1042 
ANIMAL RESOURCES 
mensions of the hearts of three species, these 
measurements were made in nine calves, two 
sheep and one pig. 
The animals were anesthetized with halo- 
thane and the following cardiac dimensions re- 
corded (Table I) : 
1. Circumference at the base as well as at the 
largest circumference — by carefully pass- 
ing a suture around the ventricles and 
measuring its length. 
2. Several diameters with the aid of calipers 
as follows : 
a. Dorso-Ventral (DV) diameter — from 
origin of the pulmonary artery on the 
anterior aspect to the posterior aspect 
at the base of the heart. 
b. Lateral diameter at base of the ventri- 
cles. 
c. Similar DV diameter at the largest di- 
ameter of the ventricles. 
d. Lateral diameter taken at the largest 
diameter of the ventricles. 
e. Oblique diameter I — at right angles to 
the interventricular septum and at a 
45° inclination to both the DV and lat- 
eral diameter. This is the larger of the 
two oblique diameters measured. 
f. Oblique diameter II — parallel to the in- 
Table I. — Dimensions of Cardiac Ventricles of Sheep 
and Calves in mm. 
Measurement* 
Calf 
31 
-0 
Calf 32 
-0 
Sheep 
1-0 
Sheep 2-0 
Body wt., kg 
65.9 
67.7 
73.9 
91.4 
Systolic blood press. 
105 
75 
115 
160 
Diastolic blood press. 
80 
45 
98 
105 
Mean blood press. 
88 
60 
107 
125 
NSR** 
VP*** 
NSR 
VF 
NSR VF 
NSR 
VF 
Base circumference 
290 
335 
270 
310 
280 
305 
265 
357 
Largest circumference 
370 
335 
390 
317 
368 
320 
382 
Base-DV diameter 
90 
105 
103 
95 
90 
90 
105 
111 
Base-Lat. diameter 
90 
100 
103 
117 
92 
100 
105 
111 
Largest diameter-DV 
108 
105 
115 
115 
100 
114 
120 
129 
Largest diameter-Lat. 
120 
110 
115 
125 
100 
114 
120 
129 
Oblique diameter I 
130 
140 
127 
Oblique diameter II 
95 
105 
100 
Length — PA to apex 
120 
140 
120 
140 
115 
130 
120 
140 
Length — LA to apex 
110 
135 
105 
110 
105 
110 
115 
125 
Length — RA to apex 
120 
135 
115 
140 
110 
125 
122 
130 
Length — post, sulcus 
95 
105 
85 
100 
90 
100 
100 
112 
to apex 
Ring — 100 mm 
12 
18 
15 
12 
17 
12 
12 
16 
Ring — 150 mm 
25 
35 
30 
28 
25 
25 
25 
23 
Ring — 200 mm 
40 
45 
52 
43 
50 
45 
52 
35-38 
* Terms defined in text 
** NSR = Normal sinus rhythm 
*•* VF = After one minute of ventricular fibrillation 
terventricular septum and at a 45° in- 
clination to both the DV and lateral di- 
ameters. This is the smaller of the two 
oblique diameters measured. 
3. Four ventricular lengths were measured, 
again with the aid of calipers as follows: 
a. Pulmonary artery (PA) to apex. 
b. Coronary sulcus at left atrium (LA) to 
apex. 
c. Coronary sulcus at right atrium (RA) 
to apex. 
d. Posterior sulcus to apex. 
4. Taper at the ventricular apex was esti- 
mated using three rings fashioned of duc- 
tile wire. These rings were 10, 15, and 20 
cm in circumference. The rings were 
slipped around the apex and snugged up 
around the ventricles. The average dis- 
tance from these rings to the apex was re- 
corded. 
The heart was then fibrillated electrically 
(6.3 volts rms, 60 Hz, applied for 2 to 3 sec- 
onds) and allowed to fibrillate for one minute at 
which time the dimensions already discussed 
above were estimated. During this procedure 
mechanical ventilation of the lung was contin- 
ued. The data are depicted in Table I. 
Following these measurements the major car- 
diac vessels (vena cavae, pulmonary arteries, 
aorta and pulmonary veins) were ligated and 
the heart extirpated. The heart was then dis- 
tended by filling the cardiac chambers with 
RTV silicone rubber or plaster or saline solution 
to the approximate size measured previously 
when the hearts were either in normal sinus 
rhythm or distended in fibrillation. RTV silicone 
rubber molds were then cast around these 
hearts. Positive casts were then made either of 
plaster of Paris or of Vel-Mix Stone. ^ Shrink- 
age is minimal with these materials. 
Appreciable distention of the fibrillating ven- 
tricles is apparent when one compares circum- 
ferences and lengths of the ventricles in sheep 
and calves (Table I). Calves and sheep hearts 
fibrillating in situ are of about the same size. 
There was poor correlation between ventricular 
dimensions and body weight (66-91 kg.). 
s Kerr Manufacturing Co., Division of Sybron Corp., Romulus, 
Michigan 48174 
