Prolonged pulseless perfusion in unanesthetized calves
G. G. Johnston, F. Hammill, U. Marzec, D. Gerard, K. Johansen, R. B. Dilley and E. F. Bernstein
Nonpulsatile left ventricular (LV) bypass was achieved in nine alert,
active calves for periods of up to two weeks using a centrifugal blood
pump. Data were compared to prebypass control values and to results
obtained from seven calves that underwent nonthoracotomy, retrograde LV
cannulation, and pulsatile bypass for up to 35 days. Nonpulsatile flow
produced an increase in heart rate of 20% (P less than .05) and an increase
in aortic pressure of 10% (P less than .05). Cardiac output and systemic
vascular resistance were similar in both groups for three days; thereafter,
vascular resistance decreased as cardiac output progressively increased.
Serum renin, lactate, and pyruvate values remained normal; creatinine
clearances were not significantly different than control values, and there
were no significant changes in body weight. These data indicate no untoward
effects as a result of prolonged pulseless perfusion.
