The Change And Prognostic Value Of Heart Rate Turbulence In Elderly Patients With Chronic Heart Failure

Background and Objective There is a high risk of sudden cardiac death (SCD) in elderly patients with chronic heart failure (CHF). Recently some scholars proposed a phenomenon, which the heart rate turbulence weakens even vanishes, was observed in patients with CHF .Heart rate turbulence (HRT), defined as a biphasic acceleration–deceleration response of a sinus node triggered by a ventricular premature complex, has proved to be a predictor of mortality in post infarction patients. The predictive value of HRT for mortality in patients with CHF remains controversial. There are limited data regarding the association between HRT parameters and the comprehensive evaluation of left ventricular (LV) dysfunction and CHF indexes in patients with CHF. HRT is considered a vagally dependent effective measure of barore?ex sensitivity, and as such is expected to be related to the advancement of CHF. The aim of this study was to evaluate the association between HRT parameters and clinical, biochemical, echocardiographic, and electrocardiographic measures of CHF in a large, prospectively enrolled population of patients with CHF to determine whether HRT could be considered a marker of CHF advancement and progression, giving insight into hemodynamic changes as well as changes of the autonomic nervous system.Patients and Methods 66 CHF patients and 40 health person were enrolled (mean age 68 years) in the study. The following tests were performed: 12-lead surface electrocardiography, 24-hour Holter, echocardiography, chest x-rays, B-type natriuretic peptide levels, Heart rate variability (HRV), mean heart rate Turbulence onset (TO) and turbulence slope (TS) were calculated from 24-hour Holter records. Left ventricular ejection fraction(LVEF)and were measured by Ultrasonic Cardiography. Three groups were diviled, ischemic heart disease, and hypertension with heart failure and dilated cardiomyopathy according to etiopathogenisis. CHF patients were classified into mild group (NYHAⅠ-Ⅱ级) and severe group(NYHAⅢ-Ⅳ级)according to NewYork Heart Association class; Patients were classified into the following HRT categories: HRT0 if both TO and TS were normal;HRT1 if either TO or TS was abnormal; HRT2 if both TO and TS were abnormal. Then patients were followed up 6-24 mouths. The primary end point was cardiac mortality or malignancy.According to the results,the patients were divided into the low-risk group and the high-risk group.Results CHF patients group showed significantly lower turbulence slopes and greater turbulence onset values compare with health group(P<0.05). The same trend is excist in severe and mild heart failure, which the heart rate turbulence more weaken even vanish in severe group(P<0.05). Both HRT parameters, especially turbulence slope, were significantly correlated with clinical indexes of CHF(P<0.05), were not correlated with etiopathogenisis of heart failure(P>0.05). Significant correlations were found betweenTS and the LVEF as well as with LV diameters.TS was significantly correlated with B-type natriuretic peptide (BNP) levels (r=-0.579, p<0.001 for turbulence slope).TS was associated with longer QRS duration, and progressively decreasing parameters of heart rate variability.There was no significant correlated with TO and TS. (r=-0.184, P>0.05).Abnormal HRT parameters were independent predictors of CHF severity measured by SDNN and LVEF <30%. There was significant difference in survival status among HRT0 group,HRT1 group and HRT2 group(all P<0.05).HRT2 was the strongest predictor and showed prognostic value to the primary end point in elderly patients with CHF(x2=5.9514, P =0.0147). Survival analysis indicated that TS and combination of TO and TS contributed to the end-point accident in patients with CHF. The combination of abnormal TO and abnormal TS (RR=2.894) was more powerful in multivate risk stratifier than LVEF(RR=0. 201) and others.Conclusion The findings indicate that in elderly patients with CHF, TS re?ects well the severity of CHF and is associated with LV dysfunction, SDNN, QRSD and BNP, but is not associated with etiopathogenisis of heart failure. It suggests that HRT is not only an index to decide the degree of CHF but also a new predictor of prognosis. HRT is a predictor better than other traditional factors.HRT may become a new and independent predictor of high-risk patients with CHF. HRT could be considered a well-accepted method for assessing risk stratifies in elderly patients with CHF.