Deviation Of Average NN Intervals Research Articles

Nomogram Model Based on Clinical Risk Factors and Heart Rate Variability for Predicting All-Cause Mortality in Stage 5 CKD Patients.

Background: Heart rate variability (HRV), reflecting circadian rhythm of heart rate, is reported to be associated with clinical outcomes in stage 5 chronic kidney disease (CKD5) patients. Whether CKD related factors combined with HRV can improve the predictive ability for their death remains uncertain. Here we evaluated the prognosis value of nomogram model based on HRV and clinical risk factors for all-cause mortality in CKD5 patients. Methods: CKD5 patients were enrolled from multicenter between 2011 and 2019 in China. HRV parameters based on 24-h Holter and clinical risk factors associated with all-cause mortality were analyzed by multivariate Cox regression. The relationships between HRV and all-cause mortality were displayed by restricted cubic spline graphs. The predictive ability of nomogram model based on clinical risk factors and HRV were evaluated for survival rate. Results: CKD5 patients included survival subgroup (n = 155) and all-cause mortality subgroup (n = 45), with the median follow-up time of 48 months. Logarithm of standard deviation of all sinus R-R intervals (lnSDNN) (4.40 ± 0.39 vs. 4.32 ± 0.42; p = 0.007) and logarithm of standard deviation of average NN intervals for each 5 min (lnSDANN) (4.27 ± 0.41 vs. 4.17 ± 0.41; p = 0.008) were significantly higher in survival subgroup than all-cause mortality subgroup. On the basis of multivariate Cox regression analysis, the lnSDNN (HR = 0.35, 95%CI: 0.17–0.73, p = 0.01) and lnSDANN (HR = 0.36, 95% CI: 0.17–0.77, p = 0.01) were associated with all-cause mortality, their relationships were negative linear. Spearman’s correlation analysis showed that lnSDNN and lnSDANN were highly correlated, so we chose lnSDNN, sex, age, BMI, diabetic mellitus (DM), β-receptor blocker, blood glucose, phosphorus and ln intact parathyroid hormone (iPTH) levels to build the nomogram model. The area under the curve (AUC) values based on lnSDNN nomogram model for predicting 3-year and 5-year survival rates were 79.44% and 81.27%, respectively. Conclusion: In CKD5 patients decreased SDNN and SDANN measured by HRV were related with their all-cause mortality, meanwhile, SDNN and SDANN were highly correlated. Nomogram model integrated SDNN and clinical risk factors are promising for evaluating their prognosis.

MO501: A Nomogram Based on Heart Rate Variability Parameters for Predicting All-Cause Mortality in Stage 5 CKD Patients

Abstract BACKGROUND AND AIMS Heart rate variability (HRV), reflecting the circadian rhythm of heart rate, is associated with clinical outcomes in stage 5 chronic kidney disease 5 (CKD5) patients. Whether CKD-related factors combined with HRV can improve the predictive ability for their death remains uncertain. Here we evaluated the prognosis value of nomogram models based on HRV for all-cause mortality in CKD5 patients. METHOD Multicenter CKD5 patients were enrolled from 2011 to 2019 in China. The multivariate Cox regression analysis screened HRV parameters, which associated with all-cause mortality. Their relationships were displayed by restricted cubic spline graphs. The predictive abilities of nomogram models were evaluated for survival rate. RESULTS CKD5 patients included survival group (n = 155) and the all-cause mortality group (n = 45), with a median follow-up time of 48 months. Logarithm of standard deviation of all sinus R–R intervals (lnSDNN) {HR: 0.35, [95% confidence interval (95% CI): 0.17–0.73]; P = .01} and logarithm of standard deviation of average NN intervals for each 5 min (lnSDANN) (HR: 0.36, 95% CI: 0.17–0.77; P = .01) were associated with all-cause mortality, their relationships were negative linear. The area under the curve (AUC) values based on lnSDNN nomogram model for predicting 3-year and 5-year survival rates were 79.44% and 81.27%, respectively. The AUC values based on lnSDANN nomogram model for predicting 3-year and 5-year survival rates were 78.73% and 80.61%, respectively. CONCLUSION As clinical indicators of heart rate circadian rhythm, SDNN and SDANN are highly correlated with the prognosis of CKD5 patients. Nomogram models that integrate HRV and multiple CKD-related risk factors are promising for evaluating their all-cause mortality.

Gender-specific response to acute mental stress assessed by heart rate variability

Background: Long-standing stress is an important risk factor for many diseases. Certain diseases are found to be associated with males than females. This difference may be due to the variation in the reactivity to stress exhibited by both the sexes which we assessed in the present study. The responses during stress are mediated partly by sympathetic and parasympathetic branches of autonomic nervous system (ANS). Heart rate variability (HRV) is a simple and non-invasive tool to study ANS. HRV can be analyzed by time domain and frequencydomain methods. The HRV in males and females during mental stress test may point to their disparity in autonomic response to stress and hence the predisposition to various diseases. Aim and Objective: The objective of this study was to assess the autonomic activity in males and females at rest and during mental stress test using HRV. Materials and Methods: There were 12 males and 18 females in the study who were selected based on inclusion and exclusion criteria. Mental arithmetic test is used to induce mental stress. HRV was calculated during baseline condition and mental stress test. Square root of the mean squared differences of successive NN intervals (RMSSD) and standard deviation of average NN intervals are the variables used in time domain analysis of HRV. Low-frequency (LF), high-frequency (HF), and LF/HF were used under frequency domain analysis. Results: There was a statistically significant difference in RMSSD during mental stress test. None of the other variables did not show any difference between two groups at rest and also during mental stress test. Conclusion: Less HRV in males during mental stress test indicates a shift of autonomic balance toward sympathetic activity in them. This shows that they are more predisposed to complications associated with stress.

Nonreassuring fetal heart rate decreases heart rate variability in newborn infants.

Nonreassuring fetal status (NRFS) refers to a compromised fetal condition which implies hypoxia. The influence of intrapartum hypoxia on autonomic nervous system function in early postnatal life is unknown. This study explored the influence of NRFS on the heart rate variability (HRV) of newborn infants. Singleton newborn infants delivered through Cesarean delivery (CD) with indications of elective purpose (n = 32), dystocia (n = 29), or NRFS (n = 22), and through vaginal birth (VB) (n = 80) were consecutively collected. HRV parameters including standard deviation of average NN intervals (SDANN), low frequency (LF), high frequency (HF), LF%, HF%, and total power (TP), were obtained for analysis in 3 days postpartum. An independent t-test or one-way ANOVA was used to compare differences in numeric data. SDANN, HF, HF%, and TP of newborn infants in the VB group were significantly higher than those in the CD group. The NRFS group had significantly lower SDANN, HF, and TP than those of the elective group, and significantly lower HF, HF%, and TP than those of the dystocia group. Newborn infants delivered through Cesarean section had lower HRV, especially those who experienced NRFS during labor. The long-term effects of changes of HRV in neonates require further evaluation.

Effect of 21 mg transdermal nicotine patches and smoking cessation on heart rate variability

The effect of smoking cessation on cardiac autonomic tone, as reflected by indexes of heart rate variability (HRV), has not been reported. Current smokers (n = 54, mean ± SD age 43 ± 12 years) who desired to quit, and were smoking ≥1 pack/day and had made ≥1 prior attempt at quitting, had 24-hour electrocardiographic recordings. They then attended smoking cessation classes and used transdermal nicotine patches while abstaining from smoking. After 4 to 6 weeks of using 21 mg patches, the 24-hour electrocardiogram was repeated (n = 35). Four weeks after cessation of patch use, the 24-hour electrocardiogram was again recorded in subjects who continued to be abstinent (n = 25). Time and frequency domain measures of HRV based on normal R to R (NN) intervals were computed for all recordings. Smoking cessation significantly decreased heart rate, and increased all 24-hour time and frequency domain indexes of HRV. Part of this change occurred in the transition from smoking to the patch, and further changes occurred with cessation of patch use. For example, the standard deviation of average NN intervals was 114 ± 28 ms at baseline, 121 ± 41 ms with the patch, and 135 ± 26 ms after quitting. At 4 weeks after cessation of all nicotine use, the average heart rate remained higher, and HRV remained lower than values reported for healthy, middle-aged adults.