Evaluation of left ventricular systolic function after renal sympathetic denervation in beagles with heart failure by layer-specific two-dimensional speckle tracking imaging

Abstract

Objective To assess the left ventricular systolic function after renal sympathetic denervation(RSD) in beagles with heart failure by layer-specific two-dimensional speckle tracking imaging. Methods Twenty-three beagles were randomly divided into control group (8 dogs), URSD group (8 dogs) and RSD group (7 dogs). Control group was implanted with pacemakers without pacing, URSD group was implanted with pacemakers and underwent 3 weeks of rapid right ventricular pacing, and RSD group underwent catheter-based RSD bilaterally and was simultaneously implanted with pacemakers. All standard measurements were obtained from the left ventricular short-axis views at the levels of mitral annulus, papillary muscle and apex, and apical four-chamber, two-chamber, and long-axis views. The peak systolic longitudinal strain and circumferential strain of each layer of the left ventricle were measured by layer-specific two-dimensional speckle tracking imaging. Results After 3 weeks, all of the dogs in both the URSD and RSD groups showed lower left ventricular diastolic and systolic function compared with those in the control group, however, the dogs in the RSD group had a higher LV ejection fraction (LVEF) than the dogs in the URSD group(P<0.05). Compared with the control group, the global longitudinal strain, circumferential strain and radial strain all decreased significantly in URSD and RSD groups. The longitudinal strain of endo- and mid-cardium and the circumferential strain in endo-cardium were significantly higher in RSD group than those in URSD group(P<0.05). Conclusions Myocardial systolic function is impaired in dogs with heart failure, layer-specific two-dimensional speckle tracking imaging can provide effective tools to assess the left ventricular systolic function. Renal sympathetic denervation can improve the myocardial systolic function in dogs with heart failure. Key words: Echocardiography; Renal sympathetic nerve; Catheter ablation; Ventricular function, left; Layer-specific speckle tracking imaging