Intact coronary and myocardial functions after 24 hours of non-ischemic heart preservation

Abstract

<i>Objectives.</i> The aim of this study was to investigate endothelium dependent relaxation (EDR) in coronary artery and the myocardial contractility after 24 h of non-ischemic heart preservation (NIHP). <i>Design.</i> Explanted cardioplegic hearts from six pigs were preserved by NIHP for 24 h. The perfusion medium consisted of an albumin containing hyperoncotic cardioplegic nutrition-hormone solution with erythrocytes to a hematocrit of 10%. Coronary artery ring segments were then studied in organ baths. Thromboxane A₂ was used for vasocontraction and Substance P to elicit endothelium dependent relaxation. A heart trabecula from the right ventricle was mounted in an organ bath and a special stimulation protocol was used to characterize myocardial contractility. Fresh cardioplegic hearts from 11 pigs were used as controls. The water content of the hearts was calculated. <i>Results.</i> There was no significant difference between NIHP and fresh controls regarding EDR (91.2 ± 1.2% vs 93.1 ± 1.8%). The contraction force, potentiation and calcium recirculation fraction did not differ between the groups. The water content of the myocardium was 79.3 ± 0.2% for NIHP and 79.5 ± 0.2% for controls. <i>Conclusions.</i> NIHP for 24 h keeps coronary artery EDR and myocardial contractility intact and causes no edema.