The Annals of Thoracic Surgery, Vol 27, 7-12, Copyright © 1979 by The Society of Thoracic Surgeons
I. Development of an in vitro model of myocardial cooling: a study of the effect of cardiac size on cooling rate
FL Rosenfeldt and DA Watson
A physical model for the study of local cardiac hypothermia was developed
using excised animal hearts. The validity of the model was established by
showing close similarity between cooling curves of dog hearts in vivo and
in the model. The model was then used to compare the cooling rates of three
groups of excised hearts using cold saline irrigation. Groups 1, 2, and 3
had mean left ventricular weights of 166, 379, and 1,429 gm, respectively,
and mean left ventricular wall thicknesses of 1.5, 2.0, and 3.1 cm,
respectively. For the same 10 degrees C temperature fall, Group 1 took 25
+/- 2.8 minutes, Group 2 took 54 +/- 9.2 minutes, and Group 3 took 117 +/-
21 minutes. To avoid slow cooling and consequent ischemic damage in the
hypertrophic ventricle, it may be desirable to initiate cooling using
coronary perfusion with cold blood or cold cardioplegic solutions.