Ischemic stroke induces mild acute left ventricular dysfunction and ECG abnormalities in a mouse model of brain ischemia/reperfusion

BARBIERI I; FRANCO RIVEROS V; CASANOVA V; BUCHHOLZ B

Mar del Plata

Congreso; LXVIII Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC).; 2023

Objective: The aim was to determine if atransient ischemic stroke induces cardiac dysfunction through autonomicimbalance, due to sympathetic overactivity. Materials and Methods: Mice underwenttransient middle cerebral artery occlusion (tMCAo) for 60 min and 24hreperfusion. Gsalpha transgenic mice (TG) were used as a model of basal sympathetichyperactivity and were also exposed to tMCAo (I/R-TG). Left ventricularfunction (LVF) was assessed by echocardiography: ejection fraction (EF), shorteningfraction (SF) and isovolumetric relaxation time (IVRT). Electrocardiography(ECG) was performed throughout the ischemia and after 24h of reperfusion, toassess electric abnormalities. Infarct size (IS) was measured by TTC stainafter 24h reperfusion. Neurological deficit was assessed 4h and 24h after tMCAousing Longa’s scale (LS). Mortality was also assessed and compared betweengroups. Results: tMCAo produced similar IS in both experimental groups (I/R-NTG:30.0 ± 4.3 %, I/R-TG: 26.2 ± 5.0 %; p=NS). We observed LV dysfunction,characterized by a mild decrease in EF in NTG mice (I/R-NTG: 72.5±1.8% vs SHAMNTG: 87.4±1.0% p<0.05) and TG mice (I/R-TG: 81.4±1.5% vs SHAM TG: 87.3±1.3%p<0.05) and SF in NTG mice (I/R-NTG: 42.6±1.9% vs SHAM NTG: 51.3±1.8%p<0.05) and TG mice (I/R-TG: 44.8±1.4% vs SHAM TG: 49.8±1.5% p=NS). IVRTsignificantly decreased in the TG group (I/R-TG: 18.1±0.7ms vs I/R-NTG: 20.8±0.7ms;p<0.05). Prolonged QTc interval was observed after 60 min of ischemia (157.4±5.8ms)and persisted after 24h reperfusion (158.9±2.9ms) respect to basal (129.2±5.2ms;p<0.05) in the I/R-TG group. After 24h of reperfusion, 42.9% of the NTG micesurvived, compared to 26.7% of TG mice (p<0.05). Conclusion: tMCAo induces an acute mild LVdysfunction and ECG abnormalities after 24h reperfusion. A significant increasein the mortality rate was observed in TG mice.