Circumferential strain rate to detect lipopolysaccharide-induced cardiac dysfunction: a speckle tracking echocardiography study

Background: Lipopolysaccharide (LPS)-induced myocardial dysfunction is a widely used indicator to study septic cardiomyopathy (SC). This study investigated the efficiency of strain rate imaging (SRI) in detecting LPS-induced myocardial dysfunction. Methods: A total of 30 mice were randomly assigned to saline group (n=10), 10 mg/kg LPS group (n=10) and 20 mg/kg LPS group (n=10). Then at baseline, 6 and 20 h after LPS injection, 2-D and M-mode echocardiography were conducted with GE Vivid 7 ultrasound (il3L linear probe, 10.0–14.0 MHz) and Echopac PC software. Ejection fraction (EF) and fractional shortening (FS) were measured with M-mode tracings. Serum biochemical examination was then performed to evaluate sepsis-induced myocardial injury. Results: In LPS 20 mg/kg group, at 6 h after LPS injection, SRI found significantly decreased early diastolic strain rate (SRe, 1.76±1.05 vs . 3.18±0.83 unit/s, P vs . 3.18±0.83 unit/s, P vs . 55.36%±7.42%, P vs . 25.43%±4.32%, P Conclusions: SRI is useful to early assess LPS-induced cardiac deformation in mice. circumferential strain rate (SRcirc) is a sensitive indicator for LPS-induced myocardial injury in severe sepsis.