Quantitative evaluation of left ventricular function in immobilization stress model of rats with two-dimensional speckle tracking echocardiography
Liu Xiaoran
Ma Ning
Li Rongjuan
Yang Ya
Abstract：Objective To quantitatively evaluate the left ventricular function in immobilization stress (IMO) model of rats with two-dimensional speckle tracking echocardiography technique.Methods Forty-eight female Sprague Dawley rats (aged 30 weeks) were randomly divided into observation group (n =36) and control group (n=12);the rats in observation group were further randomly divided into instant, 24 h, 48 h, 72 h subgroup (n =9 in each group).IMO model was established by binding for 30 min in observation group, and the rats in control group were free movement.Echocardiography was performed immediately, 24 h, 48 h and 72 h after relief of stress in each subgroup.The interventricular septal thickness, left ventricular posterior wall thickness, left ventricular end diastolic dimension (LVEDD), left ventricular end systolic dimension (LVESD), left ventricular ejection fraction, fractional shortening, stroke volume (SV), end-systolic volume and left ventricular end-diastolic volume were determined;the images of left ventricular long axis plane (base, mid, apex of anterior septum and posterior wall) and left ventricular short axis plane (anterior wall, lateral wall, posterior wall, inferior wall, posterior septum, anterior septum) were saved, the radial strain and strain rate, longitudinal strain and strain rate, circumferential strain and strain rate, systolic peak velocity of 12 segments were analyzed with two-dimensional speckle tracking echocardiography.Results The different degree of abnormalities in the electrocardiogram were observed in all the animals in observation group, with obvious ST segment elevation in 9 rats [25.0％ (9/36)].Left ventricular apex regional wall motion dysfunction occurred in 1 rats in echocardiography.The LVESD in 24 h subgroup was significantly lower than that in 72 h subgroup [(3.76 ± 0.82) mm vs (4.37 ± 0.58) mm], the LVEDD and SV in 24 h subgroup were significantly lower than those in control group and 48 h subgroup [(7.40 ±0.61) mm vs (7.81±0.39), (7.99 ±0.27) mm;(228 ±41) ml vs (260 ±36), (265 ±26) ml] (P ＜ 0.05);the other heart function indexes were not significantly different among groups (P ＞ 0.05).The radial strain, strain rate and systolic peak velocity, the longitudinal strain, strain rate and systolic peak velocity of apex section in anterior septum, the radial strain and strain rate, the circumferential strain and strain rate of posterior wall in instant subgroup were significantly lower than those in control group [(19.36 ± 5.75) ％ vs (37.31 ±9.97)％, (3.67±1.67) s-1 vs (7.18 ±2.04) s-1, (0.65 ±0.44) cm/s vs (1.21 ±0.41) cm/s,(-14.63±6.98)％ vs (-25.43 ±2.07)％, (-3.33±0.67) s-1 vs (-6.31 ±0.96) s-1, (0.54±0.34) cm/s vs (1.04±0.88) cm/s, (21.27±8.16)％ vs (44.40 ±7.86)％, (5.02±0.89) s-1 vs (8.24± 0.48) s-1, (-16.91 ±8.08)％ vs (-24.27±9.49)％, (-4.21 ±0.46) s-1 vs (-7.00±0.80) s-1] (P ＜0.05).Conclusions Reversible segmental contraction dysfunction occurres on partial segments of left ventricular wall after stress in IMO rats, which can be detected by speckle tracking echocardiography more early and sensitively compared with M model echocardiography.
Keywords：Stress cardiomyopathyStrainSpeckle trackingEchocardiography
Publication Date：2016-01-30
Online Publishing Date：2026-09-14(First online date of this platform, not the publication date of the document)
Pages：6( 10-15 )