Left ventricle ejection fraction is initially depressed and subsequently recovers after lipopolysaccharide (LPS) administration. (A) Kaplan–Meier diagram showing mice survival after challenge with LPS doses of 4 (n = 6 mice) and 7 μg/g (n = 17 mice). (B) M-mode echocardiography stills for mice at baseline (BL; left), 12 h (middle), and 3 days (right) after administration of 7 μg/g of LPS. Arrows show the main parameters measured: the systolic and diastolic anterior wall thickness (AW_S and AW_D, respectively), posterior wall thickness (PW_S and PW_D), and left ventricle internal diameter (ID_S and ID_D). Total wall thickness was calculated as AW_D + PW_D. Left ventricle ejection fraction was calculated from the ID_S and ID_D measurements, using VisualSonics (Canada) software. (C–F) Average results of a serial echocardiography study in a cohort of six mice that survived LPS challenge (7 μg/g). Studies were performed at baseline, 12 h after LPS administration, and at day 3. Data are shown as mean ± SD. Data from mice that died before day 3 are not included in this analysis and are shown in figure 6. Shown are left ventricle ejection fraction (C), total wall thickness (D), and internal diameter (E). Heart rate (F) was similar between groups. *P < 0.05 versus baseline.