Complexity of Spontaneous QT Variability Unrelated to RR Variations and Respiration During Graded Orthostatic Challenge

Porta, Alberto; Cairo, Beatrice; Maria, Beatrice De; Bari, Vlasta

doi:10.22489/cinc.2020.009

Cited by 3 publications

(3 citation statements)

References 18 publications

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“…In addition to separate estimates of QT/RR hysteresis, i.e., corrections of the RR interval values to be used in QT/heartrate corrections, more complex autoregressive models involve both beat-to-beat RR interval history and QT interval history (Porta et al, 2010(Porta et al, , 2020El-Hamad et al, 2019). These approaches were shown useful in providing estimates of QT interval changes and variability that cannot be explained by heart rate and cardiac period influence (Baumert et al, 2016).…”

Section: Qt/rr Hysteresis Propertiesmentioning

confidence: 99%

Sex and Rate Change Differences in QT/RR Hysteresis in Healthy Subjects

et al. 2022

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While it is now well-understood that the extent of QT interval changes due to underlying heart rate differences (i.e., the QT/RR adaptation) needs to be distinguished from the speed with which the QT interval reacts to heart rate changes (i.e., the so-called QT/RR hysteresis), gaps still exist in the physiologic understanding of QT/RR hysteresis processes. This study was designed to address the questions of whether the speed of QT adaptation to heart rate changes is driven by time or by number of cardiac cycles; whether QT interval adaptation speed is the same when heart rate accelerates and decelerates; and whether the characteristics of QT/RR hysteresis are related to age and sex. The study evaluated 897,570 measurements of QT intervals together with their 5-min histories of preceding RR intervals, all recorded in 751 healthy volunteers (336 females) aged 34.3 ± 9.5 years. Three different QT/RR adaptation models were combined with exponential decay models that distinguished time-based and interval-based QT/RR hysteresis. In each subject and for each modelling combination, a best-fit combination of modelling parameters was obtained by seeking minimal regression residuals. The results showed that the response of QT/RR hysteresis appears to be driven by absolute time rather than by the number of cardiac cycles. The speed of QT/RR hysteresis was found decreasing with increasing age whilst the duration of individually rate corrected QTc interval was found increasing with increasing age. Contrary to the longer QTc intervals, QT/RR hysteresis speed was faster in females. QT/RR hysteresis differences between heart rate acceleration and deceleration were not found to be physiologically systematic (i.e., they differed among different healthy subjects), but on average, QT/RR hysteresis speed was found slower after heart rate acceleration than after rate deceleration.

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Section: Qt/rr Hysteresis Propertiesmentioning

confidence: 99%

Sex and Rate Change Differences in QT/RR Hysteresis in Healthy Subjects

et al. 2022

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“…Conversely, methods like heartbeat-evoked potentials have investigated the overall scalp activity response to the heartbeat, serving as an interoceptive measure ( Al et al, 2020 ). Moreover, specific research has delved into BHI representation in the multifractal domain ( Catrambone, Barbieri, Wendt, Abry, & Valenza, 2021 ), as well as the complexity of cerebrovascular joint dynamics ( Catrambone & Valenza, 2023a ; Porta, Cairo, De Maria, & Bari, 2020 ). Recent studies have also focused on detecting microstates (i.e., quasi-stable spatiotemporal states) of brain-heart axis dynamics ( Catrambone & Valenza, 2023b , 2023c ).…”

Section: Introductionmentioning

confidence: 99%

Impaired brain-heart axis in focal epilepsy: Alterations in information flow and implications for seizure dynamics

Frassineti,

Catrambone,

Lanatà

et al. 2024

Network Neuroscience

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This study delves into functional Brain-Heart Interplay (BHI) dynamics during interictal periods before and after seizure events in focal epilepsy. Our analysis focuses on elucidating the causal interaction between cortical and Autonomic Nervous System (ANS) oscillations, employing Electroencephalography and Heart Rate Variability series. The dataset for this investigation comprises 47 seizure events from 14 independent subjects, obtained from the publicly available Siena Dataset.Our findings reveal an impaired brain-heart axis especially in the Heart-to-Brain functional direction. This is particularly evident in bottom-up oscillations originating from sympathovagal activity during the transition between pre-ictal and post-ictal periods. These results indicates a pivotal role of the ANS in epilepsy dynamics. Notably, the Brain-to-Heart information flow targeting cardiac oscillations in the low-frequency band does not display significant changes. However, there are noteworthy changes in cortical oscillations, primarily originating in central regions, influencing heartbeat oscillations in the high-frequency band.Our study conceptualize seizures as a state of hyperexcitability and a network disease affecting both cortical and peripheral neural dynamics.Our results pave the way for a deeper understanding of BHI in epilepsy, which holds promise for the development of advanced diagnostic and therapeutic approaches also based on bodily neural activity for individuals living with epilepsy.

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“…QT interval variability without any correction for the RR variability has also been researched (Niemeijer et al, 2014;Baumert et al, 2016;van den Berg et al, 2019) including the reports of normal values in short-term ECG. While such studies might still have included data influenced by the underlying RR variability, physiologically important technical studies were also reported, investigating the QT interval variability with RR interval effects removed by regression modeling (Porta et al, 2010(Porta et al, , 2020El-Hamad et al, 2019). These studies have been based on shorter ECG recordings that allowed QT interval measurements on every beat basis.…”

Section: Introductionmentioning

confidence: 99%

Short-Term Beat-to-Beat QT Variability Appears Influenced More Strongly by Recording Quality Than by Beat-to-Beat RR Variability

et al. 2022

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Increases in beat-to-beat variability of electrocardiographic QT interval duration have repeatedly been associated with increased risk of cardiovascular events and complications. The measurements of QT variability are frequently normalized for the underlying RR interval variability. Such normalization supports the concept of the so-called immediate RR effect which relates each QT interval to the preceding RR interval. The validity of this concept was investigated in the present study together with the analysis of the influence of electrocardiographic morphological stability on QT variability measurements. The analyses involved QT and RR measurements in 6,114,562 individual beats of 642,708 separate 10-s ECG samples recorded in 523 healthy volunteers (259 females). Only beats with high morphology correlation (r > 0.99) with representative waveforms of the 10-s ECG samples were analyzed, assuring that only good quality recordings were included. In addition to these high correlations, SDs of the ECG signal difference between representative waveforms and individual beats expressed morphological instability and ECG noise. In the intra-subject analyses of both individual beats and of 10-s averages, QT interval variability was substantially more strongly related to the ECG noise than to the underlying RR variability. In approximately one-third of the analyzed ECG beats, the prolongation or shortening of the preceding RR interval was followed by the opposite change of the QT interval. In linear regression analyses, underlying RR variability within each 10-s ECG sample explained only 5.7 and 11.1% of QT interval variability in females and males, respectively. On the contrary, the underlying ECG noise contents of the 10-s samples explained 56.5 and 60.1% of the QT interval variability in females and males, respectively. The study concludes that the concept of stable and uniform immediate RR interval effect on the duration of subsequent QT interval duration is highly questionable. Even if only stable beat-to-beat measurements of QT interval are used, the QT interval variability is still substantially influenced by morphological variability and noise pollution of the source ECG recordings. Even when good quality recordings are used, noise contents of the electrocardiograms should be objectively examined in future studies of QT interval variability.

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Complexity of Spontaneous QT Variability Unrelated to RR Variations and Respiration During Graded Orthostatic Challenge

Cited by 3 publications

References 18 publications

Sex and Rate Change Differences in QT/RR Hysteresis in Healthy Subjects

Sex and Rate Change Differences in QT/RR Hysteresis in Healthy Subjects

Impaired brain-heart axis in focal epilepsy: Alterations in information flow and implications for seizure dynamics

Short-Term Beat-to-Beat QT Variability Appears Influenced More Strongly by Recording Quality Than by Beat-to-Beat RR Variability

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