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Brain death impairs coronary endothelial function
Gabor Szabo1, Volker Buhmann, Susanne Bahrle
1Department of Cardiac Surgery, University of Heidelberg, Im Neueneheimer Feld 110, 69120 Heidelberg, Germany.
Insights
Brain death (BD) impairs coronary blood flow and causes endothelial dysfunction, negatively impacting cardiac transplant outcomes. This study in canines reveals significant changes in coronary circulation and vasomotor response post-BD.
Area of Science:
- Cardiovascular Physiology
- Transplantation Immunology
- Neurology
Background:
- Brain death (BD) poses challenges in cardiac transplantation.
- Endothelial dysfunction is a key concern in post-transplant outcomes.
- Canine models are utilized to study BD's effects on cardiovascular function.
Purpose of the Study:
- To investigate the impact of brain death (BD) on coronary circulation.
- To characterize endothelial dysfunction following BD in a cardiac transplantation context.
- To assess vasomotor function changes after BD induction.
Main Methods:
- Utilized a canine model to induce brain death via subdural balloon inflation.
- Continuously monitored left ventricular pressure-volume data and coronary blood flow (CBF).
- Assessed endothelium-dependent (acetylcholine) and endothelium-independent (sodium nitroprusside) vasodilation before and after BD.
Main Results:
- BD initially increased CBF, followed by a significant decrease after 3 hours.
- Endothelium-dependent vasodilation shifted from monophasic response to initial vasodilation followed by vasoconstriction post-BD.
- Endothelium-independent vasodilation remained unaffected by BD.
Conclusions:
- Brain death impairs coronary circulation, leading to decreased CBF and hemodynamic deterioration.
- Severe endothelial dysfunction post-BD is a significant factor contributing to adverse post-transplant outcomes.
- BD-induced endothelial dysfunction warrants further investigation in the context of organ transplantation.
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.