Download Cross-sectional Area of the Proximal Portions of the

Cross-sectional Area of the Proximal Portions of the
Three Major Epicardial Coronary Arteries in 98
Necropsy Patients with Different Coronary Events
Relationship to Heart Weight, Age and Sex
CHARLES S. ROBERTS
AND
WILLIAM C. ROBERTS, M.D.
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SUMMARY The cross-sectional area (the portion enclosed by the internal elastic membrane) of histologic
sections from the first 5-mm long segments of the right, left anterior descending and left circumflex coronary
arteries was determined by videoplanimetry in 98 necropsy patients with coronary heart disease and in 46 control subjects who did not have significant coronary narrowing. Significant (p < 0.001) differences were
observed in the mean cross-sectional area of each of the three major coronary arteries in the subgroups of coronary patients and among and between the control subjects. These differences resulted primarily from
differences in heart weight and, to a slight extent, in age. Difference in sex was not significant. The 20 patients
with angina pectoris had the smallest coronary arteries (mean cross-sectional area of each of the 60 arteries
6.0 mm2) and the smallest hearts (mean weight 386 g). The 18 patients with healed myocardial infarcts and intractable congestive heart failure had the largest coronary arteries (mean area 8.6 mm') and the largest hearts
(mean weight 588 g). The 23 patients with acute transmural myocardial infarcts and the 19 with sudden coronary death had similar-sized coronary arteries (mean area 7.6 mm') and similar-sized hearts (mean weight
471 g). The 18 patients with healed myocardial infarcts, subsequently asymptomatic courses and noncardiac
deaths had slightly enlarged arteries (mean area 6.9 mm') and hearts (mean weight 430 g). The 31 control subjects with cancer and normal or near-normal-sized hearts (mean weight 309 g) had the smallest coronary
arteries (mean area 5.0 mm'). The 16 controls with aortic valve disease had the largest hearts (mean weight
730 g) and the largest coronary arteries (mean area 9.6 mm'). When heart weights were equalized (450 g),
older patients had larger coronary arteries than younger patients (mean area < 40 years 6.5 mm', 41-60 years
6.8 mm' and > 60 years 7.6 mm').
can flow in the smaller artery (fig. 1). In the present
study, therefore, we describe the sizes of the three major coronary arteries in necropsy patients with clinical
evidence of coronary heart disease and in control subjects and examine whether the sizes of these arteries
are similar or different in various subgroups of coronary patients and, if different, why.
DEGREES of coronary arterial luminal narrowing in
patients with symptomatic or fatal coronary heart disease have been studied extensively in recent years. The
degrees of coronary narrowing in necropsy patients
with fatal coronary heart disease are usually recorded
in terms of cross-sectional area. Studies from this
laboratory and others indicate that patients with fatal
coronary heart disease at necropsy usually have
narrowing by atherosclerotic plaques of more than
75% in cross-sectional area of at least two of the three
major (right, left anterior descending and right)
epicardial coronary arteries, and that over 30% of the
entire lengths of these three major arteries are
narrowed to this extent.1-7 Although degrees of crosssectional area narrowing at necropsy of the major
epicardial coronary arteries have demonstrated certain differences among subsets of patients with fatal
coronary heart disease,3-7 cross sectional area does not
provide complete anatomic information. A large
artery and a small artery, for example, can be
similarly narrowed in cross-sectional area and yet the
area through which blood can flow in the large artery
obviously is greater than the area through which blood
Patients and Methods
Ninety-eight necropsy patients were included in this
study. Twenty patients had clinically isolated angina
pectoris4 (table 1). Each died within 3 days of an aortocoronary bypass procedure, and during life their
only evidence of myocardial ischemia was angina pectoris; none had had clinical evidence (historical and
electrocardiographic) of acute myocardial infarction
or chronic congestive heart failure. Twenty-three
patients had fatal transmural (involving greater than
the inner half of the left ventricularwall) acute
myocardial infarcts' which by history and by
histologic examination were 24 hours to 30 days old.
Nineteen patients died suddenly and unexpectedly,
and this subgroup hereafter will be referred to as
sudden coronary death.3 Each died within 6 hours
after the onset of chest pain, which, if present, began
outside the hospital. None ever had evidence of con-
From the Pathology Branch, National Heart, Lung, and Blood
Institute, National Institutes of Health, Bethesda, Maryland.
Address for correspondence: William C. Roberts, M.D., Building
IOA, Room 3E-30, National Institutes of Health, Bethesda,
Maryland 20205.
Received November 5, 1979; revision accepted March 31, 1980.
Circulation 62, No. 5, 1980.
gestive heart failure. At necropsy, at least one of the
three major epicardial coronary arteries was greater
than 75% narrowed in cross-sectional area by atherosclerotic plaques. None of these 19 patients at necropsy had ventricular wall myocardial coagulation
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CIRCULATION
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VOL 62, No 5, NOVEMBER 1980
Internal diameter
Internal diameter
2
cm
_
75
_. ..v
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>75%
X-sectional narrowing
Residual lumen (cm2)
\
>75%
X-sectional
3
narrowing
rv.7 5
FIGURE 1. Diagram of transverse sections of two coronary arteries, both of which are narrowed greater
than 75% in cross-sectional area. Although both are similarly narrowed in cross-sectional area, one can accommodate a much larger blood flow because it is much larger.
necrosis. At necropsy, 36 patients had healed
transmural myocardial infarcts. These 36 patients
were divided into two groups: 18 with nonfatal healed
myocardial infarcts,7 i.e., patients who had had acute
myocardial infarcts that healed and who subsequently
died of noncardiac conditions, and 18 with fatal healed
myocardial infarcts,6 i.e., patients who had had
transmural acute myocardial infarcts that healed and
either immediately or later developed chronic congestive cardiac failure that became intractable and
TABLE 1. Mean Cross-sectional Area of the Right, Left Anterior Descending, and Left Circumflex Coronary
Arteries, Heart Weight, Age and Sex in the Five Groups of Coronary Patients and in the Two Groups of Control
Subjects
Mean XSA
Heart weight
(mm2)
of R,
Sex
Age (years),
(g),
LAD, LCCA,
F
Pts
Group
M
range and mean range and mean range and mean
Coronary patients
1-Angina pectoris
12
8
20
37-59
240-520
2.7-13.1
(49)
(386)
(6.0)
2 Healed MI
(noncardiac death)
18
15
3
25-80
3-Acute MI
23
17
6
33-82
310-540
(430)
310-720
3.3-12.3
(6.9)
3.6-11.9
(58)
(482)
(7.6)
4-Sudden coronary death
19
17
2
28-85
300-670
5-Healed MI
(cardiac death)
18
18
0
(54)
31-78
(58)
(459)
450-800
(588)
5.2-14.9
(7.7)
5.3-13.4
(8.6)
(63)
Control subjects
26-74
135-470
2.04-9.07
(51)
(309)
(5.0)
2 Aortic valve
15
13
2
34-81
550-1050
7.1-14.9
(56)
(730)
(9.6)
Abbreviations: XSA = cross-sectional area; R = right coronary artery; LAD = left anterior descending
coronary artery; LCCA = left circumflex coronary artery; MI = myocardial infaretion.
1 Cancer
31
17
14
CORONARY ARTERIAL SIZE/Roberts and Roberts
955
FIGURE 2. Drawing of projection microscope (left) and video planimetry (VP) console (right) used to quantify the degree of
coronary arterial cross-sectional area
narrowing. The histologic section of coronary artery, mounted on a glass slide, is
placed on the stage of the projection
microscope; the magnified (X 650) image is
traced onto opaque paper (lower left). The
tracing is then placed under the focused
camera of the VP console. The reflected
light is adjusted so that the camera sees
either the original lumen (or as done in some
other studies2 7) the area of the atherosclerotic plaque (lower right).
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fatal. Patients with associated valvular, congenital or
pericardial heart diseases or hypertrophic cardiomyopathy or myocardial diseases not secondary to
coronary disease were excluded from these coronary
subgroups.
The hearts in all 98 patients were studied in similar
fashion. The hearts were cleaned of postmortem clots,
all portions of parietal pericardium were excised, the
aorta and pulmonary trunk were excised about 2 cm
cephalad to their sinotubular junctions and the hearts
were carefully weighed. After fixation in 10% buffered
formalin for at least 24 hours, the major epicardial
coronary arteries were excised intact from the hearts
and fixed again for at least another 24 hours. They
were then x-rayed and if calcific deposits were present
the arteries that contained calcium were decalcified.
The right, left main, left anterior descending, and left
circumflex coronary arteries were then cut into 5-mmlong segments at right angles to the longitudinal axes
of the arteries and each segment was numbered
chronologically beginning at its origin from the aorta
(right and left main coronary arteries), or in the case
of the left anterior descending and left circumflex
arteries, from their origin from the left main. Each 5mm segment was processed and dehydrated in
alcohols and xylenes, embedded in paraffin, cut, and
stained by Movat's pentachrome method. The latter
was used because it clearly delineates the artery's internal elastic membrane.
We studied three histologic sections of coronary
artery from each patient, for a total of 294 sections.
From each patient, one Movat-stained section of the
right, left anterior descending and left circumflex coronary arteries was examined. Each section was
prepared from the first 5-mm long segment - the
artery's most proximal portion - of the respective
artery.
The cross-sectional areas of the coronary arteries
were determined by planimetry (KE-compensating
polar planimeter) (fig. 2). Each histologic section was
positioned on the stage of a projection-light
microscope that magnified the image 650 times (fig.
2). The circumference of the internal elastic membrane was then traced on white paper. Although all
sections examined had atherosclerotic plaques in the
lumens, this study concerned the total area enclosed
by the artery's internal elastic membrane irrespective
of the presence or absence of superimposed
atherosclerotic plaque. Where the internal elastic
membrane was artifactually indented, the lumen was
extrapolated to a circular form. Each tracing then was
placed under a focused camera and the resultant video
signal was passed through an electronic integrator and
displayed on a television monitor (fig. 2).8 The
threshold level of the television monitor was adjusted
so that the area of opacification estimated by video
planimeters activated by the video signal corresponded to the original lumen (area enclosed by the
internal elastic membrane). The analog output
voltages of the video planimeters, calibrated on a grid
system, provided on-line measurements of the crosssectional area.
The area of each artery enclosed by the internal
elastic membrane provided by videoplanimetry was
converted into actual area in the following manner. A
slide containing a 2-mm scale was projected onto tracing paper and recorded via the projection microscope
in the same manner in which histologic sections of coronary arteries were projected and traced. The traced
scale was converted into a square box, which was
placed under the focused camera of the video
planimeter console. The scale of the video-planimeter
was then set to read 4 mm2 because the original length
of one side of the box had been projected and traced
from a 2-mm long scale. The actual cross-sectional
areas of the right, left anterior descending and left circumflex coronary arteries were added together to obtain the sum of the cross-sectional area of each
956
ClIRCULATION
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patient. This number was divided by 3 to obtain the
mean cross-sectional area for each patient.
For comparison with the 98 coronary patients, 46
subjects served as controls. During life none of them
had clinical evidence of coronary heart disease and at
necropsy none had any of their major coronary
arteries narrowed greater than 75% in cross-sectional
area by atherosclerotic plaques. The control subjects
consisted of two major groups: 31 patients died of
various cancers and 15 died of complications of aortic
valve disease. Of the 31 control subjects with cancer,
26 had hearts that weighed 400 g or less and the other
five had hearts that weighed 410-470 g. Of the 15
patients with aortic valve disease, 11 had stenosis with
peak systolic pressure gradients between left ventricle
and a systemic artery of 12-155 mm Hg (average 74
mm Hg), and the remaining four patients had pure
aortic regurgitation of severe degree. The reason for
selecting these two groups of control subjects was to
obtain both normal and near-normal-sized hearts and
also very large hearts. The coronary arteries in the 46
control subjects were examined in the same manner as
in the 98 study patients.
Results
The findings in this study are summarized in tables
1-4. Except for similar values in the acute myocardial
infarct and sudden coronary death subgroups, the
mean values of the mean cross-sectional areas of each
of the three major coronary arteries in each of the subgroups of coronary patients differed significantly
(p < 0.0001), and also, these values differed sig-
VOL 62, No 5, NOVEMBER 1980
nificantly (p < 0.0001) from those of the control
subjects. The 20 patients with angina pectoris had the
smallest coronary arteries (mean cross-sectional area
of each of the 60 arteries 6.0 mm2) and the 18 patients
with healed myocardial infarcts with progressive and
eventually fatal congestive heart failure had the
"largest" coronary arteries (mean cross-sectional area
of each of the 54 arteries 8.6 mm2). The 23 patients
with acute myocardial infarcts and the 19 with sudden
cardiac death had similar-sized coronary arteries
(mean cross-sectional area of each of the 126 arteries
7.6 mm2) and the 18 patients with healed myocardial
infarcts and subsequently asymptomatic courses and
noncardiac causes of death had relatively small coronary arteries (mean cross-sectional area of each of
the 54 arteries 6.9 mm2). The 31 control subjects with
cancer had the smallest coronary arteries of any group
(mean cross-sectional area of each of the 93 arteries
5.0 mm2) and the 15 patients with aortic valve disease
had the largest coronary arteries (mean area of each of
the 45 arteries 9.6 mm2) (p < 0.0001).
The differences in cross-sectional area of the coronary arteries among the subsets of 98 coronary
patients and between and among the 46 control subjects is attributable primarily to differences in heart
weight (tables 1-3). The coronary subgroup with
angina pectoris had the smallest hearts (average 386
g); the subgroups, with healed myocardial infarction
with chronic congestive cardiac failure, had the largest
hearts (average 588 g). The other three groups were intermediate. The cancer control subjects, who had the
smallest coronary arteries, had the smallest hearts
TABLE 2. Relation of .M1ean Cross-sectional Area of the Right, Left Anterior Descending and Left Circumflex Coronary A rteries to
the Heart Weight in the 98 Coronary Patients and in the 46 Control Subjects
Heart weight (gs)
301-400
401-500
501-600
Parameter
601-700
< 300
> 700
Totals
Coronary patients
1 No. patients
2-Age (years),
range and mean
3-Male:female ratio
4 Heart weight (g),
range and mean
5-Mean XSA (mm2) of R,
LAD and LCCA
2
36
25-82
26
36-8.5
22
7
49-78
98
25-85
(56)
79:19
240-800
(468)
(61)
48-78
(61)
24:2
420-500
31-77
(59)
21:1
510-600
6:1
610-670
5:0
720-800
(465)
(;546)
(635)
(754)
5.7-12.8
(10.3)
2.7-14.9
8
45-81
(54)
7:1
46
26-81
(53)
30:16
43-54
(49)
0:2
240-300
(270)
(532)
(58)
23:13
310-400
(360)
3.2-5.6
2.7-10.6
4.4-14.9
5.6-13.3
6.2-13.4
range and mean
(4.4)
(5.9)
(7.2)
Control subjects
(8.9)
(9.7)
1-No. subjects
2-Age (years),
range and mean
3-Male:female ratio
16
26 67
(47)
7:9
10
27-67
4
3
54-66
(61)
34-69
(56)
3:0
(52)
6:4
5
O
56-74
(64)
4:1
3:1
4-Heart weight (g),
135-300
310-400
410-470
550-600
range and mean
(243)
(352)
(436)
(568)
5-Mean XSA (mm2) of R,
LAD and LCCA,
2.0-6.3
.3.0-9.1
5.8-9.0
7.1-10.4
(5.9)
range and mean
(3.8)
(7.0)
(8.4)
=
P
=
Abbreviations: XSA
cross-sectional area:
right coroniary artery; LAD
LCCA = left circumflex coronary arterv.
(7.4)
620-700
(660)
720-1050
(838)
135-1050
(447)
7.7-8.8
8.2-14.9
2.0-14.9
(8.2)
(10.8)
(6.5)
left anterior descending coronary artery;
CORONARY ARTERIAL SIZE/Roberts and Roberts
957
TABLE 3. Relation of Mean Cross-sectional Area of the Right, Left Anterior Descending and Left Circumflex
Coronary Arteries to Sex with Actual and Equalized Heart Weights in the 98 Coronary Patients and in the 46
Control Subjects
Mean XSA (mm2)
Mean XSA (mm2)
of R, LAD, and
Heart weight
for R, LAD and
Equalized mean
(g),
No.
LCCA,
LCCA
heart weight
range and mean
patients range and mean
Coronary patients
7.1
450
2.7-14.9
79
Men
310-800
Women
Men
19
30
(490)
(7.7)
240-610
(376)
3.2-11.4
200-1050
(5.9)
Control subjects
2.0-14.9
(509)
450
7.1
450
6.8
(7.7)
6.0
450
2.0-8.6
135-750
(4.4)
(329)
Abbreviations: XSA = cross-sectional area; R = right coronary artery; LAD = left anterior descending
coronary artery; LCCA = left circumflex coronary artery.
Women
16
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(average 309 g) and the aortic valve control subjects,
who had the largest coronary arteries, had the largest
hearts (average 730 g). When the heart weights for
each of the seven groups (five subgroups of coronary
patients and two control groups) were equalized by
using the same regression coefficient, no significant
differences (p = 0.63) were found among the mean
values of cross-sectional area of the coronary arteries
(table 3).
The mean values of cross-sectional areas of the coronary arteries in the women were significantly
(p < 0.0001) different from the values in the men
(mean cross-sectional area of each of the 19 women's
57 coronary arteries was 5.9 mm2 [range 3.2-11.4
mm2] and of the 79 men's 237 arteries, 7.7 mm2
[2.7-14.9 mm2]) (table 3). These mean differences,
however, resulted from differences in heart weight.
The heart weights of the 19 women ranged from
240-610 g (mean 376 g) and those of the 79 men,
310-800 g (mean 490 g). When the heart weights for
the women and men with coronary heart disease were
equalized by using the same regression equation, no
significance differences in mean areas of the-coronary
arteries between the sexes was apparent (table 3).
Similar findings regarding sex were observed in the
control subjects (16 women and 30 men). Of the 31
cancer control subjects, 14 were women (mean coronary cross-sectional area 3.9 mm2 and mean heart
weight 280 g) and 17 were men (mean coronary crosssectional area 6.0 mm2 and mean heart weight 334 g);
of the 15 aortic valve disease control subjects, two
were women (mean coronary cross-sectional area 7.9
mm2 and mean heart weight 675 g) and 13 were men
(mean coronary cross-sectional area 9.9 mm2 and
mean heart weight 738 g).
Age had a small independent effect on the mean
cross-sectional area of the coronary arteries in the
study patients. The younger patients had smaller coronary arteries than the older patients. The mean crosssectional area of the 33 coronary arteries in the 11
patients ages 40 years or younger was 5.7 mm2; in the
150 arteries in the 50 patients ages 41-60 years, the
mean area was 6.8 mm2, and in the 111 arteries of the
37 patients over 60 years of age, the mean area was 8.5
mm2 (p < 0.0001) (table 4). Most of the difference in
cross-sectional area among the age groups resulted
from differences in heart weights. The younger
patients had smaller hearts, on the average, than the
older patients. The mean heart weight in the 11
patients ages 40 years and younger was 395 g; in the 50
patients ages 41-60 years, 456 g, and in the 37 patients
older than 60 years, 506 g (p < 0.0001). When heart
weight was equalized among the 98 coronary patients
after dividing them into five age groups (< 40, 41-50,
51-60, 61-70 and > 70 years), the mean crosssectional areas were significantly (p > 0.001) different
except in the age groups 41-60 years (table 4). Thus,
aging itself among the coronary patients increased the
cross-sectional areas of the three major coronary
arteries. The nature of selecting the control subjects,
i.e., those with normal- or near-normal-sized hearts
(cancer victims) and those with huge hearts (aortic
valve disease victims), prevented adequate numbers of
patients in each of the five age-group divisions to
determine if age per se caused the coronary arteries of
the control subjects to enlarge.
Discussion
Our findings indicate that there are significant
differences in the mean cross-sectional areas of the
three major coronary arteries in patients with various
coronary events, but that these differences are nearly
all accounted for by differences in heart weight and, to
a slight extent, age. Thus, the size of the coronary
artery (the area enclosed by the internal elastic membrane, irrespective of the degree of luminal narrowing
by atherosclerotic plaque) is unimportant in determining whether a person develops evidence of myocardial ischemia. Although the area through which blood
958
VOL 62, No 5, NOVEMBER 1980
CIRCULATION
TABLE 4. Relation of Mean Cross-sectional Area of the Right, Left Anterior Descending and Left Circutnflex Coronary Arteries to
Age in the 98 Coronary Patients and in the 46 Control Subjects
Age (years)
Parameter
< 40
41-50
51-60
61-70
> 70
Totals
Coronary patients
1 No. patients
2 Age (years),
range and mean
3 Heart weight (g)
range and mean
4-Mean XSA of R,
LAD and LCCA,
range and mean
11
25-40
25
41-50
(35)
300-720
(392)
(47)
240-750
(480)
2.7-10.6
(3.7)
340-320
25
23
61-70
14
72-85
(78)
330-770
(433)
(65)
310-800
(503)
(510)
98
25-85
(56)
240-800
(468)
3.2-13.1
4.2-13.3
3.3-13.4
(7.1)
(6.6)
(8.1)
5.0-14.9
(9.2)
2.7-14.9
(7.4)
51-60
(55)
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Control subjects
7
13
10
14
2
1-No. patients
46
42-1
50
51-60
22-39
61-69
74-81
2 Age (years),
26-81
range and mean
(32)
(46)
(.56)
(65)
(78)
(53)
135-700
230-810
3-Heart weight (g),
2,50-1050
210-660
410-770
135-1050
range and mean
(306)
(405)
(633)
(401)
(t590)
(447)
4-Mean XSA of R,
5.0-14.6
2.1-14.9
LAD and LCCA,
2.0-8.8
3.5-10.5
9.0-9.3
2.0-14.9
range and mean
(4.5)
(.5.8)
(8.3)
(6.6)
(9.2)
(6.5)
cross-sectional area; R = right corolnary artery; LAI) = left anterior descending coronary artery;
Abbreviations: XSA
LCCA = left circumflex coronary artery.
might flow in a large artery narrowed greater than
75% in cross-sectional area by atherosclerotic plaque
is greater than that of a small artery with a similar
degree of cross-sectional area narrowing, the larger
artery is large because the myocardial mass that it
must perfuse is large and vice versa. Consequently, a
75% cross-sectional area narrowing in a large coronary artery has the same effect on myocardial perfusion as a similar degree of narrowing in a small coronary artery. The patients with angina pectoris had
the smallest coronary arteries because they had the
smallest hearts. The patients with healed myocardial
infarcts who are left with chronic congestive heart
failure that becomes intractable and fatal had the
largest coronary arteries because they had the largest
hearts. However, patients with healed myocardial infarcts who recovered completely, never had further
evidence of myocardial ischemia, and died from noncardiac causes tended to have relatively small hearts
(just larger, on the average, than those of the pure
angina pectoris group) and, therefore, relatively small
coronary arteries. The patients with sudden coronary
death and those with acute myocardial infarcts had
similar-sized hearts, and, therefore, similar-sized coronary arteries. Previous findings revealed similar
degrees of cross-sectional narrowing throughout the
entire lengths of the coronary arteries in patients with
sudden coronary death and acute myocardial infarction.3 In both groups, 35% of the four major coronary arteries were narrowed greater than 75% in
cross-sectional area. Also of note is the previous
observation4 that the angina patients had the most
severe degrees of cross-sectional area narrowing (48%
of their four major coronary arteries were narrowed
more than 75% in cross-sectional area) and the
patients with healed myocardial infarcts irrespective
of whether or not they died from cardiac or noncardiac causes had the least degree of severe crosssectional area narrowing (30% of their major coronary
arteries were greater than 75% narrowed in crosssectional area by atherosclerotic plaque).', 7
This study also demonstrated that sex did not have
an independent effect on the size of the coronary
arteries. Women, on the average, however, had
smaller coronary arteries than men, but this difference
is entirely accountable for by differences in heart
weight. This sex difference in heart size might explain
why the early mortality after aortocoronary bypass
operations, as reported by Hall and associates,9 is
higher in women than in men. Women have smaller
hearts, on the average, than men, and most of the
bypass operations are performed for angina, which in
itself is associated on the average with the smallest
hearts of any of the various coronary events. The combination of pure angina and womanhood, in general,
makes for relatively small hearts and, therefore,
relatively small coronary arteries. The smaller the coronary artery, the greater the difficulty in inserting a
conduit and the greater the likelihood after the coronary anastomosis that the runoff via the conduit into
the native coronary artery will not be good. When coronary bypass fails to result in an adequate increase in
myocardial oxygenation, the greater the likelihood of
early death. 101
Age affected the cross-sectional area of the coronary arteries. This observation may suggest that it
takes less cross-sectional area narrowing in younger
persons to produce myocardial ischemia than it does
CORONARY ARTERIAL SIZE/Roberts and Roberts
in older persons, heart weight and other factors being
equal. Elderly persons are known to have larger and
more tortuous coronary arteries than younger adults.
This "senile dilatation" comes about through both
transverse widening and longitudinal lengthening. The
present study indicates that this so-called senile dilatation, which occurs as a more-or-less normal event in
insignificantly narrowed coronary arteries, also occurs, but probably to a lesser extent, in coronary
arteries that are significantly narrowed by atherosclerotic plaques. Because arteries tend to be larger in
older adults than in younger adults, coronary bypass
anastomoses may be more readily accomplished in the
old than in the young. From a technical standpoint,
the young woman with pure angina pectoris may be at
a greater risk of early mortality or lesser improvement
than the elderly woman with similar symptoms and a
similar-sized heart.
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Acknowledgment
We thank Margaret C. Wu, Ph.D., Biometrics Branch, National
Heart, Lung, and Blood Institute, National Institutes of Health, for
providing the statistical analyses of the data presented.
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Circulation. 1980;62:953-959
doi: 10.1161/01.CIR.62.5.953
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