Résumé
Objective To evaluate the synchrony of heart after catheter-based renal denervation by two dimensional speckle tracking imaging.Methods Each renal sympathetic nerve of 20 dogs were ablated,and the index of heart and blood pressure were detected 6 weeks later.Standard 2D images were acquired in the 2-,3-and 4-apical views.The times from QRS onset to peak-systolic strain rate and to peak-diastolic strain rate were measured for the longitudinal 16-segments in Qlab software,and the standard deviation were calculated.The time to peak longitudinal strain rate and time to peak contraction strain rate of left atrium were measured for each segment contained septal,latera,anterior and posterior in the level of the basal segments,middle sections and apical in Qlab software,and the standard deviation were calculated.Parameters were compared among the before and after of the ablation.Results The systolic pressure and diastolic pressure had no changes after the ablation of renal sympathetic nerve (P ＞ 0.05).The R-R showed a increasing trend,but no significant differences(P ＞0.05).The peak time of LV systolic and diastolic strain rate had a extended trendency too,but no differences(P ＞0.05),and standard deviations of the peak times had no significant differences(P ＞0.05).The peak time of LA longitudinal strain rate and contraction strain rate had a extended trendency,but no obvious change (P ＞0.05),and the standard deviations of the peak times had no significant differences (P ＞0.05).The size of the heart cavity had no differences(P ＞0.05).Conclusions The systolic pressure and diastolic pressure have no changes after the ablation of renal sympathetic nerve,and the synchrony parameters of LV and LA have no significant differences,demonstrate that the synchrony of heart is not affected by the renal sympathetic denervation.
Résumé
Objective To evaluate the security of catheter-based renal denervation by two dimensional speckle tracking imaging.Methods 20 dogs was ablated,whose indicies of heart and blood pressure were detected 6 weeks later.Standard 2D images were acquired in the 2-,3-and 4-apical views as well as the parasternal short-axis views at the level of the mitral valve and papillary muscles.The time to peak-systolic strain of each segment in the level of the mitral valve and papillary muscles,the standard deviation of the time to peak-systolic strain,the peak strain of the longitudinal 12-segment were recorded.Parameters were compared among the before and after ablation.Results Compared with before ablation of renal sympathetic nerve,the systolic pressure and diastolic pressure didn't reduced significantly after the ablation of renal sympathetic nerve (P ＞ 0.05),while there were no significant difference in the peak strain of the longitudinal 12-segment,the dyssychrony parameters and the size of the heart cavity before and after ablation(P ＞0.05).Conclusions The pressure had no change after the ablation of renal sympathetic nerve while without harmful effect on the the size of the heart cavity,the function of the myocardial contraction and the dyssychrony parameters.The ablation of renal sympathetic nerve can' t lower the normal blood pressure and be safe for heart at the same time.