POINCAR PLOT INDEXES OF HRV IN CHRONIC KIDNEY DISEASE PATIENTS
Introduction: Sympathetic overactivity and prevalence of cardiovascular disease are high in patients with chronic kidney disease (CKD).The standard method for analyzing heart rate variability (HRV) include: statistical (time domain), power spectral (frequency domain) and nonlinear geometrical analysis. The Poincaré plot analysis is a geometrical and nonlinear method to assess the dynamics of HRV. It is a diagram in which each R-R interval is plotted as a function of the previous R-R interval define a point in the plot. In the Poincaré plots, the SD1 width reflects the parasympathetic activity and the SD2 length reflects the sympathetic modulation.
Aim: In this study we examined that this new method may assess the sympatho-vagal fluctuation in patients with chronic kidney disease (CKD).
Methods: Twenty-six patients with CKD were allocated for the study. The Poincaré plot is a quantified by measuring SD1, SD2 and SD1/SD2. Power spectral analyses were performed and LF, HF and HF/LF were calculated.
Results: All spectral and time domain parameters were lower in CKD patients compared to control ( p<0.05). HF reflecting vagal activity and it was significantly depressed in patients with CKD and hemodialysis patients. SD1 and SD2 indexes were significantly lower compared to control (p<0.05). The Poincaré plot indexes measured from CKD patients were smaller than ones measured from healthy subjects. In those patients the SD1/SD2 ratio decreased in hemodialysis patients compared to control (p<0.05).
Conclusion: Non linear HRV analysis was indicating severe autonomic dysfunction in CKD patients and those parameters were more sensitive tests compared to frequency domain analysis.