Heart rate variability: Highlights from hidden signals

Yılmaz, Mücahid; Kayançiçek, Hidayet; Çekici, Yusuf

doi:10.15761/jic.1000258

Cited by 22 publications

(15 citation statements)

References 43 publications

(65 reference statements)

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“…Our findings suggested there is evidence of reduced parasympathetic system activity in epileptic patients which was consistent with the previous studies by Mukherjee et al, 21 Lotufo et al, 23 and Yilmaz et al 17 …”

Section: Discussionsupporting

confidence: 93%

“…The following time domain parameters were measured: 17 Mean RR (ms): the mean of the RR interval. pNN50 (%): the percentage of differences greater than 50 ms between successive normal RR intervals in a 24-hour ECG record.…”

Section: Methodsmentioning

confidence: 99%

“…The following frequency domain parameters were measured: 17 LF (ms 2 ): it includes the absolute power of low-frequency band range between 0.04 Hz and 0.15 Hz and consists of a combination of sympathetic and parasympathetic effects. HF (ms 2 ): it includes the absolute power of high-frequency band range between 0.16 Hz and 0.4 Hz.…”

Section: Methodsmentioning

confidence: 99%

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Evaluation of Heart Rate Variability Parameters During Awake and Sleep in Refractory and Controlled Epileptic Patients

Hamdy¹,

Abdel-Tawab²,

Elaziz³

et al. 2022

IJGM

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Background Alterations of heart rate variability (HRV) in epileptic patients were the field of interest of several studies for many reasons, particularly the contribution toward sudden unexpected death in epilepsy (SUDEP). Aim We aimed at evaluation of autonomic dysfunction in epileptic patients during awake and sleep in addition to studying the association between SUDEP risk with different Holter parameters. Patients and Methods The study included eighty epileptic patients (40 controlled epileptic patients and 40 refractory epileptic patients) compared to 30 volunteers as control group. They underwent detailed epileptic history, Chalfont seizure severity scale, sudden unexpected death in epilepsy (SUDEP)-7 risk score and 24 hour Holter monitoring to assess HRV parameters. Results Patients with refractory epilepsy had longer duration of epilepsy with increased number of used AEDs compared to controlled epileptic group. Both controlled and refractory epileptic patients had significantly higher average heart rate (AV.HR), sympatho-vagal ratio (low-frequency/high-frequency (LF/HF) ratio in 24 hours, daytime, and nighttime), and LF and HF values compared to controls. The rMSSD (the root mean square of difference between successive normal intervals), Tri.Index (triangular index), and pNN50 (percentage of the number of pairs of consecutive beat-to-beat intervals that varied by 50 ms) were significantly reduced in both epileptic groups compared to controls. Among refractory epileptic patients, patients with generalized epilepsy had significantly higher severity epileptic scale, average heart rate, minimum heart rate, and LF/HF night, in addition to lower rMSSD and pNN50 compared to patients with focal epilepsy. We found positive correlation between the following Holter indices (LF/HF 24, LF/HF day, and LF/HF night) and the duration of the epilepsy, while negative correlations between Tri.Index, LF, and HF and the epileptic duration were detected. SUDEP-7 risk was negatively correlated with pNN50 and rMSSD; meanwhile, it was positively correlated with LF/HF 24. The severity of epilepsy among refractory epileptic patients was positively correlated with average heart rate but negatively correlated with pNN50 and rMSSD. Using linear regression analysis, we found that pNN50 and rMSSD could predict SUDEP-7 risk and severity of epilepsy in refractory epileptic patients. Conclusion Epileptic patients (particularly refractory patients with generalized EEG findings and long duration) had reduced heart rate variability and hence impairment of parasympathetic activity with increased susceptibility for adverse outcomes. Moreover, pNN50 and rMSSD could be used as predictors for SUDEP-7 risk as well as severity of epilepsy in refractory epileptic patients.

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Section: Discussionsupporting

confidence: 93%

Section: Methodsmentioning

confidence: 99%

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Evaluation of Heart Rate Variability Parameters During Awake and Sleep in Refractory and Controlled Epileptic Patients

Hamdy¹,

Abdel-Tawab²,

Elaziz³

et al. 2022

IJGM

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“…The time-domain and nonlinear measurements of HRV were conducted to evaluate the health condition of the volunteer in 24 h. The average value of the R-R intervals (AVRR) is 728.17 ms, showing that the average heart rate of the volunteer is 82 bpm, which is in the normal heart rate range (60-100 bpm). The standard deviation of the R-R intervals (SDRR) is 162.31 ms and the root mean square of successive differences is 43.38 ms, indicating that the parasympathetic nerves had strong activities within the 24 h. [78] The R-R interval histogram, which represents the overall situation of heart rate changes, shows that R-R intervals are mainly distributed in the range of 400-1000 ms, with the main peak at around 550 ms (Figure 5i). The HRV triangular index (HRVI) that is determined by dividing the number of total R-R intervals by the number of most frequently observed R-R intervals is 44.90, suggesting that the volunteer is in healthy conditions (22 < HRVI < 52).…”

Section: Resultsmentioning

confidence: 99%

A Flexible and Stretchable 12‐Lead Electrocardiogram System with Individually Deformable Interconnects

Wan

Gao

Shang

et al. 2021

Adv Materials Technologies

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Holters may accommodate the demand of daily health monitoring of hearts. [14][15][16] But current ECG monitoring systems either contain small numbers of leads that are used as consumer electronics for diagnosing limited numbers of symptoms [17][18][19][20] or contains multiple rigid leads that are prone to the influence of motions and are unable to conduct dynamic measurement. [21,22] Flexible electronic systems have demonstrated their capabilities in adapting skin contour and skin motion, minimizing the issues of motion artifacts and mechanical mismatches between conventional rigid electronic materials and soft skin. They have been demonstrated as varieties of wearable sensing patches to record physical parameters such as temperature, [23,24] humidity, [25][26][27] blood pressure, [28][29][30] and strain [31,32] as well as chemicals such as ions, [33,34] glucose, [35,36] and blood oxygen. [37,38] Flexible ECG systems have also been explored in the context of stretchable electrodes, [39,40] novel conductive electrode materials, [40][41][42][43] capacitive sensing, [44,45] and flexible hybrid electronics. [46][47][48] However, the majority of these ECG systems are based on single lead detection with a small sensing area, lacking the capability to comprehensively probe the hearts from different angles and the compatibility with clinical standards that are built on 12-lead ECG. [49,50] Flexible 12-lead ECG systems may offer precise and comprehensive detection results that abide by the clinical requirements with excellent tolerance to body motion and skin contour. However, such systems have seldomly been reported due to the complexity in constructing flexible systems that cover large surface areas while maintaining high stability in motion and skin deformation. As a result, a flexible 12-lead system in integrating with skin and potential influence factors to the performance of this system has rarely been studied.Here, we developed a flexible 12-lead ECG system that can simultaneously conduct electrocardiogram sensing and threeaxis acceleration monitoring. The system that contains a flexible sensor formed by modularized components and a flexible wireless measurement circuit. The sensing components are screen-printed and assembled to cover almost the entire chest area with adjustable dimensions to adapt to different body shapes. The design of individual components in the sensor Dynamic multilead monitoring of cardiovascular health conditions is challenging due to the complexity of constructing a flexible system that covers large surface areas and synchronizes measurement results from different leads. A flexible 12-lead electrocardiography system that can simultaneously conduct electrocardiogram sensing and 3-axis acceleration monitoring is developed. The system is fabricated through a modularized printing process, resulting in individual modules that can be assembled reversibly through magnetic connectors. Different levels of stretchability and adjustable length of interconnect can accommodate different body statures a...

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“…After manual correction, the following pre-operative HRV measurements were obtained from the 5-min recording: time domain -standard deviation (SD) of the interbeat interval (SDNN), root mean square of successive differences between normal heart beats (RMSSD); frequency domain -low-frequency/high-frequency ratio; and nonlinear domain -SD1, SD2, approximate entropy (ApEn) and sample entropy (SampEn), as previously described. 9,17,18 Briefly, SDNN and RMSSD are time domain measurements, with decreasing SDNN and RMSSD values corresponding to higher sympathetic activity. 9 Conversely, SD1 and SD2 are nonlinear domain measurements that are associated with baroreflex sensitivity, which is the change in interbeat interval per unit change in BP.…”

Section: Methodsmentioning

confidence: 99%

Heart rate variability and haemodynamic factors associated with hypotension during spinal anaesthesia for caesarean delivery

Du¹,

Tan²,

Tan³

et al. 2021

European Journal of Anaesthesiology

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BACKGROUND Hypotension frequently occurs during spinal anaesthesia for caesarean delivery, with potential adverse effects.OBJECTIVE To investigate heart rate variability and haemodynamic factors associated with spinal anaesthesia-induced hypotension.DESIGN Secondary case-control analysis of a randomised study.SETTING Single obstetric centre.PATIENTS Data were obtained from 230 healthy term singleton parturients who underwent elective caesarean delivery under spinal anaesthesia.INTERVENTION With parturients at rest, continuous haemodynamic measurements were recorded using a Nexfin cardiac monitor. Baseline pre-operative values were defined as the average of five minutes of continuous measurements. After initiation of standardised spinal anaesthesia, vasopressors were administered to maintain SBP within 10% of preoperative values. Hypotension was defined as any 10 seconds average SBP less than 80% of pre-operative values from initiation of spinal anaesthesia to foetal delivery. Parturients were classified into cases (hypotensive) or controls (normotensive), and both univariate and multivariable logistic regression models were used to identify independent factors associated with hypotension.MAIN OUTCOME MEASURES Pre-operative standard deviation of the interbeat interval (SDNN), root mean square of successive interbeat difference, low-frequency to high-frequency ratio, SD1, SD2, approximate entropy, sample entropy, mean arterial pressure, SBP, stroke volume variation and systemic vascular resistance index were recorded, as were sensory block height, intravenous fluid volume and vasopressor use between spinal anaesthesia and foetal delivery. RESULTSOf 230 parturients, 113 (49.1%) experienced hypotension. Pre-operative lower SDNN [odds ratio (OR) 0.87, 95% confidence interval (CI) 0.78 to 0.97], higher SD2 (OR 25.06, 95% CI 2.41 to 261.06), and lower SBP (OR 0.98, 95% CI 0.97 to 1.00) were independently associated with hypotension. Between spinal anaesthesia to foetal delivery, lower sensory block height (OR 0.76, 95% CI 0.65 to 0.90) and higher intravenous fluid volume (OR 0.98, 95% CI 0.96 to 0.99 per 15 ml change) were associated with a lower incidence of hypotension. Area under the receiver operating characteristic curve was 0.701.CONCLUSION Pre-operative higher SD2, lower SDNN and lower SBP were associated with hypotension during spinal anaesthesia for caesarean delivery.TRIAL REGISTRATION NCT02277730.

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Heart rate variability: Highlights from hidden signals

Cited by 22 publications

References 43 publications

Evaluation of Heart Rate Variability Parameters During Awake and Sleep in Refractory and Controlled Epileptic Patients

Evaluation of Heart Rate Variability Parameters During Awake and Sleep in Refractory and Controlled Epileptic Patients

A Flexible and Stretchable 12‐Lead Electrocardiogram System with Individually Deformable Interconnects

Heart rate variability and haemodynamic factors associated with hypotension during spinal anaesthesia for caesarean delivery

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