The Annals of Thoracic Surgery, Vol 41, 260-264, Copyright © 1986 by The Society of Thoracic Surgeons
Study on myocardial contractility after cardiopulmonary bypass versus cardioplegic arrest in an air-ejecting in vivo heart model
AM Addetia, SV Lichtenstein, AS Ko, M Sikkonen, M Sainani and TA Salerno
Cardiac function was assessed in a working in vivo canine heart
preparation. Minute work and myocardial oxygen consumption (MVo2) were
measured after a two-hour period of hypothermic hyperkalemic crystalloid
cardioplegic arrest in one group of dogs (Group 1, N = 6) and in another
group of dogs on cardiopulmonary bypass (CPB) alone (Group 2, N = 6).
Results indicate that at an afterload of 50 cm H2O, minute work was the
same in all hearts but MVo2 was significantly higher in Group 1 hearts at
all levels of preload. At higher afterloads, both minute work and MVo2 were
significantly greater in Group 1 hearts over the range of preloads tested.
Ventricular compliance was decreased in Group 1 over the range of preloads
studied. These results suggest that hearts undergoing cardioplegic arrest
had better left ventricular contractility than hearts undergoing CPB alone.