Heart rate and blood pressure variability in subjects with vasovagal syncope (original) (raw)
Related papers
24-Hour Heart Rate Variability in Patients with Vasovagal Syncope
Pacing and Clinical Electrophysiology, 2000
Since alterations in the autonomic nervous system are thought to play a major role in the pathogenesis of vasovagal syncope, we characterized the chronic autonomic profile of 44 patients with syncope and 20 healthy subjects by means of heart rate variability using 24-hour Holter recordings (time-and frequency-domain indexes), and evaluated whether the different types of responses to tilting (vasodepressive versus cardioinhibitory) could be associated with different cardiac autonomic patterns. Twenty-three patients exhibited a positive response to tilting, which was vasodepressive in 11 patients and cardioinhibitory in 12 patients. All vasodepressive patients had a standard deviation of the averages ofNN (SDANN) intervals in all 5-minute segments lower than 100 ms. Patients with vasodepressive syncope also had significantly lower values of RMSSD (the 24hour square root of the mean of the sum of the squares of differences between adjacent normal RR intervals) than those with cardioinhibitory response, and lacked the day-night rhythm of the low frequency/high frequency ratio. However, only SDANN values correctly identified patients with vasodepressive response to tilting. We conclude that (1) the population of patients with vasovagal syncope is heterogeneous, (2) patients with vasodepressive syncope have a peculiar chronic autonomic profile as assessed by 24-hour heart rate variability analysis, and (3) the evaluation of the autonomic profile in 24-hour Holter recordings could be of value in the diagnosis of patients with syncope.
Heart rate variability and heart rate turbulence in patients with vasovagal syncope
Kardiologiia
Aim The autonomic nervous system plays an important role in the pathogenesis of vasovagal syncope, but studies on the effect of basal autonomic tone have found confusing results. The aim of this study was to investigate the effect of basal autonomic functions, as assessed by heart rate variability (HRV) and heart rate turbulence (HRT), in patients with vasovagal syncope.Material and methods Patients who underwent head-up tilt test (HUTT) due to unexplained syncope and who had a 24 hr Holter ECG recording in the same period were retrospectively analyzed. Patients with diabetes, a history of myocardial infarction, heart failure, orthostatic hypotension, atrial fibrillation, or use of vasoactive drugs, such as beta blockers, were excluded from the study. 161 patients who met these criteria were included in the study. Time domain HRV parameters from Holter ECG recordings and HRT parameters from patients with sufficient number of ventricular premature contractions were measured.Res...
Recurrence plot of heart rate variability signal in patients with vasovagal syncopes
Biomedical Signal Processing and Control, 2016
Currently, heart rate variability (HRV) is commonly evaluated using time and frequency domain analysis in the clinical practice. Due to the fact that cardiovascular system is regulated by the autonomic nervous system (ANS) that also influences HRV, however exhibits rather nonlinear behaviour, it appears more appropriate to apply nonlinear methods to evaluate functioning of ANS. This study presents recurrence analysis as a tool to test the presence of ANS dysfunction that is responsible i.e. for orthostatic (vasovagal) syncope by which abnormal HRV has been demonstrated in the past. Study included 18 patients that experienced vasovagal syncope (mean age 23.7 ± 5.2 years) and 18 healthy subjects (mean age 24.5 ± 3.2, p = 0.85). In all tested subjects, ECG recording was performed during active orthostatic test that comprised two phases (5 min of resting in a supine position and 5 min of active standing). Sequence of R-R intervals (time intervals between two consecutive heart beats derived from ECG) was analysed using standard time (mean RR, mean HR, SDNN, SDHR, RMSSD, NN50 and pNN50) and frequency domain (LF, HF and LF/HF ratio) analysis. Moreover, recurrence analysis was performed (RATIO, DIV, AVDL, MAXV, DET, ENTR, LMAX, TT and LAM). Frequency domain analysis did not demonstrate significant difference between the two groups in any of the parameters during both phases of the test. On the contrary, both time domain analysis and recurrence analysis showed comparable findings in both groups during resting phase of the orthostatic test with a significant change of most tested parameters after stand-up. As the use of time domain HRV may be perceived as problematic regarding their interpretation in short ECG recordings, recurrence analysis appears to be a sensitive tool for detecting ANS dysfunction in patients with vasovagal syncope.
Entropy, 2015
Sample entropy (SampEn) was reported to be useful in the assessment of the complexity of heart rate dynamics. Permutation entropy (PermEn) is a new measure based on the concept of order and was previously shown to be accurate for short, non-stationary datasets. The aim of the present study is to assess if SampEn and PermEn obtained from baseline recordings might differentiate patients with various outcomes of the head-up tilt test (HUTT). Time-domain heart rate variability (HRV) indices and several nonlinear parameters were calculated using 500 RR interval-long ECG recordings done before tilting in patients with a history suggesting vasovagal syncope. Groups of patients with so-called cardiodepressive vasovagal syncope (VVS_2) during HUTT and patients who did not faint during the test were compared. Two types of HUT tests were analyzed: with spontaneous (SB) or controlled breathing (CB). In our study, SampEn was higher in VVS_2 patients during SB, and PermEn was higher in VVS_2 patients during CB. Irrespective of the type of breathing during the test, SampEn and PermEn were similar in patients with the Entropy 2015, 17 1008 same type of reaction during HUTT. The use of several entropy-based parameters seems to be useful in HRV assessment in patients with vasovagal fainting.
Role of Vagal Control in Vasovagal Syncope
Pacing and Clinical Electrophysiology, 2003
SUZUKI, M., ET AL.: Role of Vagal Control in Vasovagal Syncope. The vasovagal reaction is thought to be caused by sympathetic withdrawal and vagal augmentation. While measurements of muscle sympathetic nerve activity support sympathetic withdrawal in tilt induced syncope, the results of previous attempts to quantify vagal control using spectral analyses of heart rate variability (HRV) remain controversial. The sampling period used in the HRV studies is related to the discordant results. In the present study, HRV was computed every second using wavelet transformation to clarify the role of vagal control in tilt induced syncope during the 80-degree head-up tilt test (positive: 10 patients with vasovagal syncope; negative: 10 patients with vasovagal syncope, and 10 control subjects). Autonomic modulations were assessed using the absolute power of the low frequency (LF) (0.04-0.15 Hz) and high frequency (HF) (0.15-2.00 Hz) oscillatory components of R-R variability. Although the LF did not change during the tilt procedure, a decrease in the systolic arterial pressure (SAP) and increases in the R-R interval and HF were observed for the last 30 seconds before the tilt induced syncope in the tilt-positive group. Analyzing the hemodynamic measurements and spectral indices for the last 5 minutes preceding the tilt induced syncope, the study found that the SAP, R-R interval, and HF changed simultaneously during the 30second period immediately before the tilt induced syncope. Further, the HF was positively correlated with the R-R interval and negatively correlated with the SAP. In conclusion, continuous spectral analysis of the R-R interval demonstrated increased vagal influence on the heart in tilt induced syncope. (PACE 2003; 26[Pt. I]:571-578) vasovagal syncope, head-up tilt test, autonomic nervous system, spectral analysis, wavelet transformation
The Egyptian Journal of Hospital Medicine
Background: For a long time, researchers have employed head-up tilt to analyze how the heart and blood pressure react to different positions. The vasovagal reflex is responsible for the most prevalent type of reflex syncope, known as vasovagal syncope (VVS) or neurocardiogenic syncope. Objective: The goal of teaching patients to notice prodromal symptoms and doing suitable physical counter-maneuvers (PCMs) to increase blood pressure in order to prevent or postpone attacks is to reduce the likelihood of future attacks. Patients and methods: In a case-control study, fifty-seven subjects were enrolled in the study. Thirty-five patients were in 1 st case group with recurrent history of presyncope or syncope and positive tilt test. Twenty-two age matched healthy subjects were in 2 nd control group. All underwent head up tilt testing (HUTT). Results: there was a statistical significance increase in LF power during P2 in cases compared to controls and also significant increase in LF/HF ration in P1 and P2 reflecting the high sympathetic predominance just preceding the episode of syncope. The magnitude of effect of LFP2, LF/HF at rest and Δ LF between P2 and P1, Δ LF/HF between P1 and R was high denoting the rapid autonomic alteration resulting from postural and stressful conditions preceding the occurrence of syncope. Conclusion: Variability in heart rate provides information about the autonomic nervous system's health (ANS). How much the heart rate (HR) varies tells us about how well the nervous system regulates the heart rate and how quickly the heart can react to external stimuli.
Journal of Cardiovascular and Thoracic Research
Introduction: Autonomic changes play an essential role in the genesis of neurally mediated syncope (NMS). The aim of this study was to compare the changes of the autonomic nervous system (ANS) by measuring spectral indices of beat-to-beat systolic blood pressure and heart rate variability (SBPV and HRV) in ranges of low frequency (LF), high frequency (HF), and the LF/HF ratio during head-up tilt test (HUTT) in patients with and without a syncope response. Methods: In this case-control study of 46 patients with a suspected history of unexplained syncope, data were recorded separately during the typical three phases of HUTT. Patients who developed syncope were designated as the case group and the rest as the control group. Results: Thirty one patients experienced syncope during HUTT. Resting HRV and SBPV indices were significantly lower in cases than controls. After tilting in the syncope group, both HF and LF powers of SBPV showed a significant and gradual decrease. LF/HF in HRV incr...
Heart Rate Variability During Sleep in Patients with Vasovagal Syncope
Pace-pacing and Clinical Electrophysiology, 2005
Background: There are a few studies showing no significant heart rate variability (HRV) over a 24-hour period in vasovagal syncope (VVS) patients, but no research has examined HRV and its sympathetic and parasympathetic components during rapid eye movement (REM) and non-REM sleep. The authors hypothesized that REM sleep might be a critical state in which VVS patients would show abnormal responses.Objectives: To analyze the sympathetic and parasympathetic components of HRV during REM and SWS in patients with VVS compared to normal subjects, and in patients with positive HUTT compared to negative ones.Methods: Thirty-seven VVS patients and 20 normal age-matched controls were submitted to polysomnography with 24-hour Holter monitoring to assess HRV. Time and frequency domain techniques were carefully performed for 24 hours and during Stages 3 and 4 of REM and non-REM sleep. Variation of sympathetic activity index (VSAI) was defined as the difference in the low frequency (LF) component of HRV between REM and Stages 3 and 4 of non-REM sleep. An analysis of variance was performed to compare patients and controls; patients with positive and negative head-up tilt testing.Results: The LF component was lower in syncope compared to normal patients (1,769.54 ± 1,738.17, 3,225.37 ± 2,585.05, respectively, P = 0.03). There was a significant decrease in VSAI in the syncope group compared to the control group (−539.39 ± 1,930.78, 1,268.10 ± 2,420.20, respectively, P = 0.01). The other sleep variables analyzed including very LF, high frequency, low frequency/high frequency and time domain parameters did not reach statistical significance. Syncope patients also showed an increase in slow wave sleep (28.2 ± 10.5, 19.7 ± 7.8, P = 0.01).Conclusions: VVS patients exhibited sympathetic suppression during REM sleep. Possible mechanisms are discussed in this article.