F. T. GALYSH AND R. F. WALLIN 
1043 
Hearts, extirpated for a period of time and kept 
in a frozen state followed by thawing and dis- 
tention with saline, are about the same size as 
hearts fibrillated in situ, but exhibit some short- 
ening of the ventricles. The distended heart of a 
large 104 kg. pig was much smaller than dis- 
tended sheep or calf hearts and was globular in 
shape. This was particularly evident from the 
prepared casts of these hearts (Figure 10) . 
Studies of direct mechanical ventricular as- 
sist devices in the rapidly growing calf are com- 
plicated by the fixed sizes of such devices and 
the variable size of the heart. Some means of 
pre-surgically predicting the size of the heart in 
this species would be desirable. Since organ 
sizes generally are related to body weight, heart 
weight to body weight correlations were done in 
68 calves fasted for 18 to 36 hours. Hearts were 
removed, drained of blood, and weighed. The 
cardiac weights were plotted versus body 
weights and a least squares regression line was 
computed (Figure 11). The correlation coeffi- 
cient was found to be 0.755 indicating that only 
a rough correlation exists between heart weight 
and body weight. The relatively poor correla- 
tion was in part related to variability in the vol- 
ume of ingesta found in the rumens of these 
calves at necropsy. 
Of particular interest in the design of direct 
mechanical ventricular assist devices (cups, 
squeezers) is the fact that the length of the pos- 
terior aspect of the ventricles in both sheep and 
calves is much shorter than the length of the 
anterior aspect. Thus, it may be necessary to 
design asymmetrical cups unlike those cur- 
rently being evaluated. Additionally, in dis- 
tended hearts there is a prominent bulging of 
the right ventricular outflow tract, which may 
be traumatized if a symmetrical cup is applied. 
DIMENSIONS OF GREAT VESSELS 
We sought to compare the dimensions of the 
aorta in calves and in man since these data have 
some relevance to the design of intra-aortic bal- 
loons and to connectors used with artificial 
hearts. 
With the cooperation of the Department of 
Radiology at Wesley Memorial Hospital in Chi- 
cago, Illinois, thoracic aortograms from 14 clin- 
FiGURE 10. — Differences in shape and size of hearts from sheep (left), pig (center), and calf (right). 
