Objective–In rodent models of subarachnoid hemorrhage (SAH), the impact of cardiac function on cerebral perfusion is unclear. We therefore set out to investigate the interplay between cerebral perfusion and cardiac function in a murine endovascular filament perforation model of SAH. A further aim of this study was to record abnormal ECG and echocardiography recordings as a basis for future experimental studies on neurogenic stress cardiomyopathy (NSC), which occurs in a significant number of SAH patients.

Methods–20 female C57BL/6-N mice were randomized either to induction of SAH by endovascular filament perforation or to sham surgery. Cerebral cortical perfusion was imaged using laser SPECKLE contrast imaging, along with determination of intracranial pressure. Cardiac function was assessed with 1-lead ECG recordings and high frequency small animal echocardiography. Measurements were performed at baseline, and 15 min, 3 h, 24 h, 72 h and 7 days after surgery. Blood pressure was determined non-invasively using a tail-cuff system.

Results–Baseline parameters were similar between SAH and sham. SAH induction was associated with significant reduction of cerebral perfusion, which mostly recovered by 24h. Blood pressure was similar between SAH and sham animals. Cardiac left ventricular function was enhanced during the first 72 h and reduced at 7 days compared to sham. In the SAH group, there was a significant positive correlation between left ventricular end-diastolic volume and cerebral perfusion between 3 and 72 h post-SAH. 3 SAH animals showed ECG-abnormalities such as right bundle branch block 15 min and 3 h after SAH, which recovered by 24 h. In contrast to the overall increase in LVEF in the SAH group, 2 SAH animals showed a prominent decrease in LVEF 3 h after SAH, which recovered by 24 h.

Conclusion–In the murine SAH model, SAH influences cardiac function, and end-diastolic filling appears to influence cerebral cortical perfusion markedly in the early period after SAH. The abnormal ECG and echocardiographic findings observed in single animals resemble those found in SAH patients with NSC, indicating that the murine model is suited for functional studies on NSC after SAH.