1044 
ANIMAL RESOURCES 
1000- 
900 - 
oUU 
— r 
E 
700 - 
O 
— 
Ann - 
OUU 
JZ 
0> 
500- 
400- 
o 
V 
X 
300- 
200- 
100- 
0 - 
CALVES 
y = 1 66.44 + 1.929X 
r = 0.755 
25 
Body Weight (kg.) 
50 75 100 125 150 
0 40 80 120 160 200240280 320 
Body Weight (lbs.) 
Figure 11. — Correlation between heart weight and body 
weight in calves. 
that aortic i.d. would be reduced in cardiogenic 
shock states, particularly in those patients with 
intact elastica. 
We measured the aortas of 11 anesthetized 
calves and found that the calf's thoracic aorta 
tapers significantly ; the i.d. at the level of the 
ligamentum arteriosum varied from 18 to 25 
mm and at the level of the diaphragm from 14 
to 16mm. These values tended to be smaller in 
calves whose blood pressure was reduced below 
80 mm Hg by exsanguination. There was poor 
correlation between aortic diameter and blood 
pressure or body weight from 50 to 160 kg. 
The diameter of the root of the aorta and PA 
was estimated by actual obturator measurement 
in situ in calves on cardiopulmonary bypass. 
Similar measurements were made of the cavae 
(junctional area) and LA (below the annulus). 
Structure 
Aortic root 
Pulmonary artery root 
Cavae 
Left Atrium 
(above pulmonary veins) 
Diameter, mm 
28-32 
27-31 
18-21 
42-48 
ical patients were examined. The patients' hos- 
pital records permitted characterization of sex, 
height, weight and history. The internal diame- 
ter (i.d.) of the thoracic aortas were estimated 
by direct measurement from aortograms. 
Table II summarizes data from the aorto- 
grams of the clinical patients. It was possible to 
obtain the diameter of the thoracic aorta at the 
level of the diaphragm in only two patients. All 
measurements in the table are i.d. corrected for 
film magnification. A normal 1.5 mm wall thick- 
ness may be used to calculate outer diameters. 
Note that in Patient 6 not much taper of the 
aorta was apparent from the seventh rib level 
to the diaphragm. Mean i.d. 1 cm below the aor- 
tic arch in females was estimated to be 23.9 mm 
and in males 28.3 mm. Several factors which 
may have biased dimensions of these aortas as 
contrasted to "normal" aortas include long- 
standing hypertension in a number of these pa- 
tients and the effect of the high pressure con- 
trast dye injections at the root of the aorta. In 
considering design criteria for intra-aortic bal- 
loons consideration should be given to the fact 
SUMMARY 
To aid in the design of cardiovascular de- 
vices, several dimensional measurements of the 
cardiac ventricles and great vessels were made. 
These revealed that the ventricles of calves and 
adult sheep are similar in size and taper signifi- 
cantly to an apex, whereas the ventricles of 
adult pigs are smaller and more rounded in 
shape. The internal diameters of descending 
thoracic aortas just below the arch averaged 
23.9 mm in human females, 28.3 mm in human 
males, and ranged from 18 to 25 mm in calves. 
The internal diameters of the great vessels 
measured in situ in 100 to 120 kg calves were as 
follows : aortic root, 28-32 mm ; pulmonary ar- 
tery root, 27-31 mm; cavae (at junctional re- 
gion), 18—21 mm; left atrium (just above pul- 
monary veins) , 42-48 mm. 
ACKNOWLEDGMENTS 
The authors wish to acknowledge the efforts 
of Chung- Yuan Lin, M.D., in making the meas- 
urements of the cardiac and aortic dimensions 
