ABSTRACT
Objective To evaluate the clinical significance of sinus heart rate turbulence(HRT)and the heart rate variability(HRV)in the patients with essential hypertension(EH).Methods HRV and HRT examination were carried out in sixty patients with EH.A subgroup of patients receive metoprolol+nifedipine(n=26)or nife- dipine alone(n=34)were investigated seperately to evaluate the effect of ?-blocker on the HRV and HRT.Fifty healthy persons were served as control.In the HRT determination,turbulence onset(TO)was defined as sinus heart rate acceleration,after ventrieular mature beat while turbulence slope(TS)as sinus heart rate deceleration slope after ventricular premsture beat.Normal value of TO was2.5 ms/RR period. SDNN,RMSSD,LF/HF in HRV were analysed from 24 hours ambulatory electrocardiography(before and after 1 month medication).Results ① In hypertensive group,52 patients showed positive TO(86.6%),48 patients pos- itive TS(80.0%)and 46 patients TO+TS(76.7%),compared with hypertension group only 2(4%)positive TO and 3(6%)positive TS in the healthy control.Forty-two cases SDNN(70.0%),41 cases RMSSD(68.3%)and 38 cases LF/HF(63.3 %)were positive in hypertensive group,while only 1(2 %)SDNN,1(2 %)RMSSD and 3(6 %) LF/HF in control. ② Metoprolol didn't change the positive percentage of parameters in HRT but parameters showing Heart rate variablity in HRV was decreased significantly found between TO,TS and TO+TS.Conclusion HRT and HRV is two indices for determination the dysfunction of autonomic nervous system in hypertension.?-re ceptor blocker inhibit sympathic activity,miligate the decreasing of HRV,but the bipbase accelerative and decelera- tive phenomena of HRT didn't change,HRT seems to be a more sensitive index for monitoring of autonomic sysfunc tion in hypertension.