The Research Of Relationship Between The Regression Of Left Ventricular Hypertrophy And Amelioration Of Heart Rate Turbulence In Essential Hypertension With Left Ventricular Hypertrophy

HRT is the phenomenon of short-term fluctuation in sinus cycle length over a 10- to 15-beat period that follows a ventricular premature complex (VPC). After a VPC, when the autonomic function is normal, heart rate increases for several beats and then decreases for several beats before returning to baseline. When the patient is suffered from autonomic failure, heart rate turbulence is blunted or abolished. HRT can be quantified by two parameters: turbulence onset(TO), describing an early acceleration phase, and turbulence slope(TS), describing a late deceleration phase of heart rate after ventricular premature beat. TO is defined as the difference between the mean duration of the first two sinus beats following a VPC and the mean duration of the last two sinus beats preceding VPC, dived by the mean duration of the last two sinus beats preceding VPC. TO>0% corresponds to sinus rhythm deceleration after a VPC and TO<0% to sinus rhythm acceleration after a VPC. The optimal dichotomy for TO was 0%. TS is defined as the maximum positive slope of five subsequent RR intervals within the first 20 sinus rhythm intervals after a VPC. TS>2.5 ms per RR interval corresponds to sinus rhythm deceleration after a VPC and TS<2.5 ms per RR interval to no sinus rhythm deceleration after a VPC. The optimal dichotomy for TS was 2.5 ms per RR interval. It is reported that patients with normal autonomic nervous system has normal heart rate turbulence, but for those autonomic failure patients, heart rate turbulence is blunted or abolished. The drug interaction can ameliorate the left ventricular mass, prevent the cardiovascular events。A high proportion of autonomic failure patients with left ventricular hypertrophy have abnormal heart rate turbulence parameters. It is reported that essential hypertension patients accomplished with left ventricular hypertrophy have apparent autonomic failure, so we hypothesize that after the therapy, the regression of the left ventricular hypertrophy and the amelioration of heart rate turbulence has apparent relationship. Our purpose is to investigate the relationship between regression of left ventricular hypertrophy and amelioration of turbulence parameters.44 essential hypertension patients with left ventricular hypertrophy were enrolled into the study. The echocardiography and 48-hour electrocardiogram (ECG) Holter monitoring was performed at admission. The left ventricular mass index and turbulence onset, turbulence slope was obtained from them. Six months later, the examinations were carried out again and the regression of the above variables were examined and investigated if they have correlation between each other. Another group of 20 patients who underwent 48-hour Holter ECG monitoring for unspecified palpitation or chest discomfort and who had no proven heart disease was selected for comparison,obtain heart rate turbulence variables(TO,TS).For the essential hypertension patients with left ventricular hypertrophy, the heart rate turbulence variables have statistically differences compared with the control group, P<0.01, it shows that the essential hypertension patients with left ventricular have apparent autonomic failure. After six months of drug therapy, the patient has apparent left ventricular hypertrophy regression and amelioration of heart rate turbulence. The conclusions shows that after therapy of anti-hypertrophy, the left ventricular hypertrophy and the turbulence onset, turbulence slope ameliorated apparently and P<0.01 and was considered statistically significant. In Pearson's correlation analysis, left ventricular mass index was found to be directly correlated with TO(r=0.606, P=0.000), TS(r=0.356, P=0.018). After six months of drug therapy , the heart rate turbulence parameters of the essential hypertension with left ventricular hypertrophy still have statistically differences compared with the control group, P<0.01, shows that the essential hypertension with left ventricular hypertrophy still have autonomic failure in certain degree.Conclusions: The heart rate turbulence parameters of the essential hypertension with left ventricular hypertrophy were statistically different compared with the control group. After six months of drug therapy, the regression of left ventricular hypertrophy and amelioration of heart rate turbulence parameters were apparent and they have apparent relationship between each other. After the therapy, the heart rate turbulence parameters of the essential hypertension with left ventricular hypertrophy were still statistically different compared with the control group. It shows that essential hypertension patients with left ventricular hypertrophy have autonomic failure, after the therapy, autonomic failure can ameliorate apparently but still abnormal in certain degree.