PRELOAD-RECRUITABLE STROKE WORK RELATIONSHIPS AND DIASTOLIC DYSFUNCTION IN THE BRAIN-DEAD ORGAN DONOR

Background Acute graft failure is an important cause of morbidity and mortality in cardiac transplantation, and it may be associated with my ocardial changes that occur during brain death (ED). This study invest igates the changes in biventricular systolic and diastolic function th at occur after ED in a validated canine model. Methods and Results The hearts of 20 mongrel canines (23 to 31 kg) were instrumented with mic romanometers, flow probes, and dimension transducers to measure minor/ major axes as well as left and right ventricular (LV/RV) septum-to-fre e wall distances. LV/RV volumes were measured according to the shell s ubtraction method. LV/RV systolic function was analyzed by ventricular stroke work plotted versus end-diastolic volume during a caval occlus ion (preload-independent recruitable systolic work, PRSW). The nonline ar relationships between diastatic pressure (stress) and LV/RV septum- to-free wall distances and volumes (strain) from successive diastoles during caval occlusion were used to evaluate LV/RV diastolic mechanics . The Cushing phenomenon, hyperdynamic response, and diabetes insipidu s were observed in each animal after BD. Results are expressed as mean +/- SEM (P<.05 versus baseline, ANOVA, paired two-tailed Student's t test). Biventricular systolic function deteriorated significantly from baseline PRSW 6 to 7 hours after BD. The diastatic LV/RV pressure-dim ension relationships were significantly different after BD, indicating a decrease in ventricular chamber compliance during diastole. Conclus ions BD causes a significant loss of systolic and diastolic LV/RV func tion in the brain-dead, heart-beating cadaver, which may contribute to early postoperative cardiac graft failure in the recipient. These fin dings have significant clinical applications and may help to avoid sub optimal donor/recipient matches.