Subarachnoid Hemorrhage-Triggered Acute Hypotension Is Associated with Left Ventricular Cardiomyocyte Apoptosis in a Rat Model.

Whether hypotension that occurs due to neurogenic stunned myocardium after subarachnoid hemorrhage (SAH) is associated with cardiomyocyte apoptotic cell death remains unknown. In this study, 18 male rats were subjected to sham or the endovascular perforation model of SAH surgery. Based on the mean arterial pressure (MAP) after SAH, rats were separated into SAH with hypotension (SAH hypotension) or SAH with blood pressure preservation (SAH BP preservation) groups. All animals were euthanized 2 h after the surgical procedure. Hearts were removed and separated transversely into base and apex parts, then Western blot analyses and immunohistochemistry were performed only in the apex part. One rat died as a result of severe SAH and two rats with mild SAH were excluded. We analyzed data from 15 rats that were divided into three groups: sham, SAH hypotension, and SAH BP preservation (n = 5, each). There was a significantly higher cleaved caspase-3/caspase-3 ratio in the SAH hypotension group compared with sham and the SAH BP preservation group. Cardiomyocyte apoptosis was demonstrated in the SAH rats. This is the first experimental report that describes SAH-induced neurogenic stunned myocardium with ensuing hypotension may result from the acute apoptotic cardiomyocyte cell death in the left ventricle.