The preload recruitable stroke work relationship as a measure of left ventricular contractile dysfunction in porcine cardiac allografts

• Published in: European journal of cardio-thoracic surgery 2002-11, Vol.22 (5), p.738-745
• Main Authors: Ryan, Jonathon B., Hicks, Mark, Cropper, Jonathan R., Garlick, Sarah R., Kesteven, Scott H., Wilson, Michael K., Macdonald, Peter S., Feneley, Michael P.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cardiopulmonary Bypass; Disease Models, Animal; Heart Arrest, Induced; Heart transplantation; Heart Transplantation - methods; Ischaemia-reperfusion; Left; Linear Models; Medical sciences; Myocardial Reperfusion Injury - complications; Myocardial Reperfusion Injury - physiopathology; Myocardial stunning; Organ Preservation - methods; Preload recruitable stroke work relationship; Regression analysis; Stroke Volume; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the heart; Swine; Time Factors; Ventricular Dysfunction, Left - etiology; Ventricular Dysfunction, Left - physiopathology; Ventricular function
• ISSN: 1010-7940; 1873-734X
• DOI: 10.1016/S1010-7940(02)00526-2

Objective: Paradoxically, it has been reported that after 1.5–4 h of hypothermic ischaemic preservation there is complete recovery of contractile function in canine cardiac allografts, as assessed by the preload recruitable stroke work (PRSW) relationship. This raises questions about the suitability of the canine heart as a model for preservation research and the PRSW relationship as an end-point. The aim of the present study was to evaluate the PRSW relationship as an index of left ventricular contractility in porcine cardiac allografts. Methods: Eighteen orthotopic heart transplants were performed in inbred Westran pigs. Brain death was induced in the donor pigs 1 h prior to explantation. The donor hearts were arrested with extracellular cardioplegia, which was stored in ice prior to administration. On explantation, the donor hearts were immersed in cardioplegia and stored in ice. The donor hearts were subjected to either 4 (IT4, n=6), 6 (IT6, n=9) or 14 (IT14, n=3) h of ischaemia. Post-transplant, all hearts were supported with dobutamine (10 mcg/kg per min). The PRSW relationship was derived from pressure-volume loops obtained by epicardial sonomicrometry and transmyocardial micromanometry. Multiple linear regression was used to describe and compare the PRSW relationship before brain death in the donor and after weaning from bypass in the recipient. Results: Eleven hearts were weaned successfully from cardiopulmonary bypass: IT4 100% (6/6), IT6 56% (5/9) and IT14 0% (0/3) (IT4 versus IT14: P=0.012). Analysis of the PRSW relationship revealed a reduction in contractility in both the IT4 and IT6 groups (both P