are sensitive enough to reflect those changes in ventricular performance produced with IHG.“-’ The present study was performed to detect any difference in responses to IHG between normal subjects and age-matched subjects with hypertensive heart disease (HHD) and coronary artery From the Cardiology Division of the Medical Services, Lemuel Shattuck Hospital. and the Department of Medicine, Tufts University School of Medicine. Boston. Mass. This investigation was supported National Heart, and Lung Institute. Iiewived Reprint Lemuel
for publication requests: Shattuck
November,
David Hospital,
by
grant
(HE136081
from
the
Oct. 12, 1974. H. Spodick, 170 Morton
M.D., Cardiology St., Boston, Mass.
1975. Vol. 90, No. 5, pp. 575-581
Division, 02130.
disease (CAD). These older normal subjects were also compared to young normal adults with regard to cardiocirculatory responses to IHG. Our aims were to assess the adequacy of IHG as a screening test for heart disease and to investigate any age-related changes. Because other investigations have demonstrated little or no change in cardiac responses at low levels of IHG,“. 9 we designed a protocol which required maximal or near-maximal IHG. Material
and methods
Studies were performed on 30 elderly male subjects who were ambulatory participants of the Framingham Heart Study and subclassified into three groups of 10 subjects each: old normals (ON; age, 54 to 78). hypertensive individuals (HHD; age, 58 to 77), and subjects with coronary artery disease (CAD; age, 59 to 79). In addition, 10 normal young male adults (“young normals” or YN; age, 23 to 31) were also studied. The old normals were those who had been normotensive and free from CAD or other disease over 22 years of periodic examination. The hypertensives were defined as subjects who had persistent cuff blood pressures exceeding 140/90 mm. Hg. Individuals in the coronary disease group had a history of myocardial infarction documented by EGG, the appropriate laboratory examinations, and/or typical angina1 attacks. No subjects had been taking cardiotonic agents. Simultaneous ECG (Lead II), phonocardiogram, and carotid pulse tracing were recorded in the supine position at a paper speed of 50 mm. per second on a Schwarzer No. 622 6 channel recorder
American,
Heari
Journal
575
Kino
Table
et al.
I. Data on entire study group Variables HR beatdmin. ON HHD CAD YN
Q-Im @sec.): ON HHD CAD YN ITT (met.): ON HHD CAD YN
IVCT @sec.): ON HHD CAD YN
PEP @sec.): ON HHD CAD YN
L VET @sec.): ON HHD CAD YN
ETI @wee.): ON HHD CAD YN
PEPfLVET: ON HHD CAD YN
Control
-C SE
P (vs. ON)
Change f SE
2.6 4.7 4.6 3.9
+11.6 +11.1 +9.8 +51.6
k -c k t
P (vs. ON)
68.3 77.1 69.0 69.4
f t -+ f
2.6 5.0 4.5 4.6
NS NS NS
80.1 88.2 78.8 120.8
52.2 44.2 53.7 60.5
k t f t
3.0 2.1 4.7 3.1
to.05 NS NS
50.8 45.1 53.1 57.5
t 3.0 r 1.4 t 5.1 f 2.6
-2.1 +0.9 -0.6 -3.0
+ + -+ f
1.9 1.7 1.1 1.3
NS NS NS
27.1 24.3 20.7 43.7
f + + +
2.6 2.1 1.3 1.4
NS < 0.05
of age on responses
Isometric
handgrip
in noninvasive
to isometric
screening
exercise
for cardiovascular
disease
Masaya Kino, M.D.* Veronica Q. Lance, M.S.** Ahmad Shahamatpour, M.D.* David H. Spodick, M.D.*** Boston, MUSS.
Exercise stress tests have been generally used to detect cardiac malfunction. There are two basic kinds of exercise challenge which are most commonly used. One is rhythmic exercise which utilizes such equipment as a treadmill, bicycle ergometer, or set of steps and produces increased heart rate (HR), cardiac output, and systolic blood pressure with little or no increase or even decrease in diastolic blood pressure.*-” The other type, isometric exercise, usually isometric handgrip (IHG), tends to produce less increase in heart rate and cardiac output but marked increases in both systolic and diastolic pressures, usually without changing systemic vascular resistance at least in normal subjects.‘-” Because of simplicity, the IHG test has attracted the attention of the cardiologist. Isometric exercise must be performed at a grip strength sufficient to impose an acutely increased afterload on the left ventricle.5 It has been reported that systolic time intervals are sensitive enough to reflect those changes in ventricular performance produced with IHG.“-’ The present study was performed to detect any difference in responses to IHG between normal subjects and age-matched subjects with hypertensive heart disease (HHD) and coronary artery From the Cardiology Division of the Medical Services, Lemuel Shattuck Hospital. and the Department of Medicine, Tufts University School of Medicine. Boston. Mass. This investigation was supported National Heart, and Lung Institute. Iiewived Reprint Lemuel
for publication requests: Shattuck
November,
David Hospital,
by
grant
(HE136081
from
the
Oct. 12, 1974. H. Spodick, 170 Morton
M.D., Cardiology St., Boston, Mass.
1975. Vol. 90, No. 5, pp. 575-581
Division, 02130.
disease (CAD). These older normal subjects were also compared to young normal adults with regard to cardiocirculatory responses to IHG. Our aims were to assess the adequacy of IHG as a screening test for heart disease and to investigate any age-related changes. Because other investigations have demonstrated little or no change in cardiac responses at low levels of IHG,“. 9 we designed a protocol which required maximal or near-maximal IHG. Material
and methods
Studies were performed on 30 elderly male subjects who were ambulatory participants of the Framingham Heart Study and subclassified into three groups of 10 subjects each: old normals (ON; age, 54 to 78). hypertensive individuals (HHD; age, 58 to 77), and subjects with coronary artery disease (CAD; age, 59 to 79). In addition, 10 normal young male adults (“young normals” or YN; age, 23 to 31) were also studied. The old normals were those who had been normotensive and free from CAD or other disease over 22 years of periodic examination. The hypertensives were defined as subjects who had persistent cuff blood pressures exceeding 140/90 mm. Hg. Individuals in the coronary disease group had a history of myocardial infarction documented by EGG, the appropriate laboratory examinations, and/or typical angina1 attacks. No subjects had been taking cardiotonic agents. Simultaneous ECG (Lead II), phonocardiogram, and carotid pulse tracing were recorded in the supine position at a paper speed of 50 mm. per second on a Schwarzer No. 622 6 channel recorder
American,
Heari
Journal
575
Kino
Table
et al.
I. Data on entire study group Variables HR beatdmin. ON HHD CAD YN
Q-Im @sec.): ON HHD CAD YN ITT (met.): ON HHD CAD YN
IVCT @sec.): ON HHD CAD YN
PEP @sec.): ON HHD CAD YN
L VET @sec.): ON HHD CAD YN
ETI @wee.): ON HHD CAD YN
PEPfLVET: ON HHD CAD YN
Control
-C SE
P (vs. ON)
Change f SE
2.6 4.7 4.6 3.9
+11.6 +11.1 +9.8 +51.6
k -c k t
P (vs. ON)
68.3 77.1 69.0 69.4
f t -+ f
2.6 5.0 4.5 4.6
NS NS NS
80.1 88.2 78.8 120.8
52.2 44.2 53.7 60.5
k t f t
3.0 2.1 4.7 3.1
to.05 NS NS
50.8 45.1 53.1 57.5
t 3.0 r 1.4 t 5.1 f 2.6
-2.1 +0.9 -0.6 -3.0
+ + -+ f
1.9 1.7 1.1 1.3
NS NS NS
27.1 24.3 20.7 43.7
f + + +
2.6 2.1 1.3 1.4
NS < 0.05
