Brain death impairs coronary endothelial function.
BACKGROUND
To characterize the impact of brain death (BD) on endothelial dysfunction after cardiac transplantation we investigated coronary circulation and vasomotor function in a canine model.


METHODS
Left ventricular pressure-volume data (conductance catheter) and coronary blood flow (CBF) were monitored continuously. Endothelium-dependent vasodilatation after acetylcholine and endothelium-independent vasodilation after sodium nitroprusside were assessed before and 3 hr after BD induction (inflation of a subdural balloon).


RESULTS
BD led to an initial hyperdynamic reaction with significant (P<0.05) increase of CBF. After 3 hr, CBF decreased significantly (P<0.05). Although before BD, application of acetylcholine led to a monophasic vasodilatative response, after BD a short mild vasodilatation was followed by a longer vasoconstriction. Endothelium-independent vasodilatation remained unchanged.


CONCLUSIONS
BD affects coronary circulation by two means: (1) impairment of CBF to decrease in parallel in afterload with consecutive hemodynamic deterioration and (2) severe endothelial dysfunction that may be a contributing factor to posttransplant outcome.
Szabo
Gabor
G
Department of Cardiac Surgery, University of Heidelberg, Im Neueneheimer Feld 110, 69120 Heidelberg, Germany.
Buhmann
Volker
V
Bahrle
Susanne
S
Vahl
Christian F
CF
Hagl
Siegfried
S
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001926:Brain Death / Q000503:physiopathology*; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology; D003331:Coronary Vessels / Q000503:physiopathology*; D004285:Dogs; D004730:Endothelium, Vascular / Q000503:physiopathology*; D016027:Heart Transplantation; D006439:Hemodynamics / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D011183:Postoperative Complications / Q000503:physiopathology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine