%0 Journal Article %J J Cardiovasc Electrophysiol %D 2005 %T Sometimes higher heart rate variability is not better heart rate variability: results of graphical and nonlinear analyses. %A Stein, Phyllis K %A Domitrovich, Peter P %A Hui, Nelson %A Rautaharju, Pentti %A Gottdiener, John %K Aged %K Aged, 80 and over %K Algorithms %K Arrhythmia, Sinus %K Cohort Studies %K Diagnosis, Computer-Assisted %K Electrocardiography %K Female %K Heart Rate %K Humans %K Male %K Models, Cardiovascular %K Nonlinear Dynamics %K Numerical Analysis, Computer-Assisted %K Prevalence %K Proportional Hazards Models %K Reproducibility of Results %K Risk Assessment %K Risk Factors %K Sensitivity and Specificity %K United States %X

OBJECTIVE: To determine the prevalence and effect on traditional heart rate variability (HRV) indices of abnormal HRV patterns in the elderly.

METHODS: Hourly Poincaré plots and plots of spectral HRV from normal-to-normal interbeat intervals and hourly nonlinear HRV values were examined in a subset of 290 consecutive participants in the Cardiovascular Health Study. Only subjects in normal sinus rhythm with > or = 18 hours of usable data were included. Eligible subjects were 71 +/- 5 years. During 7 years of follow-up, 21.7% had died. Hours were scored as normal (0), borderline (0.5), or abnormal (1) from a combination of plot appearance and HRV. Summed scores were normalized to 100% to create an abnormality score (ABN). Short-term HRV versus each 5th percentile of ABN was plotted and a cutpoint for markedly increased HRV identified. The t-tests compared HRV for subjects above and below this cutpoint. Cox regression evaluated the association of ABN and mortality.

RESULTS: Of 5,815 eligible hourly plots, 64.4% were normal, 14.5% borderline, and 21.1% abnormal. HR, SDNN, SDNNIDX, ln VLF and LF power, and power law slope did not differ by the cutpoint for increased short-term HRV, while SDANN and ln ULF power were significantly lower for those above the cutpoint. However, many HRV indices including LF/HF ratio and normalized LF and HF power were significantly different between groups (P < 0.001). Increased ABN was significantly associated with mortality (P = 0.019). Despite similar values for many HRV indices, being in the group above the cutpoint was significantly associated with mortality (P = 0.04).

CONCLUSIONS: Abnormal HR patterns that elevate many HRV indices are prevalent among the elderly and associated with higher risk of mortality. Consideration of abnormal HRV may improve HRV-based risk stratification.

%B J Cardiovasc Electrophysiol %V 16 %P 954-9 %8 2005 Sep %G eng %N 9 %1 https://www.ncbi.nlm.nih.gov/pubmed/16174015?dopt=Abstract %R 10.1111/j.1540-8167.2005.40788.x