PETERS, DONOVAN, KAWAI, KWAN-GETT, ZWART AND KOLFF 
413 
600 
1 
PUL. FUNCT. 
ML 
FUNCT. RES. CAP. (xlO) 
240 HRS. »• 
PUMPINO 
Figure 15. — Tidal volume, O2 consumption and functional residual volume in a calf with an artificial heart. 
creased with the time of pumping. This is cur- 
rently one of the major problem areas to be 
solved in artificial heart research, namely, to 
reduce the venous inflow pressure and still 
maintain an adequate cardiac output. Respira- 
tory function was variable as some calves re- 
quired nasal O2 or respirator support while the 
long-surviving calf (Figure 14 and 15) re- 
quired no respiratory support for eight days, 
but did exhibit a gradually decreasing func- 
tional residual volume (from 4 liters to below 
2 liters) . Varying degrees of atelectasis were 
found in all calves at autopsy. All calves pro- 
duced urine either spontaneously or by stimula- 
tion with diuretics. In calves with high hemoly- 
sis (i.e., artificial hearts with rough dacron 
surfaces), plasma hemoglobin usually ranged 
above 30 mg% and there was hemoglobinuria. 
Terminally, this was manifested by an increas- 
ing BUN (Figure 16) and red cell casts, 
tubular necrosis and infarction, and areas of 
congestion in the kidney upon microscopic exam- 
ination. In calves with smooth artificial heart 
surfaces, hemolysis was low, usually below 10 
mg% however, there was greater evidence of 
embolization in the kidneys, brain and lungs, 
suggesting that the fibril surface, although it 
caused greater hemolysis, provided a reticulum 
dacron structure for a pseudo-intima to form. 
Two calves were terminated because of obvious 
sepsis. In one calf, (260 hour survival) the 
intima of the artificial heart was lined with a 
green (Pseudomonas cultured) membrane. 
Other pathological findings at autopsy in- 
cluded congestion and/or central lobular 
necrosis of the liver and an average 1.2 liters 
of ascites most likely from the acute high cen- 
tral venous pressure. 
In spite of these drastic physiological 
changes, the calves were usually responsive to 
