Heart rate variability and heart rate turbulence in newly diagnosed hypertension

HEART RATE VARIABILITY AND HEART RATE TURBULENCE INNEWLY DIAGNOSED HYPERTENSIONDR. CELAL K L TSUMMARYVentricular arrhythmia and sudden cardiac death (SCD) riskincreased in patients with hypertension. In our study, we aim to investigatethe place of heart rate variability (HRV) and heart rate turbulence (HRT) inSCD risk determination in newly diagnosed hypertensive patients withoutcardiovascular target organ damage.Thirty eight patients (average age 51±12 year, 26 women, 12 men)who had not hypertension diagnosis beforehand, who had not any cardiacdisease except for hypertension and who had not any cardiovasculartarget organ damage secondary to hypertension, were constitutehypertension group. Control group was constituted from 56 adult, healthyvoluntaries (mean age 49±12 year, 43 women, 13 men).When the hypertension group compared with control group, SDNNand SDANN values were found significantly decreased in hypertensiongroup (p=0.005, p=0.002, respectively). Significant positive correlationbetween SDNN and SDANN values were found in hypertension group(r=0.95, p<0.001). At least one of turbulence onset and turbulence slopevalues were found abnormal in 3 of 21 hypertensive patients and in 7 of 29control individuals (p=0.39). There was no significant difference betweenHRT parameters of groups (p=0.12). Significant moderate positivecorrelations were found between SDNN, SDANN, Triangular index andnocturnal decrease ratios of systolic and diastolic blood pressures inpatients with hypertension (r=0.39, p=0.02; r=0.48, p=0.003; r=0.39,p=0.02; r=0.48, p=0.002; r=0.44, p=0.006; r=0.57, p<0.001, respectively).Furthermore there were negative correlations between all time domainHRV parameters and heart rate. Heart rate was not correlated with HRTparameters.Cardiac autonomic functions in patients with hypertension impairedbefore cardiovascular target organ damage develops. HRT seems not tobe a sensitive method as HRV in determining SCD risk of hypertensivepatients without cardiovascular target organ damage.