Tor Steensrud

MD, PhD

E-post
tors@fagmed.uit.no

Hovedoppgaver
Tor Steensrud, Dag Sørlie et al.

This project, Cardioprotection during surgery, is part of a larger study, studies of postoperative heart failure. The aim of the study is to evaluate some aspects of intraoperative cardioprotection.

Previous work here with warm blood cardioplegia given retrograde during ischemia has showed considerable reduction in infarct size compared to other cardiopelgia but also a shift in metabolism towards use of fatty acids, reduced cardiac function, wasting of MVO2 but despite this provide better protection than standard, cold, crystalloid hyperkalemic cardiac arrest.

This study is investigating if cardioplegia containing ATP channel openers can protect the heart better, either by providing an alternative method of achieving cardioplegic arrest or by activating the mitochondrial ATP channels and protect by preconditioning the heart.

Methods:
An open chest pig model on full cardiopulmonary bypass using blood as cadioplegic vehicle. Ventricular contractility and work is assessed by the use of conductance catheters, employing the time varying elastance model depicted by Suga and colleagues. Ventricular energetics are evaluated from the integrated use of conductance catheters, coronary flow measurements (ultrasonic flow probes) and coronary sinus blood gases. This is analyzed in the PVA/MVO2 framework. Cardiac biopsies are analyzed regarding ATP content, water content and ultra structure.