Influence of age, the autonomic nervous system and anxiety on QT-interval variability

2001 ◽  
Vol 101 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Gianfranco PICCIRILLO ◽  
Mauro CACCIAFESTA ◽  
Marco LIONETTI ◽  
Marialuce NOCCO ◽  
Vincenza DI GIUSEPPE ◽  
...  
Keyword(s):  
Heart Rate ◽  
Qt Interval ◽  
Spectral Power ◽  
Low Frequency ◽  
Elderly Subjects ◽  
Rr Interval ◽  
T Wave ◽  
Qt Variability ◽  
Qt Interval Variability ◽  
Sympathetic Stress

As QT variability increases and heart rate variability diminishes, the QT variability index (QTVI)-a non-invasive measure of beat-to-beat fluctuations in QT interval on a single ECG lead-shows a trend towards positive values. Increased QT variability is a risk factor for sudden death. Aging lengthens the QT interval and reduces RR-interval variability. In the present study we investigated the influence of aging and the autonomic nervous system on QT-interval variability in healthy subjects. We studied 143healthy subjects, and divided them into two age ranges (younger and older than 65 years). For each subject we measured two QTVIs: from the q wave to the end of the T wave (QTeVI) and to the apex of the T wave (QTaVI). Both indexes were calculated at baseline and after sympathetic stress. In 10 non-elderly subjects, both QTVIs were determined after β-adrenoreceptor blockade induced by intravenous infusion of propranolol or sotalol. The QTVI was higher in elderly than in younger subjects (P < 0.001). QTVIs obtained during sympathetic stress remained unchanged in the elderly, but became more negative in the younger group (P < 0.05). QTeVI and QTaVI at baseline were correlated positively with age (P < 0.01) and anxiety scores (P < 0.05), but inversely with the low-frequency spectral power of RR-interval variability (P < 0.001). QTVIs were higher in subjects with higher anxiety scores. In younger subjects, sotalol infusion increased both QTVIs significantly, whereas propranolol infusion did not. In conclusion, aging increases QT-interval variability. Whether this change is associated with an increased risk of sudden death remains unclear. The association of abnormal QT-interval variability with anxiety and with reduced low-frequency spectral power of heart rate variability merits specific investigation. In healthy non-elderly subjects, acute sympathetic stress (tilt) decreases the QTVI. β-Adrenoreceptor blockade inhibits this negative trend, thus showing its sympathetic origin. Because a negative trend in QTVI induced by sympathetic stress increases only in younger subjects, it could represent a protective mechanism that is lost with aging.

IDENTIFYING THE CORRELATION BETWEEN ENCEPHALOGRAPHIC SIGNAL IRREGULARITY AND HEART RATE VARIABILITY TO DIFFERENTIATE INTERNALLY AND EXTERNALLY OPERATIVE ATTENTION

2020 ◽  
Vol 32 (02) ◽  
pp. 2050014
Author(s):  
M. Kumar ◽  
D. Singh ◽  
K. K. Deepak
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Negative Correlation ◽  
Spectral Power ◽  
Low Frequency ◽  
Significant Negative Correlation ◽  
Eeg Signal ◽  
Rr Interval ◽  
Attention Tasks ◽  
Significant Difference

This study identifies a correlation between low-frequency heart rate variability (LF-HRV) and encephalographic (EEG) complexity to differentiate internally operative attention (INT) and externally operative attention (EXT). Electrophysiological fluctuations in response to Posner’s spatial orienting paradigm were explored in 14 healthy volunteers who participated in 6 alternating sessions of attention tasks. HRV analysis was used to measure heart rate fluctuations, and approximate entropy (ApEn) was used to measure changes in the irregularity of EEG and HRV. Power spectral analysis of HRV revealed that there was found to be a significant difference between INT and EXT for HRV-low frequency (HRV-LF) and LH/HF ratio. ApEn for RR-interval time series increased for both attention tasks as compared to baseline and recovery session. The relationship between HRV-LF and EEG spectral power measured at F4 revealed significant negative correlation during ([Formula: see text], with [Formula: see text]) EXT than ([Formula: see text], with [Formula: see text]) INT. Furthermore, a significant positive correlation, yet of moderate strength was noted between HRV-LF and ApEn of EEG signal measured at POz ([Formula: see text], with [Formula: see text]) during EXT as compared to INT ([Formula: see text], with [Formula: see text]) and, a significant negative correlation was observed between ApEn of RR-interval and ApEn of EEG signal measured at POz ([Formula: see text], with [Formula: see text]) during EXT as compared to INT ([Formula: see text], with [Formula: see text]). Thus, it is evident that EXT leads to more irregularity in parietal regions of the brain than the INT. During EXT, the irregularity over the parietal region linked to increased sympathetic activity as compared to INT and corresponds to decreased heart rate. These results may benefit in designing robust human-computer interfaces and accelerated training paradigm to raise an athlete’s performance.

Very-low-frequency oscillations in heart rate and blood pressure in periodic breathing: role of the cardiovascular limb of the hypoxic chemoreflex

2000 ◽  
Vol 99 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Darrel P. FRANCIS ◽  
L. Ceri DAVIES ◽  
Keith WILLSON ◽  
Piotr PONIKOWSKI ◽  
Andrew J. S. COATS ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Heart Rate ◽  
Chronic Heart Failure ◽  
Spectral Power ◽  
Low Frequency ◽  
Periodic Breathing ◽  
Free Breathing ◽  
Very Low Frequency ◽  
Rr Interval

In chronic heart failure, very-low-frequency (VLF) oscillations (0.01–0.04 Hz) in heart rate and blood pressure may be related to periodic breathing, although the mechanism has not been fully characterized. Groups of ten patients with chronic heart failure and ten healthy controls performed voluntary periodic breathing with computer guidance, while ventilation, oxygen saturation, non-invasive blood pressure and RR interval were measured. In air, voluntary periodic breathing induced periodic desaturation and prominent VLF oscillations when compared with free breathing in both patients [RR interval spectral power from 179 to 358 ms2 (P < 0.05); systolic blood pressure (SBP) spectral power from 3.44 to 6.25 mmHg2 (P < 0.05)] and controls [RR spectral power from 1040 to 2307 ms2 (P < 0.05); SBP spectral power from 3.40 to 9.38 mmHg2 (P < 0.05)]. The peak in RR interval occurred 16–26 s before that in SBP, an anti-baroreflex pattern. When the patients followed an identical breathing pattern in hyperoxic conditions to prevent desaturation, the VLF RR interval spectral power was 50% lower (179.0±51.7 ms2; P < 0.01) and the VLF SBP spectral power was 44% lower (3.51±0.77 mmHg2; P < 0.01); similar effects were seen in controls (VLF RR power 20% lower, at 1847±899 ms2, P < 0.05; VLF SBP power 61% lower, at 3.68±0.92 mmHg2, P = 0.01). Low- and high-frequency spectral powers were not significantly affected. Thus periodic breathing causes oxygen-sensitive (and by implication chemoreflex-related) anti-baroreflex VLF oscillations in RR interval and blood pressure in both patients with chronic heart failure and normal controls.

scholarly journals Blood pressure regulation in diabetic patients with and without peripheral neuropathy

2012 ◽  
Vol 302 (5) ◽  
pp. R541-R550 ◽  
Author(s):  
Siqi Wang ◽  
David C. Randall ◽  
Charles F. Knapp ◽  
Abhijit R. Patwardhan ◽  
Kevin R. Nelson ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Peripheral Neuropathy ◽  
Spectral Power ◽  
Low Frequency ◽  
Diabetic Patients ◽  
Motor Neuropathy ◽  
Sympathetic Control ◽  
Rr Interval ◽  
Low Frequency Power

Cardiac and vascular dysfunctions resulting from autonomic neuropathy (AN) are complications of diabetes, often undiagnosed. Our objectives were to: 1) determine sympathetic and parasympathetic components of compromised blood pressure (BP) regulation in patients with peripheral neuropathy and 2) rank noninvasive indexes for their sensitivity in diagnosing AN. We continuously measured electrocardiogram, arterial BP, and respiration during supine rest and 70° head-up tilt in 12 able-bodied subjects, 7 diabetics without, 7 diabetics with possible, and 8 diabetics with definite, sensory, and/or motor neuropathy (D2). During the first 3 min of tilt, systolic BP (SBP) of D2 decreased [−10.9 ± 4.5 (SE) mmHg] but increased in able-bodied (+4.8 ± 5.4 mmHg). Compared with able-bodied, D2 had smaller low-frequency (0.04–0.15 Hz) spectral power of diastolic BP, lower baroreflex effectiveness index (BEI), and more SBP ramps. Except for low-frequency power of SBP, D2 had greater SBP and smaller RR interval harmonic and nonharmonic components at rest across the 0.003- to 0.45-Hz region. In addition, our results support previous findings of smaller HF RR interval power, smaller numbers of baroreflex sequences, and lower baroreflex sensitivity in D2. We conclude that diabetic peripheral neuropathy is accompanied by diminished parasympathetic and sympathetic control of heart rate and peripheral vasomotion and diminished baroreflex regulation. A novel finding of this study lies in the sensitivity of BEI to detect AN, presumably because of its combination of parameters that measure reductions in both sympathetic control of vasomotion and parasympathetic control of heart rate.

Relationship of QT interval variability to heart rate and RR interval variability

2013 ◽  
Vol 46 (6) ◽  
pp. 591-596 ◽  
Author(s):  
Katerina Hnatkova ◽  
Donna Kowalski ◽  
James J. Keirns ◽  
E. Marcel van Gelderen ◽  
Marek Malik
Keyword(s):  
Heart Rate ◽  
Qt Interval ◽  
Rr Interval ◽  
Relationship Of ◽  
Qt Interval Variability

scholarly journals Heart Rate Influence on the QT Variability Risk Factors

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1096
Author(s):  
Irena Andršová ◽  
Katerina Hnatkova ◽  
Martina Šišáková ◽  
Ondřej Toman ◽  
Peter Smetana ◽  
...  
Keyword(s):  
Heart Rate ◽  
Standard Deviation ◽  
Qt Interval ◽  
Healthy Subjects ◽  
Sequential Analysis ◽  
Rr Intervals ◽  
Qt Variability Index ◽  
Qt Variability ◽  
Variability Index ◽  
Qt Interval Variability

QT interval variability, mostly expressed by QT variability index (QTVi), has repeatedly been used in risk diagnostics. Physiologic correlates of QT variability expressions have been little researched especially when measured in short 10-second electrocardiograms (ECGs). This study investigated different QT variability indices, including QTVi and the standard deviation of QT interval durations (SDQT) in 657,287 10-second ECGs recorded in 523 healthy subjects (259 females). The indices were related to the underlying heart rate and to the 10-second standard deviation of RR intervals (SDRR). The analyses showed that both QTVi and SDQT (as well as other QT variability indices) were highly statistically significantly (p < 0.00001) influenced by heart rate and that QTVi showed poor intra-subject reproducibility (coefficient of variance approaching 200%). Furthermore, sequential analysis of regression variance showed that SDQT was more strongly related to the underlying heart rate than to SDRR, and that QTVi was influenced by the underlying heart rate and SDRR more strongly than by SDQT (p < 0.00001 for these comparisons of regression dependency). The study concludes that instead of QTVi, simpler expressions of QT interval variability, such as SDQT, appear preferable for future applications especially if multivariable combination with the underlying heart rate is used.

Characteristics of heart rate variability in patients with acute coronary syndrome without ST segment elevation in comparison with clinical and biochemical parameters

2021 ◽  
Vol 29 (3) ◽  
pp. 369-378
Author(s):  
Aleksej A. Nizov ◽  
Aleksej I. Girivenko ◽  
Mihail M. Lapkin ◽  
Aleksej V. Borozdin ◽  
Yana A. Belenikina ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Acute Coronary Syndrome ◽  
Creatine Phosphokinase ◽  
Spectral Power ◽  
Low Frequency ◽  
Heart Rhythm ◽  
St Segment Elevation ◽  
Coronary Syndrome ◽  
St Segment

BACKGROUND: The search for rational methods of primary, secondary, and tertiary prevention of coronary heart disease. To date, there are several publications on heart rate variability in ischemic heart disease. AIM: To study the state of the regulatory systems in the organism of patients with acute coronary syndrome without ST segment elevation based on the heart rhythm, and their relationship with the clinical, biochemical and instrumental parameters of the disease. MATERIALS AND METHODS: The open comparative study included 76 patients (62 men, 14 women) of mean age, 61.0 0.9 years, who were admitted to the Emergency Cardiology Department diagnosed of acute coronary syndrome without ST segment elevation. On admission, cardiointervalometry was performed using Varicard 2.51 apparatus, and a number of clinical and biochemical parameters were evaluated RESULTS: Multiple correlations of parameters of heart rate variability and clinical, biochemical and instrumental parameters were observed. From this, a cluster analysis of cardiointervalometry was performed, thereby stratifying patients into five clusters. Two extreme variants of dysregulation of the heart rhythm correlated with instrumental and laboratory parameters. A marked increase in the activity of the subcortical nerve centers (maximal increase of the spectral power in the very low frequency range with the underlying reduction of SDNN) in cluster 1 was associated with reduction of the left ventricular ejection fraction: cluster 147.0 [40.0; 49.0], cluster 260.0 [58.0; 64.0], cluster 360.0 [52.5; 64.5] % (the data are presented in the form of median and interquartile range; Me [Q25; Q75], p 0,05). Cluster 5 showed significant reduction in SDNN (monotonous rhythm), combined with increased level of creatine phosphokinase (CPC): cluster 5446,0 [186.0; 782.0], cluster 4141.0 [98.0; 204.0] IU/l; Me [Q25; Q75], p 0.05) and MВ-fraction of creatine phosphokinase; cluster 532.0 [15.0; 45.0], 4 cluster 412.0 [9.0; 18.0] IU/l; Me [Q25; Q75], p 0.05). CONCLUSIONS: In patients with acute coronary syndrome without ST segment elevation, cluster analysis of parameters of heart rate variability identified different peculiarities of regulation of the heart rhythm. Pronounced strain of the regulatory systems of the body was found to be associated with signs of severe pathology: the predominance of VLF (spectral power of the curve enveloping a dynamic range of cardiointervals in the very low frequency range) in spectral analysis with an underlying reduced SDNN is characteristic of patients with a reduced ejection fraction, and a monotonous rhythm is characteristic of patients with an increased level of creatine phosphokinase and MB-fraction of creatine phosphokinase.

scholarly journals Analysis of heart rate variability in corn snakes (Pantherophis guttatus)

2021 ◽  
Vol 10 (11) ◽  
pp. e294101119781
Author(s):  
Antonio Gomes da Silva Neto ◽  
Daniel Souza Ferreira Magalhães ◽  
Raduan Hage ◽  
Laurita dos Santos ◽  
José Carlos Cogo
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Low Frequency ◽  
Autonomic Nervous ◽  
Rr Interval ◽  
Diagnosis And Prognosis ◽  
Frequency Domains ◽  
The Time Domain

The assessment of heart rate variability (HRV) by linear methods in conjunction with Poincaré plots can be useful for evaluating cardiac regulation by the autonomic nervous system and for the diagnosis and prognosis of heart disease in snakes. In this report, we describe an analysis of HRV in conscious adult corn snakes Pantherophis guttatus (P. guttatus).  The electrocardiogram (ECG) parameters were determined in adult corn snakes (8 females, 13 males) and used for HRV analysis, and the RR interval was analyzed by linear methods in the time and frequency domains. There was no sex-related difference in heart rate. However, significant differences were seen in the duration of the P, PR, and T waves and QRS complex; there was no difference in the QT interval. The values for the RR interval varied by 15.3% and 18.8% in male and female snakes, respectively, and there was considerable variation in the values for the high and low frequency domains. The changes in the time domain were attributed to regulation by the parasympathetic branch of the autonomic nervous system, in agreement with variations in the high and low frequency domains. The values for standard deviations 1 and 2 in Poincaré plots, as well as the values of the frequency domain, provide useful parameters for future studies of cardiac function in P. guttatus.

scholarly journals Association between physical performance and electrocardiographic heart rate corrected-QT interval in elderly subjects

2013 ◽  
Vol 62 (4) ◽  
pp. 283-291 ◽  
Author(s):  
Ryoma Michishita ◽  
Chika Fukae ◽  
Rikako Mihara ◽  
Masahiro Ikenaga ◽  
Kazuhiro Morimura ◽  
...  
Keyword(s):  
Heart Rate ◽  
Physical Performance ◽  
Qt Interval ◽  
Elderly Subjects ◽  
Corrected Qt Interval

scholarly journals Cardiomyocyte Deletion of Bmal1 Exacerbates QT- and RR-Interval Prolongation in Scn5a+/ΔKPQ Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Elizabeth A. Schroder ◽  
Jennifer L. Wayland ◽  
Kaitlyn M. Samuels ◽  
Syed F. Shah ◽  
Don E. Burgess ◽  
...  
Keyword(s):  
Heart Rate ◽  
Circadian Clock ◽  
Qt Interval ◽  
Adult Mouse ◽  
Interval Prolongation ◽  
Rr Interval ◽  
Adult Cardiomyocytes ◽  
Channel Expression ◽  
Cell Type Specific

Circadian rhythms are generated by cell autonomous circadian clocks that perform a ubiquitous cellular time-keeping function and cell type-specific functions important for normal physiology. Studies show inducing the deletion of the core circadian clock transcription factor Bmal1 in adult mouse cardiomyocytes disrupts cardiac circadian clock function, cardiac ion channel expression, slows heart rate, and prolongs the QT-interval at slow heart rates. This study determined how inducing the deletion of Bmal1 in adult cardiomyocytes impacted the in vivo electrophysiological phenotype of a knock-in mouse model for the arrhythmogenic long QT syndrome (Scn5a+/ΔKPQ). Electrocardiographic telemetry showed inducing the deletion of Bmal1 in the cardiomyocytes of mice with or without the ΔKPQ-Scn5a mutation increased the QT-interval at RR-intervals that were ≥130 ms. Inducing the deletion of Bmal1 in the cardiomyocytes of mice with or without the ΔKPQ-Scn5a mutation also increased the day/night rhythm-adjusted mean in the RR-interval, but it did not change the period, phase or amplitude. Compared to mice without the ΔKPQ-Scn5a mutation, mice with the ΔKPQ-Scn5a mutation had reduced heart rate variability (HRV) during the peak of the day/night rhythm in the RR-interval. Inducing the deletion of Bmal1 in cardiomyocytes did not affect HRV in mice without the ΔKPQ-Scn5a mutation, but it did increase HRV in mice with the ΔKPQ-Scn5a mutation. The data demonstrate that deleting Bmal1 in cardiomyocytes exacerbates QT- and RR-interval prolongation in mice with the ΔKPQ-Scn5a mutation.

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