Download Echocardiographic Evaluation ofLeft Ventricular Size

Echocardiographic Evaluation of Left Ventricular Size
and Performance During Handgrip and Supine and
Upright Bicycle Exercise
MICHAEL H. CRAWFORD, M.D., DAVID H. WHITE, M.D. AND K. WRAY AMON
SUMMARY We used M-mode echocardiography to measure left ventricular dimensions in diastole (Dd)
and systole (Ds) and to assess ventricular performance by computing the percent dimensional shortening
(%AD) and the normalized rate of dimensional shortening (Vd) during isometric and isotonic exercise in normal subjects. In 27 subjects, isometric handgrip exercise at 50% of maximum grip until fatigue produced a
significant increase in Ds (33 ± 3.4 (SD) 30.6 i 3.7 mm, p < 0.001), and a reduction in %AD (34 ± 4 vs
39 ± 5%,p < 0.001) and Vd (1.15 ± 0.15 vs 1.28 0.19 sec-',p < 0.001). Handgrip exercise at 15% of maximum grip produced similar but less marked changes in the 27 subjects, and acute pressure loading with
phenylephrine caused similar but more marked changes in 10 of the subjects. In the 20 subjects who performed
at least 12 minutes of supine bicycle exercise, Ds decreased significantly (25.6 ± 4.0 vs 31.7 ± 2.8 mm,
p < 0.001) and %AD increased (49 ± 6 vs 36 ± 5%,p < 0.001). We observed similar results in the 12 subjects
also studied during upright bicycle exercise. Dd was smaller in the upright position but unchanged during
either isometric or isotonic exercise. We conclude that: 1) end-diastolic left ventricular size is maintained during isometric exercise and moderate dynamic exercise, even in the upright position; 2) isometric exercise leads
to a mild decrease in left ventricular shortening, whereas dynamic exercise results in marked increases in
shortening; this difference may be related to the relatively greater increase in blood pressure than in heart rate
during isometric exercise; and 3) M-mode echocardiography can be successfully accomplished in selected subjects during various forms of exercise.
vs
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to subject, but none could be considered a trained
athlete. We obtained written informed consent from
each subject on a form approved by the Institutional
Review Board of the University of Texas Health
Science Center at San Antonio. All the exercise
studies were performed 6 or more hours after eating.
M-MODE ECHOCARDIOGRAPHY is an accurate
and reproducible technique for assessing resting left
ventricular size and performance in normal-sized
hearts without segmental myocardial disease.'14 The
sensitivity of this technique for detecting changes in
left ventricular dynamics has been shown in studies
evaluating the response to upright tilting,', the Valsalva maneuver,7 8 ventricular premature depolarizations,9 normal phasic respiration'0 and acute pharmacologic interventions with agents such as amyl
nitrite, nitroglycerin, atropine and phenylephrine.1" 12
One advantage of echocardiography is the ability to
measure left ventricular diameters intermittently or
continuously before, during and after an intervention
without risk or discomfort to the subject and without
affecting the normal response to the test conditions.
Accordingly, we used echocardiography to measure
left ventricular size and performance in normal subjects during isometric handgrip exercise and dynamic
bicycle exercise in the supine and upright positions.
Handgrip Exercise
All 27 subjects performed isometric handgrip exercise in the supine position using a hand-held, adjustable dynamometer (Stoelting Co.). Maximum
isometric grip was determined as the best of three
attempts. The subjects then held 15% of their maximum grip until the point of fatigue, at which time
blood pressure (cuff sphygmomanometer) and echocardiograms were recorded when the subject indicated
that he could exercise for 30 seconds more. After a 15minute rest, the subjects performed 50% maximum
grip to fatigue, then blood pressure and echocardiograms were recorded during the last 30 seconds of exercise.
Methods
The study population consisted of 27 normal subjects who were selected from a group of twice as many
because of excellent echocardiograms in the supine
position at rest. There were 23 men and four women,
ages 19-36 years. Physical fitness varied from subject
Acute Pressure Loading
On another day, 10 of the 27 subjects participated in
an acute pressure loading study. With the patient in
the supine position, we gave 1.5 mg of atropine intravenously, followed by an intravenous drip of phenylephrine (10 mg in 250 ml of normal saline) until
systolic blood pressure was approximately 40 mm Hg
higher than the basal level. Then, we recorded the
echocardiograms and stopped the infusion. The total
fluid volume infused was less than 50 ml.
From the Cardiology Division, Department of Medicine, University of Texas Health Science Center, San Antonio, Texas.
Supported by the Medical Research Service of the Veterans Administration.
Address for reprints: Michael H. Crawford, M.D., Director, Cardiac Noninvasive Diagnostic Laboratories, University of Texas
Health Science Center; 7703 Floyd Curl Drive, San Antonio, Texas
Bicycle Exercise
78284.
Received October 6, 1978; revision accepted January 3, 1979.
Circulation 59, No. 6, 1979.
Twelve of the 27 subjects had adequate echocardiograms recorded in the upright position, and these sub1188
LV SIZE AND PERFORMANCE/Crawford et al.
jects performed upright bicycle exercise on a different
day using a Monark Bicycle Ergometer. Bicycle exercise was begun at 150 kilopond-meters (kpm)/min and
was increased by 150 kpm/min every 3 minutes. We
studied 20 subjects - the 12 who performed upright
exercise and eight additional normal subjects (four
men and four women) - during supine bicycle exercise on a Quinton Uniwork Ergometer, model 844.
Exercise was begun at 200 kpm/min and was increased by 100 kpm/min every 3 minutes. Before exercise in the cycling position (feet upon pedals) and during the last 30 seconds of each 3-minute stage, we
recorded blood pressure and echocardiograms. Exercise endurance varied in these untrained subjects.
Supine exercise lasted 12-30 minutes (mean 17.5) and
upright exercise 9-18 minutes (mean 13.5).
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Echocardiography
We obtained echocardiograms using either a Picker
Echoview 80-C coupled to an Irex Continutrace 101
recorder or an Electronics for Medicine Echo IV
system. Echocardiograms of the left ventricle were
taken from the standard intercostal space'3 along the
left sternal border with a hand-held transducer (2.25
MHz) and were recorded on a strip-chart recorder at
100 mm/sec paper speed. Using the R wave of the
simultaneously recorded ECG as the reference point,
we measured end-diastolic dimension (Dd) of the left
ventricle at the level of the chordae tendineae. We
measured the end-systolic dimension (Ds) as the
smallest dimension between the left septal endocar-
1189
dium and the posterior wall endocardium during
systole whether or not the two walls were exactly apposed.'4 We also recorded simultaneous indirect
carotid pulse tracings during isometric exercise and
the acute pressure loading studies in order to measure
left ventricular ejection time (ET). We calculated the
heart rate from the simultaneously recorded ECG. All
echocardiograms were performed with the subject in
the same position, with the hand-held transducer in
the same interspace and when the same anatomic
landmarks were present. The echocardiographic
measurements were made during expiration'0 and
represent the average of at least three heart beats.
Figure 1 shows three echocardiograms for the same
subject recorded at rest sitting on the bicycle, after 9
minutes of upright exercise and after 15 minutes of upright exercise. The ECG at the top of each echo indicates the increasing heart rate; the anatomic landmarks are identical in each recording.
From the echocardiographic measurements described above, the percent left ventricular dimension
shortening (%AD) and the normalized mean rate of
left ventricular dimension shortening (Vd) were calculated as follows:
Dd Ds
vd
Statistical Analysis
We compared the subject's resting values and those
attained at a certain point during exercise (see below)
B
A
Dd -Ds
Dd X ET
c
I
Ona-
--A--
ECG
,,,,_,
C_w 1
__.
=g
.Z=
I
-- 2
a,-e
lR
FIGURE 1. Left ventricular echograms at 100 mm/sec
paper speed from a subject who performed upright bicycle
exercise. A) At rest on the bicycle; B) during the ninth
minute of exercise; C) during the fifteenth minute of exercise. ECG = electrocardiogram; Dd left ventricular enddiastolic dimension; Ds end-systolic dimension (see text).
=
VOL 59, No 6, JUNE 1979
CIRCULATION
1190
using the paired t test; each subject served as his or her
own control. Some subjects repeated the exercise
studies 1-7 days later at the same time of day, and we
compared the measurements at each stage of exercise
between the two days using the paired t test.
Results
Handgrip Exercise (fig. 2)
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At 15% of maximum grip, a modest but statistically
significant increase in heart rate from 65 ± 10 (SD) to
70 ± 10 beats/min (p < 0.001) was observed in the 27
subjects. Systolic blood pressure also increased
significantly from 110 ± 11 to 123 ± 12 mm Hg
(p < 0.001). Left ventricular Dd was unchanged, but
Ds increased significantly from 30.6 ± 3.7 to
31.7 ± 3.5 mm (p < 0.01) and %AD decreased
significantly from 39 ± 5 to 36 ± 5% (p < 0.01). Vd
also decreased from 1.28 ± 0.19 to 1.19 ± 0.16 sec-1
(p < 0.01).
During handgrip exercise at 50% of maximum grip,
heart rate was significantly higher than the control
(79 ± 10 vs 65 ± 10 beats/min, p < 0.001), as was
systolic blood pressure (139 ± 16 vs 110i 1 1 mm
Hg, p < 0.001). Dd remained unchanged, but Ds increased (33 ± 3.4 vs 30.6 ± 3.7 mm, p < 0.001) and
%AD was reduced (34 ± 4 vs 39 ± 5%, p < 0.001).
Also, Vd decreased (1.15 ± 0.15 vs 1.28 ± 0.19 sec'1,
p < 0.001).
Five subjects repeated the handgrip exercise on
another day under similar conditions. Individual
values between the two studies varied somewhat, but
the overall response to isometric exercise was the
same. Mean heart rate, systolic blood pressure, %zAD,
and Vd were not statistically different between the two
studies at rest or during 15% and 50% maximal grip
(table 1).
Acute Pressure Loading (fig. 3)
Ten of the 27 subjects who performed handgrip exercise were also given atropine and phenylephrine at
another time for comparative purposes. This pharmacologic combination increased heart rate from
65 ± 7 to 91 ± 18 beats/min (p < 0.01) and augmented systolic blood pressure from 109 ± 5 to
157 ± 9 mm Hg (p < 0.001). Dd was unchanged, but
Ds increased significantly from 31.1 ± 2.4 to
35.4 ± 3.4 mm (p < 0.001) and %AD decreased
significantly from 38 ± 4 to 31 ± 5% (p < 0.001). Vd
also fell significantly from 1.26 ± 0.16 to 1.07 ± 0.24
sec-1 (p < 0.01).
Supine Bicycle Exercise (fig. 4)
The 20 subjects who performed supine bicycle exercise pedaled for at least 12 minutes. During each exercise load, heart rate and systolic blood pressure increased progressively, but for statistical purposes the
control state was compared with 12 minutes of exer-
T=+ ISD
p<.001
90
C
*
80
E
m
0
E
E
a70
60
I
a.
3o
0
0-
(0
c')
6050-
m
0
c-
to
0
~w0
0
I')
0"
0--
Ifle
I')
FIGURE 2. Effect of handgrip exercise at 15 and 50% of maximum voluntary contraction to the point of
fatigue on heart rate (HR), systolic blood pressure (SBP), percent left ventricular minor dimension shortening (%,AD) and mean normalized rate of dimensional shortening (Vd) in 27 normal subjects.
LV SIZE AND PERFORMANCE/Crawford et al.
TABLF, 1. Repeat Handgrip Exercise Studies in Five Subjects
HtR beats/min
B
50%
15%
62 13
75 9
57 9
Sttudy 1
Study 2
66 -11
69 ='11
77 =9
B
109 11
104 =4
(cAl)
13%,
B
Study 1
Study 2
38
38
4
4
34
34
50%-/
34
33
7
7
B
1.21
0.22
1.28 f 0.20
4
4
SBP mm Hg
i5%7
119 11
120 -7
Vd
1 5%c
0.22
1.09
1.13 - 0.18
1 191
50%c
135
135
20
7
5 0%
1.11
1.15
0.18
0.25
Abbreviations: HlR = heart rate; SBP = systolic blood pressure; %oADI) = percent left ventricular minor
dimenision shortening; Vd = normalized mean rate of left ventricular dimension shortening; B = baseline.
12 minutes of supine exercise were not statistically
different between the two exercise studies. The comparative data for Dd, Ds and %zAD are shown in
figure 5.
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cise, so that all the subjects could be included in the
analysis.
During the twelfth minute of exercise, heart rate
had increased from 66 ± 9 to 124 ± 13 beats/min
(p < 0.001), and systolic blood pressure had risen from
108 ± 4 to 153 ± 13 mm Hg (p < 0.001). Dd was not
changed (49.8 + 4.0 vs 50.3 ± 4.5 mm, p > 0.05). Ds
decreased significantly from 31.7 ± 2.7 to 25.6 ± 4.0
mm (p < 0.001) and %AD increased from 36 ± 4 to
49 ± 4% (p < 0.001).
Eleven of these 20 subjects repeated supine bicycle
exercise on another day under similar conditions. All
11 subjects again completed at least 12 minutes of exercise; four increased their exercise duration by one
stage (3 minutes); one subject's tolerance decreased by
one stage; and the remaining six completed the same
amount of exercise. The heart rate, systolic blood
pressure, Dd, Ds, and %/D at rest and at 3, 6, 9, and
Upright Bicycle Exercise (fig. 6)
The 12 subjects completed at least 9 minutes of upright pedaling. Therefore, the values during the ninth
minute of exercise were selected for group statistical
analysis. In general, the results were quite comparable
to those obtained during supine exercise except that
the resting values were different in the upright position.
During the ninth minute of exercise, heart rate had
increased from 72 + 14 to 126 ± 21 beats/min
(p < 0.001) and systolic blood pressure had risen from
106 ± 10 to 141 ± 11 mm Hg (p < 0.001). A small
.
T=+ ISD
* p<.001
* p<.OI
90-
16050-
80-
I
40-
40-1
T
1.30-
E
E 130-
z
a.
a
Cl)
70-
30-
120-
a
T
120-
110-
60-'
1oo
I
1.00-_
20-_
0 +
0
+
0I+
FIGURE 3. Effect of intravenous atropine
and phenylephrine (A +P) on heart rate
(HR), systolic bloodpressure (SBP), percent
left ventricular minor dimension shortening
(%zAD) and mean normalized rate of dimensional shortening ( Vd) in 10 normal subjects.
VOL 59, No 6, JUNE 1979
CIRCULATION
1192
T= + ISD
* p<.001
*
120Dd
*
._a
110-
50-
100-
40C0~
I
E
E
o 90-
a.
en
I
E
E
a
a
04~
30-
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80-
20-
70-
10-I
60-
g
-
c
U)
a
a,
0
Er
0
E
N
N
c%j
N
.C
<;
.s
N
0Co
C0
a:
c
CQ
E
N
FIGURE 4. Effect of 12 minutes of graded supine bicycle exercise on heart rate (HR), systolic blood
pressure (SBP), left ventricular end-diastolic (Dd) and end-systolic (Ds) dimension and percent left ventricular minor dimension shortening (%,AD) in 20 normal subjects.
(p < 0.001) and %AD increased from 38 + 6 to
51 ± 6 (p <0.001).
Five of the 12 subjects repeated upright bicycle ex-
rise in Dd was not statistically significant (46.5 ± 3.6
vs 48.9 ± 5.7 mm, p > 0.05). Ds decreased
significantly from 29.1 ± 3.8 to 24.2 + 4.4 mm
50-
-60
Dd
Dd
-55
% AD
40-
- 50
- 45
E
E
%R
30-
Ds
- 40
%AD
-
35
Ds
20 -
T-+ ISD
*=
A=
-30
Study # I
Study #2
I
I
Rest
3
min
25
I
6
min
9
min
12
min
FIGURE 5. Comparison of left ventricular
end-diastolic (Dd) and end-systolic (Ds)
dimension and percent left ventricular minor
dimension shortening (%AD) during 12
minutes of supine bicycle exercise on two
different days in 11 normal subjects.
LV SIZE AND PERFORMANCE/Crawford et al.
I
120-
110 -
100-
1193
T=+ ISD
* p<.001
._a
0
a
0
90-
I
.0
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I
E
E
E
E
0
0
a-
80-
m
cn
11
70
0
10
10-
|
10
|
60o
._
ir
E
O
._
*-
C
E
E
E
E
a)
O
zn
a)~~~)
._en
FIGURE 6. Effect of 9 minutes of graded upright bicycle exercise on heart rate (HR), systolic blood
pressure (SBP), left ventricular end-diastolic (Dd) and end-systolic (Ds) dimension, and percent left ventricular minor dimension shortening (%AD) in 12 normal subjects.
ercise on another day and their exercise duration was
unchanged (one 12 minutes, four 15 minutes). Individual values at each stage between the two studies
varied somewhat, but the overall response to exercise
was the same. Mean heart rate, systolic blood
pressure, Dd, Ds and %zAD were not statistically
different between the two studies at rest, nor at 3, 6, 9,
and 12 minutes of exercise (table 2).
Discussion
The circulatory response to handgrip exercise is
complex and partly dependent on the severity of the
handgrip stress.'" The general response to isometric
exercise is similar to that of any type of exercise and
consists of an increase in heart rate, blood pressure
and cardiac output. However, in contrast to other
forms of exercise, at 50% or greater of maximum
voluntary contraction, stroke volume has been noted
TABLE 2. Repeat Upright Exercise Studies in Five Subjects
Dd (mm)
6 min
12 min
Rest
Rest
- 3.3
46.2
48.6
-4.0
4.6
=±3.9
29.4
49.8
1
Study
30.6
3.6
Study 2 47.7 2.4 49.9 2.2 49.3 3.0
to decrease.16' 17 Our results, using echocardiography
to measure the left ventricular internal dimensions,
are in agreement with these findings. We saw a
diminution in %AD and Vd during handgrip exercise,
which was most marked at 50% of maximal voluntary
contraction.
There are few previous data concerning changes in
end-diastolic volume during handgrip exercise. In five
normal persons studied with a plain radiographic
technique, the cardiac silhouette decreased during 15%
maximum voluntary grip.'8 A recent cineangiographic study evaluated six normal persons during a
30% maximum voluntary grip and showed a decrease
in end-diastolic volume.'9 An earlier echocardiographic study using the Polaroid technique showed no
change in Dd during 50% of maximal grip in 20 normal subjects.20 Our results showed no significant
change in Dd at the point of fatigue at either 15% or
50% of maximum grip. Therefore, the results of the
__A_D
Ds (mm)
12 min
6 min
6 min
12 min
Rest
52 7
48 7
26.2 -3.6 23.2 d4.1
37 =7
54 =4
46 - 5
26.8 - 3.0 20.6 - 3.2
36 - 7
Abbreviations: Dd = left ventricular end-diastolic dimension; Ds = left ventricular end-systolic dimension; %AD = percent
left ventricular minor dimension shortening.
_
_
_
1194
CIRCULATION
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radiographic and echocardiographic studies differ.
There are certain methodological problems with the
radiographic studies. The plain radiographic technique does not accurately distinguish the left ventricle
from the rest of the cardiac silhouette. Also,
cineangiographic contrast material injected for the
control angiographic study may affect left ventricular
size and performance and modify the subsequent
response to isometric exercise. However, the response
to handgrip exercise is complex and the smaller
number of subjects in the two radiographic studies (11
total) than in the echocardiographic studies (47 total)
may be a more important factor in explaining the
differences than methodological problems.
Studies in animals21 and man'2 have shown that
acute pharmacologic pressure loading results in a
decrease in Vd. Our results with handgrip exercise at
50% maximal grip show a reduction in left ventricular
performance which was similar to that produced by intravenous atropine and phenylephrine in 10 of the subjects. These findings support the theory that isometric
exercise represents an afterload stress to the left ventricle. Acute pharmacologic afterloading has been
used in a variety of studies to assess left ventricular
reserve in disease states22, 23 and after therapeutic
agents.24' 25 Strenuous handgrip exercise seems to accomplish the same result, is simple to perform in
cooperative patients, and may represent a more
"'physiologic" approach to the evaluation of left ventricular functional reserve.
In animals, studies using endocardial echo crystals
inserted surgically across the left ventricular chamber
for the continuous measurement of diameter have
shown a progressive decrease in Ds during dynamic
exercise which corresponds to an increase in stroke
volume.26 28 Human studies using surgically placed
epicardial lead markers fluoroscopically visualized
during bicycle exercise have also demonstrated a
decrease in the distance between the clips at end-
c
+100
-
+80
-
+60
-
E
0
+40-
+20-
graded bicycle exercise.
0'
CP
a)
systole with progressive exercise.29 Also, studies using
left ventricular contrast angiography30 and radionuclide angiography3" have shown a decrease in endsystolic volume at maximum bicycle exercise. Our
results are in agreement with these findings and support the concept that increases in stroke volume are an
important part of the normal response to isotonic exercise.
Controversy exists concerning left ventricular enddiastolic volume during dynamic exercise. Animal
studies using implanted subendocardial echo crystals
showed no change in end-diastolic diameter during
mild-to-moderate exercise, but an increase during
severe exercise.2628 Also, in a recent study using
radionuclide angiography during submaximal upright
bicycle exercise (85% of maximum predicted heart
rate), two-thirds of the subjects exhibited a modest increase in end-diastolic volume and the mean difference
was statistically different (p < 0.02).3' However, the
resting data were done 10-30 minutes after the exercise study. By contrast, human studies using angiography and epicardial clips have demonstrated a 5-10%
decrease in Dd during moderate supine exercise.29 30
Our results showed no significant change in Dd during moderate supine or upright bicycle exercise. The
inability of echocardiography to detect consistent
changes in Dd during exercise may represent a
technical sensitivity problem or could be related to the
submaximal amount of exercise performed by most of
our subjects. Four of our subjects achieved what could
be considered severe isotonic exercise (heart
rate > 170 beats/min), but there was no consistent
difference in Dd.
The sensitivity of the external echocardiographic
technique for assessing change in left ventricular size
is demonstrated by comparing the resting Dd supine
and upright (on the bicycle) in the 12 subjects who performed both types of exercise. Resting Dd supine was
50.9 ± 4.2, significantly larger than the Dd upright of
FIGURE 7. Percent change in heart rate
(HR), systolic blood pressure (SBP), and
percent left ventricular minor dimension
shortening (%AD) from rest to handgrip exercise at 50% of maximum grip (HG) and to
9 minutes of supine (SUP) and upright (UP)
0
cr
VOL 59, No 6, JUNE 1979
0
0
I
-20 -
tL
D
cn
HR
L-
D
LV SIZE AND PERFORMANCE/Crawford et al.
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47.0 ± 3.3 (p < 0.01). This difference persisted during exercise but was less marked. Six of these 12 subjects had more than a 2-mm change in Dd between the
upright resting recording and the 3 minutes of exercise
recording and in all six the change was an increase in
Dd (+ 2.7 to 6.8 mm). These findings support the concept that the activation of the leg muscles at the onset
of upright cycling initially augments left ventricular
end-diastolic volume. Such changes during the first 3
minutes of exercise were not seen in the supine position where, presumably, venous return is near maximum at rest.
There are potential problems with external echocardiography during exercise. Even though we very
carefully recorded the resting tracings in the position
in which the exercise was to be performed, used the
same transducer position for each recording, recorded
only when the same anatomic landmarks were present, and analyzed only the beats recorded during the
same phase of respiration as the resting tracing,
changes in heart position during exercise could have
occurred and influenced our results. We noted small
changes in left ventricular size and performance in
some of the subjects who repeated the exercise studies
which may have been due to spontaneous alterations
in sympathetic tone, a training effect, etc., but the
directional changes in Dd, Ds and %AD with each
form of exercise were always the same.
A comparison of the hemodynamic response to
isometric and dynamic exercise may partly explain
their opposite effect on left ventricular performance.
Figure 7 shows the percent change in heart rate,
systolic blood pressure and %AD during isometric
handgrip exercise at 50% of maximum grip and 9
minutes of supine and upright bicycle exercise. Heart
rate increases much more during dynamic exercise
than during isometric exercise, yet the increases in
blood pressure are similar. Therefore, isometric exercise produces a relatively greater increase in blood
pressure than in heart rate that may result in sufficient
afterload stress to account for the decrease in left ventricular performance.
This study shows that M-mode echocardiograms of
the left ventricle can be successfully recorded in
selected subjects during various types of exercise.
These results in normal subjects form a basis for
evaluating differences in the response of the left ventricle to exercise in disease states and under the influence
of cardioactive drugs. For example, if a patient has
compensated cardiac function at rest, left ventricular
size and performance indices could be normal, but
during the stress of exercise an abnormal response
may be detected. Preliminary data suggest that twodimensional echocardiographic studies can also be
performed during exercise, which should be of more
value in patients with segmental myocardial disease.
Acknowledgment
The advice and encouragement of Dr. Robert A. O'Rourke is
greatly appreciated.
1195
References
1. Pombo JF, Troy BL, Russel RO Jr: Left ventricular volumes
and ejection fraction by echocardiography. Circulation 43: 480,
1971
2. Fortuin NJ, Hood WP, Sherman ME, Craige E: Determination
of left ventricular volumes by ultrasound. Circulation 44: 575,
1971
3. Quinones MA, Gaasch WH, Alexander JK: Echocardiographic assessment of left ventricular function with special
reference to normalized velocities. Circulation 50: 41, 1974
4. Henning H, Schelbert H, Crawford MH, Karliner JS, Ashburn
W, O'Rourke RA: Left ventricular performance assessed by
radionuclide angiocardiography and echocardiography in
patients with previous myocardial infarction. Circulation 52:
1069, 1975
5. Redwood DR, Henry WL, Epstein SE: Evaluation of the ability
of echocardiograpby to measure acute alterations in left ventricular volume. C'irculation 50: 901, 1974
6. Rankin LS, Moos S, Grossman W: Alterations in preload and
ejection phase indices of left ventricular performance. Circulation 51: 910, 1975
7. Parisi AF, Harrington JJ, Askenazi J, Pratt RC, McIntyre
KM: Echocardiographic evaluation of the Valsalva maneuver
in healthy subjects and patients with and without heart failure.
Circulation 54: 921, 1976
8. Robertson D, Stevens RM, Friesinger GC, Oates JA: The effect
of the Valsalva maneuver on echocardiographic dimensions in
man. Circulation 55: 596, 1977
9. Cohn PF, Angoff GH, Zoll PM, Sloss LJ, Markis JE, Graboys
TB, Green LH, Braunwald E: A new, noninvasive technique for
inducing postextrasystolic potentiation during echocardiography. Circulation 56: 598, 1977
10. Brenner JI, Waugh RA: Effect of phasic respiration on left ventricular dimension and performance in a normal population. An
echocardiographic study. Circulation 57: 122, 1978
11. Burggraf GW, Parker JO: Left ventricular volume changes
after amyl nitrite and nitroglycerin in man as measured by ultrasound. Circulation 49: 136, 1974
12. Hirshleifer J, Crawford M, O'Rourke RA, Karliner JS:
Influence of acute alterations in heart rate and systemic arterial
pressure on echocardiographic measures of left ventricular performance in normal human subjects. Circulation 52: 835, 1975
13. Popp RL, Filly K, Brown OR, Harrison DC: Effect of
transducer placement on echocardiographic measurements of
left ventricular dimensions. Am J Cardiol 35: 537, 1975
14. Cooper RH, O'Rourke RA, Karliner JS, Peterson KL,
Leopold GR: Comparison of ultrasound and cineangiographic
measurements of the mean rate of circumferential fiber shortening in man. Circulation 46: 914, 1972
15. Lind AR, McNicol GW: Local and central circulatory
responses to sustained contractions and the effect of restricted
arterial inflow on postexercise hyperaemia. J Physiol 192: 575,
1967
16. Donald KW, Lind AR, McNicol GW, Humphreys PW, Taylor
SH, Staunton HP: Cardiovascular responses to sustained
(static) contractions. Circ Res 20 (suppl I): 1-15, 1967
17. Payne RM, Horwitz LD, Mullins CB: Comparison of isometric
exercise and angiotensin infusion as stress test for evaluation of
left ventricular function. Am J Cardiol 31: 428, 1973
18. Ludbrook P, Karliner JS, O'Rourke RA: Effects of submaximal isometric handgrip on left ventricular size and wall
motion. Am J Cardiol 33: 30, 1974
19. Flessas AP, Connelly GP, Handa S, Tilney CR, Kloster CK,
Rimmer RH, Keefe JF, Klein MD, Ryan TJ: Effects of
isometric exercise on the end-diastolic pressure, volumes and
function of the left ventricle in man. Circulation 53: 839, 1976
20. Stefadouros MA, Grossman W, El Shahawy M, Stefadouros F,
Witham AC: Noninvasive study of effect of isometric exercise
on left ventricular performance in normal man. Br Heart J 36:
988, 1974
21. Mahler F, Ross J Jr, O'Rourke RA, Covell JW: Effects of
changes in preload, afterload and inotropic state on ejection and
isovolumic phase measures of contractility in the conscious dog.
Am J Cardiol 35: 626, 1975
1196
CIRCULATION
22. Krovetz LJ, McLoughlin TG, Schiebler GL: Left ventricular
function in children studied by increasing peripheral resistance
with angiotensin. Circulation 37: 729, 1968
23. Ross J Jr, Braunwald E: The study of left ventricular function
in man by increasing resistance to ventricular ejection with
angiotensin. Circulation 29: 739, 1964
24. Mahler F, Karliner JS, O'Rourke RA: Effects of chronic digoxin administration on left ventricular performance in the normal
conscious dog. Circulation 50: 720, 1974
25. Crawford MH, Karliner JS, O'Rourke RA: Favorable effects
of oral maintenance digoxin therapy on left ventricular performance in normal subjects: echocardiographic study. Am J Cardiol 38: 843, 1976
26. Erickson HH, Bishop VS, Kardon MB, Horwitz LD: Left ventricular internal diameter and cardiac function during exercise.
J Appl Physiol 30: 473, 1971
VOL 59, No 6, JUNE 1979
27. Horwitz LD, Atkins JM, Leshin SJ: Role of the Frank-Starling
mechanism in exercise. Circ Res 31: 868, 1972
28. Vatner SF, Franklin D, Higgins CB, Patrick T, Braunwald E:
Left ventricular response to severe exertion in untethered dogs.
J Clin Invest 51: 3052, 1972
29. Braunwald E, Goldblatt A, Harrison DC, Mason DT: Studies
on cardiac dimensions in intact unanesthetized man. III. Effects
of muscular exercise. Circ Res 13: 460, 1963
30. Sharma B, Goodwin JF, Raphael MJ, Steiner RE, Rainbow
RG, Taylor SH: Left ventricular angiography on exercise: a
new method of assessing left ventricular function in ischaemic
heart disease. Br Heart J 38: 59, 1976
31. Rerych SK, Scholtz PM, Newman GE, Sabiston DC, Jones
RH: Cardiac function at rest and during exercise in normals
and in patients with coronary heart disease: evaluation by
radionuclide angiocardiography. Ann Surg 187: 449, 1978
Measurement of Left Ventricular Ejection Fraction
Downloaded from http://circ.ahajournals.org/ by guest on June 17, 2017
by Mechanical Cross-Sectional Echocardiography
KENNETH W. CARR, M.D., ROBERT L. ENGLER, M.D., JOHN R. FORSYTHE, R.D.M.S.,
ALLEN D. JOHNSON, M.D., AND BARBARA GOSINK, M.D.
SUMMARY Cross-sectional echocardiography is a new noninvasive technique for imaging the heart. We
developed a method for using mechanical cross-sectional echocardiograms (sector scans) to determine left ventricular volumes and ejection fraction. Using left ventricular cineangiography as a standard, sector scan ejection fraction correlated better (r = 0.93) than M-mode echocardiography by any of three established methods,
and the sector scan regression line did not differ from the line of identity (p > 0.33). Interobserver variability
for sector scan ejection fraction was 2.3 i 1.2% (mean ± SD). Variation between two studies performed
within 24 hours and analyzed by the same observer was 1.4 ± 1.5%. However, the sector scans consistently underestimated left ventricular end-diastolic volume. We conclude that sector scan echocardiography is more
reliable than conventional M-mode techniques for estimating left ventricular ejection fraction, but estimation
of left ventricular end-diastolic volume is unreliable with the methods currently available.
M-MODE ECHOCARDIOGRAPHY is useful for
evaluating left ventricular performance and measuring
left ventricular volume in patients without regional
myocardial dysfunction.12 However, the presence of
regional wall motion disorders has limited the
reliability of the single-chord technique for determining ejection fraction.'3 '5 Mechanical crosssectional echocardiography is a new technique which
can image the left ventricle in four planes by using a
standard echocardiographic transducer mechanically
swept at 60 Hz through an arc of adjustable width."'
We applied the techniques of left ventricular angiographic analysis to cross-sectional echocardiograms
(sector scans) and developed a method for determinFrom the Division of Cardiology, Department of Medicine, and
the Ultrasound Section, Department of Radiology, San Diego
Veterans Administration Hospital and the University of California,
San Diego School of Medicine, San Diego, California.
Address for reprints: Robert L. Engler, M.D., Veterans Administration Hospital-il lA, La Jolla Village Drive, San Diego,
California 92161.
Received June 12, 1978; revision accepted December 14, 1978.
Circulation 59, No. 6, 1979.
ing left ventricular ejection fraction and end-diastolic
volume. In this study we assessed the comparative
value of cross-sectional echocardiography and Mmode echocardiography for determining ejection fraction and end-diastolic volume in an unselected group
of patients, using left ventricular cineangiography as
the reference standard.
Methods
Contrast Angiography
Twenty-four patients who underwent routine cardiac catheterization and left ventriculography were
studied.
All cardiac medications (digitalis, diuretics,
propranolol and nitrates) were withheld for at least 10
hours, and patients were fasting the morning of
catheterization. Biplane left ventriculograms were
performed before coronary angiography. Cineangiograms were recorded simultaneously from the 150
right anterior oblique and 750 left anterior oblique
views at 58 to 61 frames/sec. The first well-opacified
sinus beat after a sinus beat was selected for analysis.
In four patients with atrial fibrillation a supraven-
Echocardiographic evaluation of left ventricular size and performance during handgrip
and supine and upright bicycle exercise.
M H Crawford, D H White and K W Amon
Downloaded from http://circ.ahajournals.org/ by guest on June 17, 2017
Circulation. 1979;59:1188-1196
doi: 10.1161/01.CIR.59.6.1188
Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231
Copyright © 1979 American Heart Association, Inc. All rights reserved.
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