Background: Brain death (BD) causes hemodynamic and neuroendocrine alterations including a catecholamine surge, which in turn causes histologic lesions in cardiac muscle such as contraction bands, focal mononuclear cell infiltrates and cardiomyocyte necrosis. These changes are likely to compromise heart function and could therefore also affect the graft response after heart transplantation. This study was designed to examine the catecholamine surge, the catecholamine release pattern and the histologic lesions traditionally described as characteristic of BD in hearts procured from BD donors.
Methods: After BD diagnosis, specimens were taken from the left ventricle (n = 50) for histologic examination. Arterial blood samples were collected from 40 of the donors at different time-points (1 hour before BD; on BD diagnosis; and 1, 2, 3 and 4 hours after BD) to determine catecholamine levels by high-performance liquid chromatography (HPLC).
Results: The three hormones examined showed above-normal levels (epinephrine 2.36-fold, norepinephrine 8.56-fold, dopamine 54.76-fold). Release patterns included epinephrine and dopamine peaks at the time of BD and a norepinephrine peak 1 hour later. Fifty percent of the BD donors showed contraction bands and 62% displayed cardiomyocyte necrosis, which was associated with focal mononuclear cell infiltrates in 18% of cases. In 40% of donors, colocalized apoptotic and necrotic damage was observed.
Conclusions: Differing extents of BD-associated cardiac lesions were observed in the donors, and >50% also showed apoptotic damage. The expected catecholamine peak at the time of BD was only detected for epinephrine and dopamine. Hormone increases were below those described in the literature, except for dopamine.