The Journal of Thoracic and Cardiovascular Surgery, Vol 86, 364-372, Copyright © 1983 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Pulmonary artery balloon counterpulsation for right ventricular failure. An experimental evaluation
GK Jett, LG Siwek, AL Picone, RE Applebaum and M Jones
Right ventricular (RV) failure frequently occurs in patients undergoing
correction of congenital cardiac defects, as well as in other clinical
settings. RV hypertrophy was created in 10 neonatal lambs by pulmonary
artery (PA) banding. Twelve months later RV hypertrophy was present (RV
weight/body weight = 2.71 +/- 0.31 gm/kg); RV systolic pressures were
elevated (65 +/- 9 mm Hg) and the average gradient across the PA band was
38 +/- 9 mm Hg. RV failure was produced in all animals by performing a
right ventriculotomy. Four unassisted (control) animals died shortly after
separation from bypass. Six experimental animals underwent pulmonary artery
balloon counterpulsation (PABCP). A Dacron graft anastomosed to the
proximal PA served as a reservoir for a 40 ml intra-aortic balloon pump
system. PABCP effectively reversed RV failure, low cardiac output, and
systemic arterial hypotension. Periods with PABCP on and off in each animal
were compared. PABCP increased cardiac output from 1.45 +/- 0.16 to 2.03
+/- 0.13 L/min (p less than 0.0001) and increased aortic systolic pressure
from 78 +/- 7 to 99 +/- 6 mm Hg (p less than 0.0004). PABCP produced a
significant reduction in RV peak systolic pressure from 56 +/- 5 to 41 +/-
3 mm Hg (p less than 0.0001). PA peak pressure distal to the band increased
from 31 +/- 2 to 40 +/- 1 mm Hg (p less than 0.0001). Right atrial pressure
decreased from 14 +/- 1 to 11 +/- 1 mm Hg (p less than 0.0001) with PABCP,
and RV end-diastolic pressure fell from 15 +/- 1 to 11 +/- 1 mm Hg (p less
than 0.0001). RV stroke work index increased 49% from 0.081 +/- 0.011 to
0.121 +/- 0.017 gm X m/kg/beat (p less than 0.01), and RV systolic pressure
time index decreased 38% from 1140 +/- 79 to 710 +/- 65 mm Hg sec/min (p
less than 0.0001). Thus PABCP in the presence of RV dysfunction can produce
substantial improvement in RV function and in overall cardiac function and
may prove clinically useful in managing patients in refractory RV failure.