Myocardial strain/stress changes identified by echocardiography may reveal early sepsis-induced myocardial dysfunction

Abstract

Objective: To perform early assessment of sepsis-induced myocardial dysfunction (SIMD) using strain/stress echocardiography. Methods: A canine model of SIMD was established using intravenous injection of lipopolysaccharide (LPS, 2 mg/kg). Thirteen dogs were included, comprising an LPS-treated SIMD group (n = 7) and saline control group (n = 6). SIMD was assessed at various time-points using cardiac measurements including haemodynamics and echocardiography. Results: Systolic and radial ventricular wall stress and circular ventricular wall stress (WSsc) were significantly lower in the sepsis group versus the control group at all time-points. Logistic regression analysis revealed an inverse correlation between stress rate of the front-posterior and bottom wall and left ventricle systolic wall strength. In contrast, a positive correlation was found between the mean velocity of circumferential fibre shortening (mVCF) or heart rate-adjusted mVCF (RVCF) and WSsc. Using regression equations, predicted values for mVCF and RVCF in animals with sepsis were significantly higher than measured values at 4- 5- and 6-h time-points. Conclusions: These findings will further the understanding of pathophysiological alterations in SIMD at the early stage of sepsis, and suggest that strain rate may reflect the nature of myocardial contractility.