Renal sympathetic denervation inhibites the development of left ventricular mechanical dyssynchrony during the progression of heart failure in dogs

Abstract

Objective To investigate whether transcatheter renal sympathetic denervation (RSD) by radiofrequency ablation interfere with the development of left ventricular (LV) mechanical dyssynchrony during the progression of heart failure (HF). Methods Nineteen beagles were randomly divided into sham-operated group (six dogs), control group (seven dogs), and RSD group (six dogs). Sham-operated group were implanted with pacemakers without pacing; Control group were implanted with pacemakers and underwent 3 weeks of rapid right ventricular pacing; and RSD group underwent catheter-based RSD bilaterally and were simultaneously implanted with pacemakers. LV dyssynchrony was analyzed via 2D speckle-tracking strain echocardiography to evaluate LV function.Longitudinal dyssynchrony was determined as the standard deviation for time-to-peak speckle-tracking strain on apical 4- and 2-chamber views. Radial and circumferential dyssynchrony was determined as the standard deviation for time-to-peak speckle-tracking strain in mid- and base-LV short-axis views. LV systolic pressure (LVSP) and LV end-diastolic pressure (LVEDP) were measured. The LV interstitial fibrosis was determined by histological analysis. Results After 3 weeks, all of the dogs in both the control and RSD groups showed greater LV end-diastolic volume compared with the sham-operated group; however, the dogs in the RSD group had a higher LV ejection fraction (LVEF) than the dogs in the control group (P<0.001). The LV systolic strains were higher in the RSD group than in the control group (P<0.001 for longitudinal, circumferential and radial strain, respectively). The levels of LV dyssynchrony were lower in the RSD group than in the control group (P<0.001 for longitudinal, circumferential and radial dyssynchrony, respectively). Compared with control group, RSD group had lower LV end-diastolic pressures and less fibrous tissue. Conclusions RSD inhibites the development of left ventricular mechanical dyssynchrony during the progression of heart failure in dogs. Key words: Echocardiography; Kidney; Sympathetic nervous system; Catheter ablation; Heart failure; Ventricular function, left; Ventricular dyssynchrony