Sinus heart rate turbulence in patients with different subtypes of essential hypertension

Objective To explore sinus heart rate turbulence (HRT) in patients with different subtypes of essential hypertension (EH), and analyze the relationship between HRT and autonomic nervous system function damage in these patients. Methods The study consisted of 107 patients with EH (EH group) and 46 controls (control group). Based on 24 hours dynamic electrocardiogram, all patients were divided into dipper,non-dipper,and anti-dipper blood pressure group. The indexes about HRT and heart rate variability (HRV) among these groups were calculated and compared,and the relationship between turbulence onset (TO),turbulence slope (TS) and 24 hours mean systolic blood pressure,diastolic blood pressure was analyzed. Results There were significant differences in TO,TS,SDNN between EH group and control group(P ＜ 0.05 ). TO in non-dipper and anti-dipper blood pressure group was significantly higher than that in control group( P ＜ 0.05 ), and TS was lower than that in control group(P ＜ 0.05 ). There was no significant difference in TO,TS between dipper blood pressure group and control group (P ＞ 0.05). TO in non-dipper and anti-dipper blood pressure group was significantly higher than that in dipper blood pressure group, but TS was lower than that in dipper blood pressure group (P ＜0.05). Correlation analysis showed that TO had positive relationship with average heart rate and age (rs = 0.265, P = 0.004;rs = 0.217, P = 0.018 ), but had negative correlation with SDNN and left ventricular ejection fraction (LVEF) (rx = -0.287,P = 0.002;rx =-0. 179, P = 0.049). Whereas, TS had negative correlation with average heart rate and age (r = -0.335, P =0.015 ;r = -0.238,P= 0.009), but had positive relationship with SDNN and LVEF(r = 0.540,P = 0.001 ;r =0.432,P = 0.001 ). Conclusions HRT of EH patients becomes significantly low. It suggests that the autonomic nerve function in EH patients be injured seriously. Key words: Hypertension;  Arrhythmia,sinus;  Heart rate turbulence