C. GRANT LA FARGE AND W. F. BERNHARD 
REVERSIBLE LV FAILURE - CORONARY CUFF METHOD 
79 
EC6 
LVANDAo 
PRESSURE 
mmHg 
50 
LVED 
PRESSURE 
mmHg 
ON- 
H OFF 
Calf 4^ ISO 
I 
Ao(mmHg)- ■ -116/104 50/40 116/94 
LV(mmHg)- ■ 116/0 50/30 116/0 
HR(bpm) • ■ ■ 75 94 • ' 80 
Figure 4. — Recordings of electrocardiogram (Ecg), aortic (Ao), and left ventricular (LV) pressures during 
(left) and following (right) induction of acute, reversible LV failure by inflation of a balloon cuff occluder 
around the left main coronary artery. HR = heart rate. 
Sixteen rats were given a 2.5% solution of 
cobaltous chloride: 3 intra-peritoneally, 3 sub- 
cutaneously, and 6 v^r os, with 4 controls. Fol- 
lowing this, 10 dogs were studied with the same 
2.5% cobaltous chloride solution: 5 animals 
were injected subcutaneously with 10-20 mg/ 
Kg daily; 2 were injected intraperitoneally with 
1-2 mg/Kg daily; and 3 were given 10-20 mg/ 
Kg per OS, daily. 
All rats, at death or sacrifice, were autopsied, 
and hearts dissected and weighed by standard 
techniques, as were the dogs'. Cardiac catheteri- 
zation with angiography, under pentobarbital 
anesthesia, were performed in 4 dogs surviving 
7 to 21 days. 
LV Failure— Chronic: Microsphere Infusion 
A profound state of LV myocardial failure 
was produced reliably and free of arrhythmias 
in a series of experiments in isolated, supported 
canine hearts reported from our laboratory.^i 
The technique was adapted for calves, and has 
been used to induce LV failure in 2 control ani- 
mals, 8 calves with LV blood pumps, and 4 
calves with LV and RV blood pumps. Two addi- 
tional calves were studied with RV (1) and 
biventricular (1) failure; the former had an 
LV pump alone, the latter a biventricular sys- 
tem. 
After 8 to 44 days of continuous partial by- 
pass, cardiac catheterization was performed. 
During this study, 10 to 20 ml of a 3% solution 
of microspheres (divinylbenzene copolymer 
latex, 6-14 microns in diameter) were infused 
into the left main coronary artery in 1 ml in- 
crements every 3 minutes. The end-point of 
infusion was determined by arrival of the 
LVedp at 30-40 mmHg (25 mmHg for con- 
trols). Subsequent hemodynamic measurements 
and biplane angiograms were recorded, and the 
animals returned to the animal farm for fur- 
ther study. 
Subsequent studies (after 4 to 64 days of 
microsphere-induced failure) included repeat 
cardiac catheterizations (10), pressure and flow 
measurements in stall, awake (5), and graded 
treadmill exercise (3). Those animals which 
have been sacrificed (2 animals alive at this 
time, at 46 and 79 days, with LV pumps) have 
been autopsied. The hearts have been dissected, 
