Sometimes Higher Heart Rate Variability Is Not Better Heart Rate Variability: Results of Graphical and Nonlinear Analyses

Stein, Phyllis K.; Domitrovich, Peter P.; Hui, Nelson; Rautaharju, Pentti M.; Gottdiener, John S.

doi:10.1111/j.1540-8167.2005.40788.x

Cited by 193 publications

(168 citation statements)

References 22 publications

Supporting

Mentioning

158

Contrasting

Unclassified

Order By: Relevance

“…4 This means that the heart rate-to-HRV correlation is affected by SND, 2 and a higher HRV is not always a better HRV, which is sometimes associated with a higher risk of mortality. 25 Thus, the present results also indicate that abnormally higher HRV, compared with age-matched reference values, might suggest the presence of SND.…”

Section: Discussionsupporting

confidence: 62%

Breakdown of the Intermediate-Term Fractal Scaling Exponent in Sinus Node Dysfunction - New Method for Non-Invasive Evaluation of Sinus Node Function -

Shin

Lee

et al. 2011

Circ J

View full text Add to dashboard Cite

Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp inus node dysfunction (SND), also referred to as "sick sinus syndrome", is a common cause of cardiac syncope. 1 Sinus bradycardia (SB) is not only an incidental finding in otherwise healthy individuals, particularly in young adults, but also an electrocardiographic manifestation of SND. 2-5 Differentiation of so-called pathologic SB (due to intrinsic SND), from normal SB, is important in the diagnosis and management of SND.Heart rate variability (HRV) analysis, through classical linear methods, either in the time or the frequency domain, provides quantitative and non-invasive measures of the activity of the autonomic nervous system. 6,7 Information carried by the heart rate signal, however, may not be totally explained by this linear approach. 8-13 Non-linear dynamical system analysis based on the theories of fractal scaling and complexity have gained interest, because they may reveal information hidden in the regulatory system that cannot be detected using conventional methods. 14-20 Pathological states and aging are associated with distinctive alterations in these scaling properties, which could be of practical diagnostic and prognostic use. To date, the short-term scaling exponent (DFAα1) of detrended fluctuation analysis (DFA) has demonstrated greater clinical discrimination of various cardiac diseases.Most previous studies regarding heart rate dynamics and its interpretations were carried out in the presence of intact sinus node activity. We assumed that, if a dysfunctional sinus node does not respond appropriately to neuroautonomic input, then alteration or breakdown of the fractal scaling and complexity of heart rate dynamics would ensue. Little information exists concerning the non-linear behavior of sinus node pacemaker activity in SND. The purpose of the present study was to characterize the heart rate dynamics of SB in SND and to test Background: The aim of the present study was to characterize the heart rate dynamics of sinus bradycardia (SB) from sinus node dysfunction (SND) using non-linear dynamical system analysis. No data are yet available on how the dynamics change in the presence of SND.

show abstract

Section: Discussionsupporting

confidence: 62%

Breakdown of the Intermediate-Term Fractal Scaling Exponent in Sinus Node Dysfunction - New Method for Non-Invasive Evaluation of Sinus Node Function -

Shin

Lee

et al. 2011

Circ J

View full text Add to dashboard Cite

show abstract

“…These studies analyzed the shape of the Poincare plots and related it to pathology. For example, in healthy subjects the Poincare plot was found to be fan-shaped as a result of an increasing beat-to-beat R-R dispersion with increasing R-R interval duration (10,23), while in pathological subjects the shape is more complex (21). Quantitative analysis of the Poincare plots is based on indexes that are essentially correlated with the area occupied by the cloud of points in the plane (R-R(i),R-R(iϩ)) (10,23).…”

Section: Discussionmentioning

confidence: 99%

“…In the literature, several groups have dealt with the scatterplot in the plane (R-R(i),R-R(iϩ)) more commonly referred to as two-dimensional return map or Poincare plot [see e.g., 10,21,23]. These studies analyzed the shape of the Poincare plots and related it to pathology.…”

Section: Discussionmentioning

confidence: 99%

Temporal asymmetries of short-term heart period variability are linked to autonomic regulation

Porta

Casali

et al. 2008

American Journal of Physiology-Regulatory, Integrative and Comp

196

190

View full text Add to dashboard Cite

We exploit time reversibility analysis, checking the invariance of statistical features of a series after time reversal, to detect temporal asymmetries of short-term heart period variability series. Reversibility indexes were extracted from 22 healthy fetuses between 16th to 40th wk of gestation and from 17 healthy humans (aged 21 to 54, median ϭ 28) during graded head-up tilt with table inclination angles randomly selected inside the set {15, 30, 45, 60, 75, 90}. Irreversibility analysis showed that nonlinear dynamics observed in short-term heart period variability are mostly due to asymmetric patterns characterized by bradycardic runs shorter than tachycardic ones. These temporal asymmetries were 1) more likely over short temporal scales than over longer, dominant ones; 2) more frequent during the late period of pregnancy (from 25th to 40th week of gestation); 3) significantly present in healthy humans at rest in supine position; 4) more numerous during 75 and 90°head-up tilt. Results suggest that asymmetric patterns observable in short-term heart period variability might be the result of a fully developed autonomic regulation and that an important shift of the sympathovagal balance toward sympathetic predominance (and vagal withdrawal) can increase their presence. heart rate variability; autonomic nervous system; head-up tilt; fetal maturation; nonlinear dynamics THE VARIABILITY OF HEART PERIOD (usually approximated as the temporal distance between two consecutive R peaks on the ECG, R-R) has been proven to be nonlinear in healthy fetuses between 38th and 40th week of gestation (8) and in healthy humans (1, 4), mostly during experimental conditions periodically forcing cardiovascular regulation (i.e., controlled breathing) (15, 16). However, this finding has not been translated yet into a notion actually helpful in pathophysiology. The main reason is that, until now, the detection of nonlinear dynamics has not been linked to a clear temporal correlate (i.e., a pattern associated with nonlinear dynamics).Time irreversibility analysis checks the invariance of the statistical properties of a time series after time reversal. This analysis might be helpful to translate the involved concept of nonlinear dynamics into a simple, comprehensible notion useful in pathophysiology, since it clearly indicates a time domain scheme responsible for nonlinear dynamics. Indeed, time irreversibility analysis is capable of detecting a specific class of nonlinear dynamics, that is, those characterized by a temporal asymmetry. In other words, when a series is detected as irreversible using simple tests in the two-dimensional phase space (6, 9, 17), it can be stated that the nonlinear behavior is the result of the presence of asymmetric patterns (i.e., waveforms characterized by the upward side shorter or longer than the downward side), thus directly linking the abstract concept of nonlinear dynamics to a clear, easily imaginable, feature (17).The aim of this study is twofold. The first aim is to link the presence of temporal asymme...

show abstract

“…However, we have found that many older subjects and patients with cardiovascular disease have an increased beat-to-beat variability that is irregular and does not reflect underlying respiratory sinus arrhythmia (1). We have called this erratic rhythm.…”

mentioning

confidence: 99%

Development of more erratic heart rate patterns is associated with mortality post–myocardial infarction

Stein

Domitrovich

2008

Journal of Electrocardiology

Self Cite

View full text Add to dashboard Cite

Cardiac patients often have sinus arrhythmia of non-respiratory origin [erratic sinus rhythm" (ESR)]. ESR was quantified using hourly Poincaré and power spectral HRV plots from normal-to-normal interbeat intervals (N-Ns) and hourly values of the short-term fractal scaling exponent and correlations of N-Ns in N=60 non-survivors and N=66 randomly-selected survivors in the Cardiac Arrhythmia Suppression Trial. Hours were coded (ABN) as normal (0), borderline (0.5) or ESR (1). T-tests compared ABN for N=2413 paired hours at baseline and on therapy. ABN was higher in nonsurvivors (0.38 ± 0.44 vs. 0.28 ± 0.40, baseline and 0.51 ± 0.45 vs. 0.34 ± 0.43, on therapy, p<0.001). Increased ABN with treatment was greater in non-survivors. Normal hours at baseline (RR=0.77, 095% CI=0.62−0.96, p=0.018) and on treatment (RR=0.47, 95%CI=0.39−0.58) were significantly associated with decreased mortality compared to ESR. Quantification of ESR may identify more vulnerable patients or help monitor the effects of pharmacological treatment. Keywordsheart rate; risk factor; mortality; post-MI; anti-arrhythmic The analysis of heart rate variability (HRV) provides information about cardiac autonomic function. However, we have found that many older subjects and patients with cardiovascular disease have an increased beat-to-beat variability that is irregular and does not reflect underlying respiratory sinus arrhythmia (1). We have called this erratic rhythm. The presence of erratic rhythm, which is frequently episodic, increases values for short-term HRV indices such as rMSSD [root mean square of successive differences of normal-to-normal (N-N) interbeat intervals in ms], pNN50 [the % of N-N intervals >50 ms different from the previous interval) and high frequency power (the amount of variance in N-N intervals at respiratory frequencies, i.e., 0.15−0.4 Hz) that quantify beat-to-beat variability. Thus, in the presence of erratic rhythm, increased short-term HRV does not, as it does for younger people, necessarily reflect greater parasympathetic control of heart rate. A high prevalence of erratic rhythm may also explain why HRV measures that are believed to reflect parasympathetic function have relatively little predictive value for outcomes. At the same time, some "non-linear" HRV measures like the short-term fractal scaling exponent, (DFA1), and (SD12), the ratio of the axes of an ellipse fitted to the Poincaré plot do capture the presence of erratic rhythm (2,3).

show abstract

Sometimes Higher Heart Rate Variability Is Not Better Heart Rate Variability: Results of Graphical and Nonlinear Analyses

Abstract: 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.

Cited by 193 publications

References 22 publications

Breakdown of the Intermediate-Term Fractal Scaling Exponent in Sinus Node Dysfunction - New Method for Non-Invasive Evaluation of Sinus Node Function -

Breakdown of the Intermediate-Term Fractal Scaling Exponent in Sinus Node Dysfunction - New Method for Non-Invasive Evaluation of Sinus Node Function -

Temporal asymmetries of short-term heart period variability are linked to autonomic regulation

Development of more erratic heart rate patterns is associated with mortality post–myocardial infarction

Contact Info

Product

Resources

About