Cerebral Blood Flow Alteration Following Acute Myocardial Infarction in Mice

Heart failure is associated with low cardiac output (CO) and low brain perfusion that imposes a significant risk for accelerated brain aging and Alzheimer disease development. Although clinical heart failure can emerge several years following acute myocardial infarction (AMI), the impact of AMI on cerebral blood flow at early stages and up to 30 days following MI is unknown. 16 months old male mice underwent left anterior descending (LAD) coronary artery ligation. Hemodynamic analysis were performed at baseline and at days 1, 7, and 30 post-MI. Left ventricular (LV) ejection fraction, LV volumes, CO, and right common carotid artery (RCCA) diameter were recorded by echocardiography. RCCA flow (RCCA FL) was measured by Doppler echocardiography. LV volumes consistently increased (p=0.0012) and LV systolic function progressively deteriorated (p=0.0001) post-MI. CO and RCCA FL showed a moderate but significant decrease over the course of MI with similar fluctuation pattern such that both variables were decreased at day 1, increased at day 7, and decreased at 30 days post-MI. Correlation and regression analyses between CO and RCCA FL showed a strong correlation with significance at baseline and day 30 post-MI (R=0.71, p=0.03, and R=0.72, p=0.03, respectively). Days 1 and 7 analyses between CO and RCCA FL showed moderate correlation with non-significance post-MI (R=0.51, p=0.2, and R=0.56, p=0.12, respectively). In summary, cerebral blood flow significantly decreased following AMI and remained significantly decreased for up to 30 days, suggesting a potential risk for brain damage that could contribute to cognitive dysfunction later in life.