400 
SURGERY AND TRANSPLANTATION 
calves calm. These calves were immunized 
against calf diseases (Salmonella, Enterotox- 
emia, Clostridium Perfringens (types C & 
D), Parainfluenza (type 3), Infectious Bovine 
Rhinotracheitis, Clostridium Chauvoei), and 
had a medical record chart and a food intake 
chart. When the calves were weaned at approxi- 
mately two months of age, they were trans- 
ferred to growing pens and placed on a free 
choice diet of grain, alfalfa pellets and water 
(constantly running). The growing pens were 
half straw bed and half cement with flushing 
troughs for daily removal of waste. The calves 
in the growing pen gained 1 to 2 pounds in total 
body weight per day and were kept in quaran- 
tine as no other animal traffic was allowed at 
the facility. They were regularly evaluated by 
a veterinarian. 
For artificial heart research calves, it is 
necessary to have base line blood chemistry 
which was performed on our calves usually 
twice prior to implantation. The routine con- 
trol blood chemistry data included calcium, 
sodium, potassium, inorganic phosphate, blood 
sugar, blood urea nitrogen, uric acid, cholesterol, 
total protein, albumin, total bilirubin, alkaline 
phosphatase, lactic dehydrogenase, serum glu- 
tamic oxaloacetic transaminase and fibrinogen. 
Hematology evaluation consisted of a complete 
blood count, platelet count and hematocrit. Other 
determinations performed on occasion were 
plasma hemoglobin, norepinephrine, epine- 
phrine and 17-OH steroids (compounds F & B) 
and when the calves were delivered to our divi- 
sion, lung function studies were performed 
(tidal volume, O2 consumption, respiratory rate, 
minute ventilation and functional residual 
capacity) . 
The results of this project provided a re- 
search calf that was raised under controlled con- 
ditions, diet, immunizations, temperature and 
humidity, and was delivered to our facility with 
a medical record card and base line blood chem- 
istry data. The use of these calves provided 
disease-free calves of the same breed, approxi- 
mately the same age and weight, for implanta- 
tion of the artificial heart and evaluation of its 
effects. 
EXPERIMENTAL PROCEDURES 
One week prior to an artificial heart experi- 
ment, the principal investigators have experi- 
mental planning sessions to define: 1) the pur- 
pose or purposes of the experiment; )2 what 
experimental procedures will be performed; 
and 3) individual responsibilities. A prelimi- 
nary protocol is written and distributed to all 
members of the research team for their sug- 
gestions and criticisms. (This sometimes re- 
quires another discussion session before the 
final protocol is written.) Usually, the day be- 
fore the experiment, all members of the re- 
search team meet and go over the experimental 
protocol. At this time, the postoperative inten- 
sive care calf sitters are scheduled for a period 
of one week in advance. 
Heart Testing 
The Kwan-Gett hemispherical artificial 
heart ^ was used in most of our total heart re- 
placement experiments during the past year. 
Each ventricle has a rigid circular base at- 
tached to a hemispherical diaphragm made of 
0.030 inch dacon-reinforced silicone rubber. A 
0.060 inch dacron-reinforced silicone rubber 
housing with inflow and outflow connectors fits 
over the diaphragm-housing junction. Outflow 
and inflow valves used include silicone rubber 
flap valves, tricuspid outflow valves and Wada- 
Cutter valves. 
Figure 1 illustrates one cardiac cycle of one 
ventricle in which filling pressure regulates 
inflow rate to the heart and displacement of 
the diaphragm during diastole (70% of the 
cycle) . The heart responds to Starling's Law 
with an increase in filling pressure causing an 
increase in cardiac output. During systole, air 
pressure from an external source displaces the 
diaphragm and blood is ejected through the 
aortic valve (30% of one cycle). Both right 
and left ventricles are operated simultaneously 
at a fixed rate of 120 b/min and at 4 psi and 
6 psi driving pressure respectively. Surfaces 
used as the intima of the artificial heart have 
included smooth silicone rubber and silicone 
rubber lined with dacon fibrils. 
Before an artificial heart is implanted, it is 
subjected to two types of tests in vitro. One 
