C. GRANT LA FARGE AND W. F. BERNHARD 
81 
LEFT VENTRICULAR FA I LURE - ACUTE (CO2 ) 
CONTROL 
p-7 min - COz 
BIPLANE- 
ECG- 
100- 
LV PRESSURE 
(mmHg) 
p-8 min -RECOVERING 
RECOVERY 
LV PRESSURE 
(mmHg) 
CALF # 50 (Cell) 
Figure 1. — Pressure recordings in a control calf showing: baseline left ventricular 
pressure (125/0-4 mmHg) and electrocardiogram (upper left) ; induction of fail- 
ure by CO2 infusion (120/26-35 mmHg) with marked Ecg changes (upper right) ; 
post-biplane angiogram (Figure 3) recordings of recovery phase (lower left); 
and, late recovery phase (130/0-5 mmHg; lower right). 
control calf, the cuff was alternately inflated 
(on, left) and then deflated (off, center), after 
the steady failure state had been produced. 
This technique was used in 3 calves with im- 
planted LV blood pumps, as illustrated in Fig- 
ure 5. Control LV pressure (115/8 mmHg) is 
altered by the coronary occlusion to 75/35 
mmHg, while aortic pressure falls to 75/56 
mmHg. The left ventricular quickly restores 
Ao pressure to 135/95 mmHg and reduces LV 
pressure to 30/8 mmHg. 
Pressure-volume work diagrams were cal- 
culated for all 4 hemodynamic states in this 
calf (Figure 5): control and pump-assisted; 
normal and failure. Calculated from simul- 
taneously recorded high-fidelity pressures and 
angiograms, the 4 work diagrams are illus- 
trated in Figure 6. Each diagram is identified 
as to the state in which it was recorded, in the 
upper right hand corner, and the tabular data 
appear in Tables I and U. Similar work dia- 
grams calculated for every calf in this group 
show the same effects as illustrated here, both 
for normal and failure states. 
LV Failure— Chronic: Microspheres 
The technique of producing profound myo- 
cardial failure by infusion of microspheres into 
the coronary artery actually provided the op- 
portunity for the study of all physiological states 
desired: normal (non-failing) ; during the acute 
phase of myocardial failure ; at intervals during 
long-term, gradually compensating failure (up 
