Correlation of cardiac function and cerebral perfusion in a murine model of subarachnoid hemorrhage

Cerebral hypoperfusion is a key factor for determining the outcome after subarachnoid hemorrhage (SAH). A subset of SAH patients develop neurogenic stress cardiomyopathy (NSC), but it is unclear to what extent cerebral hypoperfusion is influenced by cardiac dysfunction after SAH. The aims of this study were to examine the association between cardiac function and cerebral perfusion in a murine model of SAH and to identify electrocardiographic and echocardiographic signs indicative of NSC. We quantified cortical perfusion by laser SPECKLE contrast imaging, and myocardial function by serial high-frequency ultrasound imaging, for up to 7 days after experimental SAH induction in mice by endovascular filament perforation. Cortical perfusion decreased significantly whereas cardiac output and left ventricular ejection fraction increased significantly shortly post-SAH. Transient pathological ECG and echocardiographic abnormalities, indicating NSC (right bundle branch block, reduced left ventricular contractility), were observed up to 3 h post-SAH in a subset of model animals. Cerebral perfusion improved over time after SAH and correlated significantly with left ventricular end-diastolic volume at 3, 24, and 72 h. The murine SAH model is appropriate to experimentally investigate NSC. We conclude that in addition to cerebrovascular dysfunction, cardiac dysfunction may significantly influence cerebral perfusion, with LVEDV presenting a potential parameter for risk stratification.