CHANGES IN LEF=T VENTRICULAR HEMODYNAMICS AND 
DIMENSIONS DURING REJECTION OF THE ORTHOTOPICALLY 
TRANSPLANTED CANINE HEART 
E. B. Stinson, P. L. Tecklenberg, J. F. Hollingsworth and K. W. Jones* 
At the time of orthotopic cardiac transplantation in 
fourteen dogs an indwelling arterial pressure catheter 
was inserted into the recipient aorta and an electromag- 
netic flow transducer placed around the donor aorta. 
Serial electrocardiographic and hemodynamic studies 
were performed immediately postoperatively and then 
twice daily until rejection. Immunosuppressive drugs 
were not given. In an additional four dogs a miniature 
solid-state pressure transducer was placed within the 
transplanted left ventricle (LV) and endocardial pie- 
zoelectric crystals across the maximum transverse LV 
diameter; these animals were studied immediately and 
then daily until death. 
Immediately postoperatively stroke volume and car- 
diac output were severely depressed (6.0 ml and 41.6 
ml/kg/min), but then rose progressively over the next 
48 to 72 hours by 93 and 76% respectively; heart rate 
declined during this time from 133 to 102 beats/min. 
Arterial blood pressure showed no significant changes 
from the time of operation until shortly before death. 
Peak LV systolic pressure and dP/dt were stable during 
the early postoperative period; calculated ejection frac- 
tion and peak circumferential fiber shortening rate in- 
creased over the first 24 hours from 0.55 to 0.64 and 
from 2.6 to 2.9 circs/sec, respectively, and thereafter 
remained stable until rejection. 
Average survival was 6.5 days (± .6 S.E.). At the 
time of onset of acute rejection, as defined by a pro- 
gressive decrease in electrocardiographic voltage (one 
to four days before death), there were no consistent de- 
tectable changes in hemodynamics or LV dimensions. 
Subsequently, in the preterminal period, stroke volume 
and cardiac output declined to 5.9 ml and 34.5 
ml/kg/min, respectively. Ejection fraction and peak 
VcF diminished to 0.56 and 1.9 circs/sec, respectively. 
Peak LV and arterial pressure and LV dP/dt were 
well-maintained until terminal collapse of the animals. 
These studies indicate that at rest the pumping per- 
formance of the transplanted heart is not detectably im- 
paired until rejection injury is advanced, and thus 
hemodynamic observations offer little aid in the early di- 
agnosis of rejection. 
INTRODUCTION 
Although clinical observations,^ as well as 
isolated hemodynamic findings,^ after cardiac 
♦ Clinic of Surgery, National Heart & Lung Institute Bethesda, 
Maryland 20014. 
transplantation in man suggest that ventricular 
performance deteriorates progressively during 
the course of acute graft rejection, serial stud- 
ies of cardiac function during this period have 
not been presented in detail. In the investiga- 
tion described below, changes in hemodynamic 
status and alterations in left ventricular inter- 
nal transverse diameter were studied in dogs 
during acute rejection of the orthotopically 
transplanted heart. 
METHODS 
Orthotopic cardiac transplantation was per- 
formed in 14 dogs by the method of Lower and 
Shumway.^'^"^^ Donor-recipient pairs were 
matched only for approximate size. No drugs 
beside antibiotics (penicillin and streptomy- 
cin), and in some cases a single intraoperative 
dose of digoxin, were given at the time of oper- 
ation or thereafter. Donor hearts were electri- 
cally paced via atrial leads at 140-160 beats per 
minute for 24-48 hours postoperatively except 
during periods of study. 
In 10 animals a snug-fitting electromagnetic 
flow transducer was placed at the time of trans- 
plantation around the aorta or pulmonary ar- 
tery of the graft ; when the aorta was utilized, a 
thin mesh of Dacron was placed beneath the 
proximal edge of the flow transducer to prevent 
erosion (this did not significantly affect calibra- 
tion) . In addition, a wide-bore polyvinyl catheter 
(lOF) was inserted into the recipient's left car- 
otid or subclavian artery to the level of the 
aorta. The flow transducers were calibrated 
with saline or blood before and after implanta- 
tion, and paired calibrations were essentially 
identical. 
In four additional animals instruments were 
implanted at the time of operation to permit 
measurement of left ventricular pressure and 
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