Wave Interval Research Articles

Estimation of melatonin level and core body temperature: heart rate and heart rate variability as circadian rhythm markers

ABSTRACT Because the circadian rhythm is different for each individual depending on what light environment they are exposed to on that day, the circadian rhythm needs to be constantly managed in everyday life. However, the typical circadian markers, changes in melatonin (MLT), and core body temperature (CBT) are difficult to measure 24-hour cycle of daily life. In this study, to propose relatively easy-to-monitor cardiac rhythmicity-related indicators as circadian markers, the biomarkers, including MLT, CBT, heart rate (HR), and heart rate variability (HRV), were collected from 22 Korean men. The MLT and CBT showed the largest positive correlation with R wave-to-R wave (RR) interval (Pearson’s r = .620, p < .001) and HR (Pearson’s r = .476, p < .001), respectively. In addition, the difference between the peak times of the seventh-order fitted MLT (adjusted R2 = .960, peak time 04:56) and RR interval (adjusted R2 = .960, peak time 04:35) was approximately 21 min; especially, the nadir times of the fitted CBT (adjusted R2 = .961, nadir time 04:55) and HR (adjusted R2 = .934, nadir time 04:52) were almost the same. Therefore, we can confidently say that HR and RR intervals are good indicators for estimating an individual’s circadian rhythm.

Heart Rate Variability Indices as Possible Biomarkers for the Severity of Post-traumatic Stress Disorder Following Pregnancy Loss.

Background: Psychological distress, such as posttraumatic stress disorder (PTSD), is commonly evaluated using subjective questionnaires, a method prone to self-report bias. The study's working hypothesis was that levels of autonomic dysfunction determined by heart rate variability (HRV) measures are associated with the severity of PTSD in women following pregnancy loss.Methods: This was an observational prospective cohort study with 53 patients enrolled. The DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) PTSD scale (PCL-5) was used to assess the severity of PTSD in women after pregnancy loss. The cardiac autonomic function was assessed using HRV measurements during a deep breathing test using an HRV scanner system with wireless ECG enabling real-time data analysis and visualization. HRV measures were: standard deviation (SD) of normal R-R wave intervals [SDNN, ms], square root of the mean of the sum of the squares of differences between adjacent normal R wave intervals [RMSSD, ms], and the number of all R-R intervals in which the change in consecutive normal sinus intervals exceeds 50 milliseconds divided by the total number of R-R intervals measured [pNN50 = (NN50/n-1)*100%] [pNN50%].Results: The PCL-5 scores had a statistically significant association with HRV indices (SDNN; RMSSD, and pNN50%). Patients with PTSD had similar mean heart rate values as compared to patients without PTSD (PCL-5), but significantly higher SDNN [median[IQR, interquartile range]: 90.1 (69.1–112.1) vs. 52.5 (36.8–65.6)], RMSSD [59.4 (37.5–74.9) vs. 31.9 (19.3 – 44.0)], and PNN50% values [25.7 (16.4–37.7) vs. 10.6 (1.5–21.9)]. The SDNN of the deep breathing test HRV was effective at distinguishing between patients with PTSD and those without, with an AUC = 0.83 +/− 0.06 (95 % CI 0.94, p = 0.0001) of the ROC model.Conclusions: In this study, HRV indices as biomarkers of cardiac dysautonomia were found to be significantly related to the severity of PTSD symptoms in women after pregnancy loss.

Evaluation of cardiotoxicity in Amazonian fish Bryconops caudomaculatus by acute exposure to aluminium in an acidic environment.

Aluminium (Al) is soluble in acidic waters and may become toxic to organisms. In this study, the acute effects of two Al concentrations were evaluated in the Amazonian fish Bryconops caudomaculatus. Antioxidant responses and lipid damage were assessed in gills, liver and muscle, along with the electrocardiography (ECG) and characterization of cardiac complex and wave intervals. Fish were essayed as follows: two control groups at neutral and acidic pH and two exposure groups at acidic pH (0.3 mg/L and 3.0 mg/L Al). Water samples were collected at 0h, 24h and 48h, for chloride (Cl-), fluoride (F-) and sulphate (SO42-) ion analyses, while total Al was quantified in muscle. Concentrations of Cl- and SO42- were constant over time whereas F- was not detected. Total Al concentrations in water and muscle were concentration-dependent. Antioxidant responses, total antioxidant capacity against peroxyl radicals (ACAP) and glutathione S-transferase were not triggered in fish tissues exposed to 0.3 mg/L Al; however, fish exposed to 3.0 mg/L Al presented increased and reduced ACAP in gills and liver, respectively. No changes in lipoperoxidation levels occurred among groups. Fish exposed to 0.3 mg/L Al showed prolonged intervals in ECG as a reflection of low heart rate (HR), with sinus bradycardia. Moreover, there was a marked prolongation of the PQ interval (time between the atrial activity and the start of ventricular activity), indicating interference on the cardiac cell automaticity. Fish exposed to the highest concentration of Al showed reduced wave intervals as a consequence of increased HR, with sinus arrhythmia, while ECG tracings did not present P waves (atrial contraction), indicating an atrioventricular blockade. In conclusion, 48h exposure sufficed to cause cardiotoxicity in B. caudomaculatus at either Al concentration. However, as oxidative stress was not observed, such cardiac alterations seem to be reversible under the experimental conditions established herein.

Društvena i ekonomska kriza kroz prizmu Kondratijevljeve teorije dugih talasa

The scale of the modern economic crisis has refuted theories of a linear and self-regulating market. Adam Smith's "invisible hand" turned out to be nothing but a myth which served the purpose of maintaining the monopoly. In pursuit of alternative interpretations, we have decided that this paper should investigate the scale of crisis in the world and how major powers respond to it, as seen through Kondratiev long wave theory. Initially, we present the basic theoretical presumptions, to which we added modern sociological interpretations. This section is followed by explanations of socio-technological factors which are crucial for the intervals of long waves. Finally, we give a general presentation of the relationship between major powers and their future geocultural strategies: This paper aims to fathom the mechanisms of structurally conditioned crises and to indicate the need to apply Kondratiev long-wave theory when creating highest-level strategic documents.

Solar Orbiter observations of the Kelvin-Helmholtz waves in the solar wind

Context.The Kelvin-HeImholtz (KH) instability is a nonlinear shear-driven instability that develops at the interface between shear flows in plasmas. KH waves have been inferred in various astrophysical plasmas, and have been observed in situ at the magnetospheric boundaries of solar-system planets and through remote sensing at the boundaries of coronal mass ejections.Aims.KH waves are also expected to develop at flow shear interfaces in the solar wind. While they were hypothesized to play an important role in the mixing of plasmas and in triggering solar wind fluctuations, their direct and unambiguous observation in the solar wind was still lacking.Methods.We report in situ observations of quasi-periodic magnetic and velocity field variations plausibly associated with KH waves using Solar Orbiter during its cruise phase. They are found in a shear layer in the slow solar wind in the close vicinity of the heliospheric current sheet. An analysis was performed to derive the local configuration of the waves. A 2D magnetohydrodynamics simulation was also set up with approximate empirical values to test the stability of the shear layer. In addition, magnetic spectra of the event were analyzed.Results.We find that the observed conditions satisfy the KH instability onset criterion from the linear theory analysis, and its development is further confirmed by the simulation. The current sheet geometry analyses are found to be consistent with KH wave development, albeit with some limitations likely owing to the complex 3D nature of the event and solar wind propagation. Additionally, we report observations of an ion jet consistent with magnetic reconnection at a compressed current sheet within the KH wave interval. The KH activity is found to excite magnetic and velocity fluctuations with power law scalings that approximately followk−5/3andk−2.8in the inertial and dissipation ranges, respectively. Finally, we discuss reasons for the lack of in situ KH wave detection in past data.Conclusions.These observations provide robust evidence of KH wave development in the solar wind. This sheds new light on the process of shear-driven turbulence as mediated by the KH waves with implications for the driving of solar wind fluctuations.

Protocolo diagnóstico de las canalopatías

Channelopathies are a set of anomalies that affect cellular ion channels. Although they can be acquired, those which are most cardiologically relevant are of genetic origin. They affect certain channels of the myocytes or the specific cardiac conduction system. Although their prevalence may not be very high, their clinical repercussions are very important, because most of them are associated with the onset of polymorphic ventricular tachycardias and sudden death, many times in children and young adults. The baseline ECG has a key diagnostic role as it is the phenotypic/electrical expression of the affected channels, giving rise on many occasions to anomalies in the J point, ST segment, T wave, or QT interval. The diagnosis of the affected genes is another key element in its management, given the possible familial repercussions. Therapeutic management can be both primary, for preventing lethal arrhythmic events, and secondary, if the patient has survived one. For many, an implantable automatic defibrillator is a first-line indication.

Metabolic low-frequency oscillation and abbreviated protocol for estimating REE by indirect calorimetry in healthy adults.

The aim of this study is to propose a new wave protocol to identify low-frequency oscillations for evaluating resting energy expenditure (REE) and compare its performance with the 5-min interval abbreviated protocol and standard protocol. Consecutive 20-min indirect calorimetry (IC) was used to collect metabolic data from 23 women and 37 men (between 23 and 43 yr old). Sliding window filter algorithms were used to eliminate noise. Three protocols were used to evaluate REE: averaging the data between two consecutive waves (wave protocol), averaging the second 5-min intervals (interval protocol), and averaging the last 15-min REE (standard protocol). Based on 60 healthy participants' metabolic data, compared with the interval protocol, the wave protocol showed better consistency with the standard protocol. The mean bias (limits of agreement) using the wave protocol was 0.3458% (-7.817% to 8.509%), and that using the interval protocol was -1.720% (-16.06% to 12.62%). The time required to evaluate REE with the wave protocol and interval protocol was measured. The measurement time for the interval protocol was 10 min, while the average measurement time for the wave protocol was 9.75 min. We recommend the wave protocol for estimating REE in healthy people. This abbreviated protocol can identify low-frequency oscillations and consider individual differences to more accurately reflect the baseline REE compared with the interval protocol. When compared with the standard protocol, the measurement time of the wave protocol was reduced by nearly half [from 20 min (standard protocol) to 9.75 min].NEW & NOTEWORTHY For estimating REE by indirect calorimetry, to shorten the measurement time, a consideration of low-frequency oscillations is essential. Based on that we proposed a new abbreviated protocol named wave protocol, which showed accuracy approaching that of the standard protocol with a measurement time close to that of the interval abbreviated protocol.

Comparative Review of the Correlation Between Electroneurography, Electromyography, Hematology Tests, or the Heart Rate Variability Test, with an Improvement in the Severity of Bell’s Palsy Symptoms

Background: In this retrospective study, we aimed to determine which diagnostic tests were associated with an improvement in Bell’s palsy symptoms. Methods: There were 30 patients who visited Kyung Hee University Korean Medicine Hospital from April 1, 2017 to February 29, 2020, and who received East-West collaboration treatment for Bell’s palsy. The tests included electroneurography (ENoG), electromyography (EMG), hematology, and heart rate variability (HRV) results which were used to determine if any test correlated with improvement of Bell’s palsy symptoms. Results: The initial severity of symptoms did not correlate with the tests performed, with the exception of mean corpuscular hemoglobin concentration (p = 0.013). For both ENoG for oculi degeneration and mean EMG tests, the rate of nerve degeneration showed a significant negative correlation with the improvement of Bell’s palsy symptoms. Amongst the HRV test indicators, the square root of the mean of the sum of the squares of differences between the adjacent normal R-R wave interval, the standard deviation of intervals, total power, very low frequency, and high frequency of the wave was negatively correlated with improvement of Bell’s palsy symptoms. Similarly, glycosylated hemoglobin Type A1c (HbA1c) and erythrocyte sedimentation rate (ESR) showed a negative correlation with improvement of symptoms of Bell’s palsy. With the exception of HbA1c and ESR, the remaining hematology test results showed no significant difference when comparing before and after treatment. Conclusion: ENoG, EMG, HRV test, HbA1c, and ESR negatively correlated with improvements in Bell’s palsy symptoms and may determine the prognosis of Bell’s palsy.

Distribution, characteristics, and processes of formation of sediment waves along the Indian north-eastern continental margin

Muddy, upslope-migrating sediment waves, with their crestal lines parallel to the bathymetric contours, are the dominant geomorphic elements in the entire lower slope along the Indian north-eastern continental margin. Wave dimensions are maximum with high but differing degrees of sediment accretions on the upslope and downslope sides of wave crests and with most upslope wave migrations in the northeastern part of the study area, having relatively low seafloor gradients. The wave dimensions decrease with lower as well as differing degrees of sediment accretions on both sides of wave crests and with lower upslope wave migrations in the southwestern parts of the study area, having steeper seafloor gradients. Within each area of the lower slope, starting from updip, wave dimensions increase to their maximum at some distance downdip with optimal low seafloor gradients. Farther downdip, the wave dimensions decrease even with lower seafloor gradients continuing. Also, within each area, at the base of the wave intervals, the waves are small and grow into larger features with more sediment accretions in the upper intervals.The distribution and characteristics of sediment waves observed along the Indian margin are indicative of deposition by down-slope moving, unconfined turbidity currents that have evolved from other sediment gravity flows derived from several point sources updip. Along-slope bottom currents are least likely agents of wave deposition here. We interpret that the spatial and temporal variations in wave dimensions are due to the variations in seafloor gradients, turbidity current flow characteristics, frequency, duration and total number of flow events in space and time.

Identification of Coastal Sand Deposits From Tsunamis and Storm Waves Based on Numerical Computations

AbstractTsunami and storm deposits can be utilized for estimating inundation zones and recurrence intervals of extreme waves in modern, historic, and prehistoric times. However, the distribution of these deposits is extremely complex and affected by various factors such as the size of the waves, topography, bathymetry, and the supply of sediment and its properties. Here, we use numerical computations to identify the key factors affecting the inundation extent of tsunamis and storm waves, and which subsequently govern the distribution of the corresponding coastal sand deposits. The results demonstrate that the overall topography slope has the most significant impact on the inundation extent of tsunamis and storm waves and subsequently the inland distribution distance of the transported deposits. The existence of onshore sediment sources is crucial for estimating the maximum extent of storm deposits because only a limited amount of sediment is carried inland by the storm waves. In contrast, the presence of onshore sediment sources is less critical for the delineation of the maximum distribution envelope of tsunami deposits compared to other parameters. The parameters that mainly control the sediment deposit volume over land under tsunami and storm wave conditions are the grain size and wave height, respectively. Our computed results are summarized using the Dean number, Shields number, and Iribarren number showing an inter‐connectivity between topography, input wave characteristic, and onshore distributions of both types of deposits. Despite some simplifications, this approach can efficiently lead to an identification and reconstruction of past catastrophic wave events.

Liddle Syndrome in a Six-Year-Old Girl: A Case Report

Liddle syndrome is a cause of hypertension among children due to mutation in the epithelial sodium channels (ENaC) located in the kidneys. It typically presents with hypertension, hypokalemia, metabolic alkalosis with low renin and aldosterone levels. Although, most cases are children, but adults also present with this disorder owing to late diagnosis. Amiloride and triamterene efficiently improve the condition. Here we present the case of a 6-year-old girl admitted with history of hypertension, diarrhea, vomiting, weakness and palpitations on and off for the last four years. Laboratory investigations revealed metabolic alkalosis, decreased renin and aldosterone levels, hypokalemia and an inverted T wave, U wave and prolonged QT interval on ECG. Any pediatric case presenting with hypertension and electrolyte imbalance should promptly raise suspicion of Liddle syndrome. Timely diagnosis and management play a key role in reducing morbidity and mortality.

Expert consensus document on automated diagnosis of the electrocardiogram: The task force on automated diagnosis of the electrocardiogram in Japan. Part 1: Nomenclature for diagnosis and abnormal findings.

As these terms should accurately represent the abnormal findings and conditions as much as possible, we propose to unify these terms into terminologies that are not confusing and easy to understand for everyone.

Electron Bernstein waves and narrowband plasma waves near the electron cyclotron frequency in the near-Sun solar wind

Context. Recent studies of the solar wind sunward of 0.25 AU reveal that it contains quiescent regions, with low-amplitude plasma and magnetic field fluctuations, and a magnetic field direction similar to the Parker spiral. The quiescent regions are thought to have a more direct magnetic connection to the solar corona than other types of solar wind, suggesting that waves or instabilities in the quiescent regions are indicative of the early evolution of the solar wind as it escapes the corona. The quiescent solar wind regions are highly unstable to the formation of plasma waves near the electron cyclotron frequency (fce). Aims. We examine high time resolution observations of these waves in an effort to understand their impact on electron distribution functions of the quiescent near-Sun solar wind. Methods. High time resolution waveform captures of near-fce waves were examined to determine variations of their amplitude and frequency in time as well as their polarization properties. Results. We demonstrate that the near-fce wave intervals contain several distinct wave types, including electron Bernstein waves and extremely narrowband waves that are highly sensitive to the ambient magnetic field orientation. Using the properties of these waves, we suggest possible plasma wave mode classifications and possible instabilities that generate these waves. The results of this analysis indicate that these waves may modify the cold core of the electron distribution functions in the quiescent near-Sun solar wind.

IoT-enabled cloud-based real-time remote ECG monitoring system

Statistical reports all around the world have deemed cardiovascular diseases (CVDs) as the largest contributor to the death count. The electrocardiogram (ECG) is a widely accepted technology employed for investigation of CVDs of the person. The proposed solution deals with an efficient internet of things (IoT) enabled real-time ECG monitoring system using cloud computing technologies. The article presents a cloud-centric solution to provide remote monitoring of CVD. Sensed ECG data are transmitted to S3 bucket provided by Amazon web service (AWS) through a mobile gateway. AWS cloud uses HTTP and MQTT servers to provide data visualisation, quick response and long-live connection to device and user. Bluetooth low energy (BLE 4.0) is used as a communication protocol for low-power data transmission between device and mobile gateway. The proposed system is implemented with filtering algorithms to ignore distractions, environmental noise and motion artefacts. It offers an analysis of ECG signals to detect various parameters such as heartbeat, PQRST wave and QRS complex intervals along with respiration rate. The proposed system prototype has been tested and validated for reliable ECG monitoring remotely in real-time.

Effects of treatment with hydroxychloroquine and azithromycin on the index of cardiac electrophysiological balance in patients with COVID-19: A retrospective cohort study

Background/Aim: The common cardiac toxicities of hydroxychloroquine (HCQ) and azithromycin (AZ) are not well defined in COVID-19 patients. Index of cardiac electrophysiological balance (iCEB) is used as a novel risk marker for drug-induced arrhythmias. The purpose of this study was to evaluate ventricular repolarization using iCEB and other conventional ECG parameters such as the end of electrocardiographic T wave (Tp-e) interval, Tp-e/QT ratio, and Tp-e/ heart rate-corrected QT (QTc) ratio in COVID-19 patients treated with HCQ and AZ. Methods: This retrospective study enrolled 164 patients diagnosed with COVID-19 pneumonia in the Emergency Department (ED) and then transferred to the ward or the intensive care unit in April 2020. Results: A total of 164 patients with a mean age of 47 (18) years (range: 18-97 years) included 83 (50.6%) females. There were 38 and 126 patients in Groups HTQ and HTQ+AZ, respectively. On the 5th day of hospitalization, all patients’ heart rates were significantly lower (P

Assessment of the atrial adenosinergic system in the onset of atrial fibrillation: A pre-clinical study in a mouse model with genetic susceptibility to atrial fibrillation

Atrial fibrillation (AF) is a multifactorial sustained cardiac arrhythmia with genetic predisposition. Genome-wide association studies (GWAS) have identified loci near key cardiac transcription factors encoding genes (TBX5, GATA4, NKX2.5) associated with AF risk. Consistently, adult-specific Tbx5 knockout mice showed primary spontaneous and sustained AF, induced by calcium handling abnormalities. The adenosinergic system may be implicated in the onset of AF. We previously showed that adenosine plasma levels increase in persistent AF, and atrial adenosine receptor overexpression is associated with reentry mechanisms. While calcium signaling proteins and potassium channels are major effectors of the adenosinergic system, and also triggers of AF, the link between TBX5, AF and the adenosinergic system has not yet been studied. To assess how the intra-atrial adenosinergic system is associated with a higher susceptibility to atrial fibrillation in a mouse model. Transgenic Cx40-CreERT2::Tbx5 floxed/floxed mice allow conditional deletion of Tbx5 in atria and the ventricular conduction system. Cre-mediated recombination was induced by intraperitoneal injection of tamoxifen in control (Cx40-CreERT2::Tbx5++) and mutant newborn mice. AF was investigated by surface ECGs between 2 weeks and 3 months. The adenosinergic system was assessed by adenosine plasma measurement, in vivo pharmacological tests, immunofluorescence and western blot analyses. At 2 weeks, prolonged P wave and PR interval durations ( P < 0.001; P = 0.03, respectively) and reduced P wave amplitude ( P = 0.01) were measured in transgenic mice ( n = 9) compared to controls ( n = 8). AF episodes were more frequently observed in conditional mutant mice (33% vs. 0%; P = 0.21). Tbx5 deletion specifically in atria increases susceptibility for atrial fibrillation confirming our model as a good one to study the role of the adenosinergic system in AF.

Menthol exposure induces reversible cardiac depression and reduces lipid peroxidation in the heart tissue of tambaqui Colossoma macropomum

Exposure to menthol is expected to alleviate physiological and oxidative stress in fish. Yet, its effects as an anesthetic-like compound on the heart function and associated physiological and biochemical changes still need further clarification. This study aimed to analyze the effects of menthol on the cardiac function and oxidative stress responses of Colossoma macropomum exposed to short-term baths. Fish were divided into three groups: control, menthol-exposed fish (40, 60 and 80 mg L−1) and fish in recovery. The electrocardiogram (ECG) tracing patterns, wave intervals (RR; QT), complex duration (QRS) and heart rate were assessed after 5 min recordings throughout exposure and recovery. Total antioxidant capacity against peroxyl radicals (ACAP), glutathione S-transferase (GST) activity and lipoperoxidation (LPO) levels were also evaluated in the heart tissue. All concentrations of menthol depressed the heart rate and prolonged RR and QT intervals in a concentration-dependent fashion. QRS complex duration was only reduced at the highest dose of menthol. During recovery, heart rate and mean amplitude were still reduced at 60 or 80 mg L−1 menthol, whereas wave intervals were still longer at these concentrations. Notwithstanding, QRS complex resumed its normal duration during recovery. GST activity and ACAP were unchanged in fish exposed to menthol. However, LPO reduced in fish exposed to 40 and 60 mg L−1 menthol. In conclusion, all concentrations of menthol induced anesthesia in C. macropomum without causing mortality, albeit provoking transient cardiac alterations. Menthol at 40 and 60 mg L−1 could be considered suitable concentrations to immobilize fish as they not only did not compromise cardiac function but reduced LPO in the heart. Yet, menthol at 80 mg L−1 or higher doses should be avoided as there is a potential for the emergence of a life-threatening cardiac depression and oxidative stress.

Cross-Domain Transfer Learning for PCG Diagnosis Algorithm.

Cardiechema is a way to reflect cardiovascular disease where the doctor uses a stethoscope to help determine the heart condition with a sound map. In this paper, phonocardiogram (PCG) is used as a diagnostic signal, and a deep learning diagnostic framework is proposed. By improving the architecture and modules, a new transfer learning and boosting architecture is mainly employed. In addition, a segmentation method is designed to improve on the existing signal segmentation methods, such as R wave to R wave interval segmentation and fixed segmentation. For the evaluation, the final diagnostic architecture achieved a sustainable performance with a public PCG database.

LINKS BETWEEN VITAMIN D, C REACTIVE PROTEIN, LDL, OXIDIZED LDL AND ECG VARIABLES IN HYPERTENSIVE PATIENTS

Objective: The present paper aimed to assess the relationship of electrocardiographic variables with vitamin D, C reactive protein (CRP), LDL and oxidized LDL level, respectively, in hypertensive patients. Design and method: A total of 40 hypertensive patients underwent standard 12-lead ECG, which enabled measurement of P wave, PR and QT interval and QRS duration, as well as R wave in V5 and V6 and S wave in V1, V2. The following laboratory tests were performed: vitamin D (25-hydroxycholecalciferol: liquid chromatography method), CRP (immunophelometry), LDL (photometric method) and oxidized LDL (ELISA method). Results: QRS complex and heart rate corrected QT interval (QTc) duration were prolonged in 27.5% and 25%, respectively, of the patients. Vitamin D was less than 20 microg/l (D20) in 35% of the patients, and less than 30 microg/l (D30) in 77.5%. Significant correlations were found between vitamin D level and QRS duration (rS = −0.334, p = 0.035), QT (rS = 0.383, p = 0.015), QTc (rS = 0.366, p = 0.020), RV5 (rP = 0.682, p less than 0.001), RV6 (rP = 0.573, p less than 0.001), SV2 (rP = 0.356, p = 0.024). QRS duration correlated with CRP exceeding 0.300 mg/dl (rK = 0.423, p = 0.008). LDL level was significantly associated with a prolonged P wave duration (P120) (rP = −0.327, p = 0.039). No correlation was found between oxidized LDL level and ECG variables. Conclusions: Vitamin D level can provide valuable information about QRS duration, QT interval, R in V5 and V6 and S in V2, CRP about QRS duration, and LDL level about P wave duration. Vitamin D, CRP and LDL level may inform about ventricular arrhythmia and atrial fibrillation risk, respectively, in hypertensive patients.

Determining EMIC Wave Vector Properties Through Multi-Point Measurements: The Wave Curl Analysis.

Electromagnetic ion cyclotron (EMIC) waves play important roles in particle loss processes in the magnetosphere. Determining the evolution of EMIC waves as they propagate and how this evolution affects wave‐particle interactions requires accurate knowledge of the wave vector, k. We present a technique using the curl of the wave magnetic field to determine k observationally, enabled by the unique configuration and instrumentation of the Magnetospheric MultiScale (MMS) spacecraft. The wave curl analysis is demonstrated for synthetic arbitrary electromagnetic waves with varying properties typical of observed EMIC waves. The method is also applied to an EMIC wave interval observed by MMS on October 28, 2015. The derived wave properties and k from the wave curl analysis for the observed EMIC wave are compared with the Waves in Homogenous, Anisotropic, Multi‐component Plasma (WHAMP) wave dispersion solution and with results from other single‐ and multi‐spacecraft techniques. We find good agreement between k from the wave curl analysis, k determined from other observational techniques, and k determined from WHAMP. Additionally, the variation of k due to the time and frequency intervals used in the wave curl analysis is explored. This exploration demonstrates that the method is robust when applied to a wave containing at least 3–4 wave periods and over a rather wide frequency range encompassing the peak wave emission. These results provide confidence that we are able to directly determine the wave vector properties using this multi‐spacecraft method implementation, enabling systematic studies of EMIC wave k properties with MMS.