Cardiovascular response as a marker of environmental stress caused by variations in geomagnetic field and local weather
Abstract
Cardiovascular response as a marker of environmental stress caused by variations in geomagnetic field and local weather Pishchalnikova RY, Gurfinkel YI, Sarimov RM, Vasin AL, Sasonko ML, Matveeva TA, Binhi VN, Baranov MB. Cardiovascular response as a marker of environmental stress caused by variations in geomagnetic field and local weather. Biomedical Signal Processing and Control . 51:401-410. May 2019. doi.org Highlights • A Helmholtz-like magnetic field exposure system adapted for long-term experiments. • Three modes of magnetic field exposure including geomagnetic storm have been used. • Correlations of heart rate with magnetic field are criterion of cardiovascular response. • Maximum cardiovascular response has been detected for the storm mode of exposure. • Time-frequency representation of heart rate for each subject has individual character. Abstract We report the results of a physiological study that include ECG analysis, capillary blood velocity (CBV) data, and blood pressure (BP) measurements obtained under conditions of modified external magnetic field (MF). Each of eight volunteers was sequentially exposed to MFs of three different types for 22 h. A Helmholtz-like MF exposure system was used. The system was specially designed for long-term exposures of human beings to static and low frequency MFs. The MF of the first type reproduced an initially recorded geomagnetic storm (GS). The MF inductions of the other two types were about 55 and 49 μT, which corresponded to the natural local magnetic background and a slightly decreased MF, respectively. In all three cases, the environmental magnetic fluctuations were suppressed by the active Helmholtz system. The variability of RR intervals[ the time elapsed between two successive R-waves of the QRS signal on the electrocardiogram] was considered as a key indicator of cardiovascular response to the MFs and weather conditions. A time-frequency representation (TFR) and a frequency-frequency representation (FFR) were used for processing of the time series of RR intervals. It turned out that the transformation to TFR makes it possible to obtain the characteristic matrix of RR intervals; such a matrix can be used as a subject identifier. FFR was used to calculate correlations of RR intervals with the components of the MFs. The averaged correlation coefficients of RR intervals with the Bx and By components appeared significantly higher (p < 0.001) during the Storm mode in comparison with control. Thus, it is shown that artificial geomagnetic storm can cause a detectable cardiovascular response. sciencedirect.com
AI evidence extraction
Main findings
In eight volunteers exposed sequentially to three magnetic-field conditions for 22 hours each, correlations between RR intervals and magnetic-field components (Bx and By) were reported to be significantly higher during the simulated geomagnetic storm mode than during control (p < 0.001). The authors conclude that an artificial geomagnetic storm can cause a detectable cardiovascular response, using RR-interval variability as the key indicator.
Outcomes measured
- ECG (RR interval variability)
- Heart rate
- Capillary blood velocity (CBV)
- Blood pressure (BP)
- Correlation of RR intervals with magnetic field components (Bx, By)
Limitations
- Small sample size (eight volunteers).
- Exposure order was sequential; randomization/blinding is not described in the abstract.
- Findings are based on correlations of RR intervals with magnetic-field components; clinical significance is not established in the abstract.
- Details on participant characteristics and selection are not provided in the abstract.
View raw extracted JSON
{
"publication_year": 2019,
"study_type": "other",
"exposure": {
"band": "ELF",
"source": "geomagnetic field simulation (Helmholtz-like exposure system)",
"frequency_mhz": null,
"sar_wkg": null,
"duration": "22 h (each of three exposure types, sequentially)"
},
"population": "Eight volunteers",
"sample_size": 8,
"outcomes": [
"ECG (RR interval variability)",
"Heart rate",
"Capillary blood velocity (CBV)",
"Blood pressure (BP)",
"Correlation of RR intervals with magnetic field components (Bx, By)"
],
"main_findings": "In eight volunteers exposed sequentially to three magnetic-field conditions for 22 hours each, correlations between RR intervals and magnetic-field components (Bx and By) were reported to be significantly higher during the simulated geomagnetic storm mode than during control (p < 0.001). The authors conclude that an artificial geomagnetic storm can cause a detectable cardiovascular response, using RR-interval variability as the key indicator.",
"effect_direction": "harm",
"limitations": [
"Small sample size (eight volunteers).",
"Exposure order was sequential; randomization/blinding is not described in the abstract.",
"Findings are based on correlations of RR intervals with magnetic-field components; clinical significance is not established in the abstract.",
"Details on participant characteristics and selection are not provided in the abstract."
],
"evidence_strength": "low",
"confidence": 0.7800000000000000266453525910037569701671600341796875,
"peer_reviewed_likely": "yes",
"stance": "concern",
"stance_confidence": 0.6999999999999999555910790149937383830547332763671875,
"summary": "This physiological study exposed eight volunteers to three long-duration magnetic-field conditions using a Helmholtz-like system, including a mode reproducing a recorded geomagnetic storm. RR-interval variability was analyzed with time-frequency and frequency-frequency representations, and correlations with magnetic-field components were computed. Correlations of RR intervals with Bx and By were reported to be significantly higher during the storm mode than control, which the authors interpret as a detectable cardiovascular response to an artificial geomagnetic storm.",
"key_points": [
"Eight volunteers underwent ECG, capillary blood velocity, and blood pressure measurements under modified external magnetic-field conditions.",
"A Helmholtz-like exposure system was designed for long-term exposure to static and low-frequency magnetic fields in humans.",
"Three exposure modes were used, including one reproducing an initially recorded geomagnetic storm and two near-background conditions (~55 and ~49 µT).",
"Environmental magnetic fluctuations were suppressed by the active Helmholtz system in all conditions.",
"RR-interval variability was treated as the key indicator of cardiovascular response to magnetic fields and weather conditions.",
"Average correlations of RR intervals with Bx and By were reported to be significantly higher during the storm mode than during control (p < 0.001)."
],
"categories": [
"Human laboratory study",
"ELF/Static magnetic fields",
"Cardiovascular physiology"
],
"tags": [
"Geomagnetic Storm Simulation",
"Helmholtz Coil Exposure System",
"Static Magnetic Field",
"Low Frequency Magnetic Field",
"Heart Rate Variability",
"RR Intervals",
"Electrocardiogram",
"Blood Pressure",
"Capillary Blood Velocity",
"Time-Frequency Analysis",
"Correlation Analysis"
],
"keywords": [
"geomagnetic field",
"geomagnetic storm",
"magnetic field exposure",
"Helmholtz-like system",
"RR interval variability",
"heart rate",
"ECG",
"capillary blood velocity",
"blood pressure",
"time-frequency representation",
"frequency-frequency representation"
],
"suggested_hubs": [],
"social": {
"tweet": "Human lab study (n=8) used a Helmholtz-like system to simulate a geomagnetic storm and near-background magnetic fields for 22 h each. RR-interval correlations with magnetic-field components (Bx, By) were higher during the storm mode vs control (p<0.001), suggesting a detectable cardiovascular response.",
"facebook": "A small physiological study exposed eight volunteers to three long-duration magnetic-field conditions using a Helmholtz-like system, including a simulated geomagnetic storm. The authors report higher correlations between RR-interval variability and magnetic-field components during the storm mode compared with control (p<0.001), interpreting this as a detectable cardiovascular response.",
"linkedin": "Biomedical Signal Processing & Control (2019) reports a human laboratory exposure study (n=8) using a Helmholtz-like system to reproduce a recorded geomagnetic storm and compare it with near-background magnetic-field conditions. Using time-frequency methods on RR intervals, the authors found higher RR–Bx/By correlations during the storm mode vs control (p<0.001), concluding a detectable cardiovascular response under the simulated storm condition."
}
}
AI can be wrong. Always verify against the paper.
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