C. GRANT LA FARGE AND W. F. BERNHARD 
89 
CHRONIC BIVENTRICULAR BYPASS 
Figure 9. — Pressure recordinprs obtained after 19 days 
of microsphere-induced left ventricular failure. Non- 
pumping, control state (OFF, left) represents clinical 
state of cardiogenic shock. Pumping state (ON, right) 
demonstrates restoration of Ao pressure to normal, 
and reduction of RV and LV pressures to low levels, 
with increase in cardiac output from 4.8 to 6.1 L/min. 
RV,LV = right and left ventricular peak and end- 
diastolie pressures. Ao = aortic pressure, mean in 
parentheses. 
creases due to an additional right atrial contri- 
bution to right ventricular pump filling.^ 
Finally, the left ventricular function data, 
painstakingly calculated from high-fidelity pres- 
sure recordings and biplane angiograms, are 
essentially the same for acute, reversible fail- 
ure (Figures 1-6) as they are for the acute 
phase of chronic, irreversible failure: the LV 
end-diastolic and end-systolic volumes increase 
to the same extent, the ejection fraction, LV 
end-systolic and aortic pressures fall to the same 
extent, and the restoration by pumping towards 
normal is to the same extent (Figure 6) in both 
types of failure. 
There are few mechanical blood pumps avail- 
able today which are as capable as those re- 
ported here of reversing the failure state (to 
64 days), or the total failure state (to 17 days 
of ventricular fibrillation), or of continuing 
partial bypass at 4.5 to 9 L/min for periods of 
time up to 203 days. The important point, how- 
ever, is that this LV and RV pumping system 
CHRONIC BIVENTRICULAR BYPASS 
ECG *i 
iZO)* 100-1 
mmHg 
LV 
Ao 
HR 
PUMP SV 
95/24 
95/62(80) 
85 
20/5 
150/94(120) 
67 
90 
Calf 236 
Figure 10. — Pressure recordings obtained after 19 days of microsphere-induced left ventricular failure. 
Non-pumping, control state (OFF, left) represents clinical state of pulmonary venous hypertension. 
Pumping state (ON, right) demonstrates restoration of aortic pressure to normal, and reduction of 
LV pressures to low levels, with increase in cardiac output from 5.1 to 6.0 L/min. LV = left ventric- 
ular peak and end-diastolic pressures. Ao = aortic pressure, mean in parentheses. HR = heart (and 
pump) rates. Pump SV = pump stroke volume. 
