C. GRANT LA FARGE AND W. F. BERNHARD 
83 
Figure 3. — A lateral frame from a biplane angiogram recorded at 6 frames per second in a 
control calf following coronary infusion of carbon dioxide. Arrows point to areas of 
accumulation of CO:, including the branches of the circumflex coronary artery. 
bypass began 38 days previously with micro- 
sphere infarction and the elevation of the 
LVedp to 45 mmHg. By the time of this second 
study, the LVedp v^^as 29 mmHg (q.v.. Figure 
10). At the final study, after 64 days of total 
bypass (72 days of pumping), the LVedp was 
22 mmHg. The animal died after stepping on 
and kinking his air drive line, and, presumably, 
developing severe congestive heart failure. 
Total Heart Failure: Ventricular Fibrillation 
Three calves with LV blood pumps were stud- 
ied during accidental (1) or electrically induced 
ventricular fibrillation; 7 calves with LV and 
RV pumps were similarly studied, 1 in acci- 
dental and the other 6 in elective fibrillation. 
The calf with the LV pump fibrillated because 
of irreversible obstruction of the left coronary 
artery by the balloon cuff occluder. The calf 
with biventricular pumps fibrillated after left 
and right coronary microsphere infusion. 
All animals in ventricular fibrillation demon- 
strated the same findings. Those with LV blood 
pumps alone eked out a progressively dete- 
riorating existence from 45 minutes to 3 hours. 
Return of blood through the pulmonary circuit 
was not sufficient to supply the LV blood pump 
with a decent cardiac output. 
Of the 6 calves who were studied with bi- 
ventricular pumps, 4 had cardiac catheteriza- 
tion and were later studied awake in their stalls, 
during 4 hours, 9 hours, 32 hours, and 17 days 
of ventricular fibrillation. The LV and RV pump 
positions in the chest in these animals are il- 
