Variations and clinical implications of heart rate turbulence parameters in hypertension

Objective To investigate the variations and clinical implications of heart rate turbulence (HRT) parameters, including the both recently developed (turbulence timing, TT) and classic ones (turbulence onset [TO] and turbulence slope [TS]), in hypertension and to identify their correlations with age, mean heart rate, standard deviation of normal-to-normal RR intervals (SDNN), left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVED). Methods TT, TO, TS and SDNN were measured and compared in 73 patients with hypertension and 55 healthy controls by the MGY software using 24-hour dynamic electrocardiogram (Holter) records. Data on LVEF and LVED were obtained using echocardiography. Correlations of TT, TO and TS with age, mean heart rate, SDNN, LVEF and LVED were analyzed. Results Patients with hypertension showed significantly higher TO and TT (both P0.01), lower TS and SDNN as compared with controls (both P0.01). There were significant correlations between TO and LVEF (r=-0.362, P0.05), TO and age (r=0.249, P0.05), TS and mean heart rate (r=-0.261, P0.05). Conclusion HRT appeared significantly blunted in patients with hypertension, suggesting evidenced damage to autonomic nerve function in this condition. TT may be promising as a new effective indicator of HRT.