Long-term Electrocardiographic Monitoring Research Articles

Diagnostics and treatment of syncope

The 2018 guidelines of the European Society of Cardiology (ESC) provide improved algorithms for the diagnostics and treatment of syncope. New guidelines on ventricular tachycardia, on the prevention of sudden cardiac death and on cardiomyopathies and pacemakers have refined the recommendations. The detailed medical history and examination are crucial for differentiating between cardiac and noncardiac causes and determining the appropriate treatment. High-risk patients need urgent and comprehensive diagnostics. The basic diagnostics include medical history, physical examination and a12-lead electrocardiography (ECG). Further tests, such as long-term ECG monitoring, implantable loop recorders and electrophysiological investigations are helpful in unclear cases. The treatment depends on the cause, with pacemaker implantation and implantable cardioverter defibrillators (ICD) being important for cardiac causes, while behavioral measures and medication management have priority for noncardiac syncope.

Premature ventricular complexes: Assessing burden density in a large national cohort to better define optimal ECG monitoring duration

BackgroundPremature ventricular contraction (PVC) burden is a risk factor for heart failure and cardiovascular death in patients with structural heart disease. Long-term electrocardiographic monitoring can have a significant impact on PVC burden evaluation by further defining PVC distribution patterns. ObjectiveThis study aimed to ascertain the optimal duration of electrocardiographic monitoring to characterize PVC burden and to understand clinical characteristics associated with frequent PVCs and nonsustained ventricular tachycardia in a large US cohort. MethodsCommercial data (iRhythm’s Zio patch) from June 2011 to April 2022 were analyzed. Inclusion criteria were age >18 years, PVC burden ≥5%, and wear period ≥13 days. PVC burden cutoffs were determined on the basis of AHA/ACC/HRS guidelines for very frequent PVCs (10,000–20,000 during 24 hours). Patients were assigned to categories by PVC densities: low, <10%; moderate, 10% to <20%; and high, ≥20%. Mean measured error was assessed at baseline and daily until the wear period’s end for overall PVC burden and different PVC densities. ResultsAnalysis of 106,705 patch monitors revealed a study population with mean age of 70.6 ± 14.6 years (33.6% female). PVC burden was higher in male patients and those >65 years of age. PVC burden mean error decreased from 2.9% at 24 hours to 1.3% at 7 days and 0.7% at 10 days. Number of ventricular tachycardia episodes per patient increased with increasing PVC burden (P < .0001). ConclusionExtending ambulatory monitoring beyond 24 hours to 7 days or more improves accuracy of assessing PVC burden. Ventricular tachycardia frequency and duration vary by initial PVC density, highlighting the need for prolonged cardiac monitoring.

The effectiveness of atrial fibrillation identification using noninvasive long-term electrocardiographic monitoring system (NOMED-AF TECH).

Although it is well‑known that longer electrocardiographic (ECG) monitoring allows for detection of paroxysmal silent atrial fibrillation (SAF), it is still unknown how long the ECG monitoring should last to increase the probability of SAF diagnosis. Our aim was to analyze ECG acquisition parameters and timing to detect SAF during the Noninvasive Monitoring for Early Detection of Atrial Fibrillation study. The protocol assumed up to 30 days of ECG telemonitoring of each participant in order to reveal AF / atrial flutter (AFL) episodes lasting at least 30 seconds. SAF was defined as AF detected and confirmed by cardiologists in asymptomatic individuals. The ECG signal analysis was based on the results of 2974 participants (98.67%). AF/AFL episodes were registered and confirmed by cardiologists in 515 individuals, that is, 75.7% of all patients (n = 680) in whom AF/AFL diagnosis was established. The median monitoring time to detect the first SAF episode was 6 days (interquartile range [IQR], 1-13). Fifty percent of the patients with this type of arrhythmia were identified by 6th day (IQR, 1-13) of the monitoring, and 75% by the 13th day of the study. Paroxysmal AF was registered on average on 4th day (IQR, 1-10). The ECG monitoring time to detect the first episode of SAF in at least 75% of patients at risk of this arrhythmia was 14 days. Detection of 1 patient with de novo AF, SAF, or de novo SAF, required monitoring of, respectively, 17, 11, and 23 patients.

The Role of Advanced Echocardiographic Parameters of the Left Atrial Function in the Incidence of Cryptogenic Ischemic Stroke: A Review.

Stroke is one of the primary causes of morbidity and mortality worldwide, including a large proportion of cryptogenic strokes. Long-term electrocardiographic monitoring is beneficial in prospective studies for detecting atrial fibrillation in patients with cryptogenic stroke. This review aimed to evaluate the advanced echocardiographic parameters and their roles in assessing left atrial (LA) function in the incidence of cryptogenic and ischemic strokes. Main resources, including PubMed, Scopus, and ISI Web of Science databases, were evaluated for articles published in English from 2010 until May 2021. LA echocardiographic parameters such as LA strain and strain rate, isovolumetric relaxation time (IVRT), the mean left atrial volume index (LAVI), LA reservoir volume, systole strain rate (SSR) of left atrial appendage, and lack of LA function response to maximal exercise as measured by the LA ejection fraction during rest and exercise could be considered for assessing the risk of cryptogenic strokes and ischemic strokes. The results indicated that increased LA volumes and reduced LA strain rate were correlated with cryptogenic stroke. Advanced parameters of LA function, measured by speckle tracking echocardiography, such as strain and strain rate values in different parts of the cardiac cycle, in addition to standard measures of LA function such as LA ejection fraction and LAVI, will define an excellent understanding regarding LA myopathy and risk assessment of cryptogenic stroke, independent of considering conventional cardiovascular risk factors.

Embroidered textile electrodes for long-term ECG monitoring

Electrocardiography (ECG) monitoring is very important for the diagnosis and examination of heart-related diseases. Electrodes are the main components in monitoring and recording ECG signals. In this work, we have developed embroidered electrodes using two types of conductive yarns. ECG detection performance of the electrodes was measured at static and dynamic conditions and results were compared to standard Ag/AgCl electrodes. The electrodes were developed with three different dimensional areas to investigate the effect of the size on ECG acquisition performance. ECG signals collected from both the embroidered and standard Ag/AgCl electrodes have visible P, QRS, and T waveforms. Signals collected using large-size textile electrodes show better signal amplitude, which would reveal that the performance of the electrodes becomes improved with an increase in size. However, signals collect more artifacts dynamic conditions contain motion artifacts, indicating this aspect requires further improvement.

Parameters Of Myocardial Electrical Instability In Patients After Myocardial Infarction Comorbid With A Novel Coronavirus Infection (COVID-19)

Objective — This article aims to assess parameters of myocardial electrical instability and arrhythmic events in patients after myocardial infarction (MI), with and without ST-segment elevation, comorbid/noncomorbid with a novel coronavirus infection (COVID-19) using a long-term electrocardiographic (ECG) monitoring. Methods — The study included 64 subjects: 25 (39%) patients with MI comorbid with COVID-19 (MI+C group) and 39 (61%) patients with MI noncomorbid with a novel coronavirus infection (MI group). The mean age of patients was 54.3±6.8 years. A long-term ECG monitoring for 97.4 (95% CI 77.9-115.2) hours was performed with Astrocard®-Telemetry system (Meditek JSC, Russia), starting from the 4th day of MI. Rhythm and conduction disorders, along with ischemic episodes were recorded; an analysis of ventricular late potentials, heart rate turbulence, and QT dispersion was carried out. Results — There were no differences in the frequency of delayed afterdepolarizations in MI and MI+C groups: 15-28% and 18-33% of patients, respectively. An analysis of turbulence parameters did not reveal statistically significant differences between the groups. Such arrhythmic events as frequent supraventricular extrasystole and life-threatening arrhythmias (ventricular extrasystole of grade 4A and higher sensu B. Lown and M. Wolf) were recorded significantly more often in the MI+C group than in the MI group: 48% vs. 20.5% (p=0.021) and 24% vs. 5.1% (p=0.026), respectively. Conclusion — The novel coronavirus infection (COVID-19) exacerbates myocardial electrophysiological heterogeneity in the acute cardiovascular event and is associated with an increase in clinically significant arrhythmic events.

Multifunctional, breathable MXene-PU mesh electronic skin for wearable intelligent 12-lead ECG monitoring system

With the advent of an aging society and increasing concern for cardiovascular health, comfortable long-term electrocardiographic (ECG) monitoring systems in daily life are much in demand. If the system can give real-time feedback on cardiovascular status and offer timely personalized advice like doctors, it will be beneficial to promote cardiovascular health and alleviate the imbalance of medical resources. Herein, we report a multifunctional, conformal, and air-permeable electronic skin (e-skin) based on MXene-Polyurethane mesh (MPM). When used as ECG electrodes, the e-skin shows ultra-low electrode–skin contact impedance (4.68 kΩ at 1 kHz), high signal-to-noise ratio (16.5 dB), and high breathability (2.1838 kg/m2/day), and can be continuously worn for at least 7 days. As a strain sensor, the e-skin exhibits a large measurement range (>40 %) and unique segmental sensitivity (GF = 172.54 in 0 ∼ 18.64 % and 79.38 in 18.64 ∼ 50 %), which is suitable for detecting both subtle and large physiological signals. More significantly, by combining the MPM e-skin with a flexible printed circuit board (FPCB) and a merged convolutional neural network & long-short-term memory (CNN & LSTM) intelligent algorithm, the acquired wearable intelligent e-skin system can realize daily 12-hour 12-lead ECG monitoring with diagnostic accuracy over 99 % for four arrhythmias. These results show that the MPM e-skin has huge potential in multifunctional intelligent healthcare systems. In particular, an intelligent ECG system similar to a “daily doctor” is proposed for daily long-term cardiovascular health monitoring.

Improving public health using contactless ECG electrodes for long-term monitoring of arrhythmia

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide, resulting in 17.3 million deaths annually. Thus, any CVD symptoms should be immediately diagnosed for effective treatments [1]. In this case, Electrocardiography (ECG) is widely considered for monitoring and diagnosing heart symptoms. The traditional wet Ag/AgCl electrodes can acquire high-quality ECG signals. However, they cause skin irritation and require careful skin preparation by a specialist. Therefore, they are not practical for efficient long-term ECG monitoring. To overcome these limitations, contactless capacitive electrodes are introduced as an alternative. But these electrodes suffer various shortfalls in collecting high-quality and clinically acceptable signals. As a coupling capacitor between the body and electrode is formed in these sensors and this capacitor changes due to the subject’s physiological or body movements leading to Motion Artifacts (MAs). In addition, the variable skin potential across the capacitor forms an additive voltage that may distort the ECG signal adversely. This presentation aims to illustrate a comprehensive literature review and methodology used in my study. Regarding the methodology, I intend to simulate the equivalent model of the measurement system and implement it in the real world. Moreover, two issues will be addressed in my research questions. Firstly, I will extract the variable impedance between the sensor and the subject’s skin, which has the highest correlation with MAs according to literature, by injecting a voltage with a known frequency into the circuit. Unlike many previous methods, the ECG signal, and impedance signal will be measured simultaneously. I will address the optimal frequency and impedance signal with maximum correlation with MAs, which are the gaps in previous works. Secondly, in past studies, the effects of skin potential on MAs have not been sufficiently investigated, which is aimed to be analyzed, estimated, and subtracted from the polluted ECG noise signal.

Armband Sensors Location Assessment for Left Arm-ECG Bipolar Leads Waveform Components Discovery Tendencies around the MUAC Line.

Sudden cardiac death (SCD) risk can be reduced by early detection of short-lived and transient cardiac arrhythmias using long-term electrocardiographic (ECG) monitoring. Early detection of ventricular arrhythmias can reduce the risk of SCD by allowing appropriate interventions. Long-term continuous ECG monitoring, using a non-invasive armband-based wearable device is an appealing solution for detecting early heart rhythm abnormalities. However, there is a paucity of understanding on the number and best bipolar ECG electrode pairs axial orientation around the left mid-upper arm circumference (MUAC) for such devices. This study addresses the question on the best axial orientation of ECG bipolar electrode pairs around the left MUAC in non-invasive armband-based wearable devices, for the early detection of heart rhythm abnormalities. A total of 18 subjects with almost same BMI values in the WASTCArD arm-ECG database were selected to assess arm-ECG bipolar leads quality using proposed metrics of relative (normalized) signal strength measurement, arm-ECG detection performance of the main ECG waveform event component (QRS) and heart-rate variability (HRV) in six derived bipolar arm ECG-lead sensor pairs around the armband circumference, having regularly spaced axis angles (at 30° steps) orientation. The analysis revealed that the angular range from −30° to +30°of arm-lead sensors pair axis orientation around the arm, including the 0° axis (which is co-planar to chest plane), provided the best orientation on the arm for reasonably good QRS detection; presenting the highest sensitivity (Se) median value of 93.3%, precision PPV median value at 99.6%; HRV RMS correlation (p) of 0.97 and coefficient of determination (R2) of 0.95 with HRV gold standard values measured in the standard Lead-I ECG.

Flexible Hybrid Electronics Nanofiber Electrodes with Excellent Stretchability and Highly Stable Electrical Conductivity for Smart Clothing.

In this paper, a side-by-side, dual-nozzle electrospinning process was used to prepare a flexible hybrid electronics (FHE) material with excellent stretchable properties. A highly stable electrical conductivity was also imparted to the resulting membrane electrodes using silver nanoparticles (AgNPs) and carbon-based nanomaterials of different structures. The AgNP/carbon-based nanomaterials were coated onto bicomponent polymer nanofibers (composed of polyurethane (PU) and polyvinylidene difluoride (PVDF)) on the nanofiber membrane. The FHE nanofiber electrodes were finally integrated into clothing designed to accurately measure human body sensing signals (e.g., electrocardiography (ECG) and electromyography (EMG) signals). To effectively increase the high electrical conductivity, a polymer-type dispersant (polyisobutylene-b-poly(oxyethylene)-b-polyisobutylene, a triblock copolymer) was used to effectively and stably disperse AgNPs with different particle sizes and carbon-based nanomaterials with different geometric dimensions (e.g., zero-dimensional carbon black, one-dimensional carbon nanotubes, and two-dimensional graphene) through non-covalent adsorption. Moreover, the bicomponent PVDF-PU nanofibers were immersed in a mixed dispersant of AgNPs and carbon-based nanomaterials at low concentrations, and thermal post-treatment was conducted to improve the electrical conductivity. The AgNP/graphene oxide (GO) nanofiber electrode exhibited a continuous phase with a stable material microstructure after 5000 repetitions of 50% tension-tension fatigue testing. The waveform pattern obtained from the proposed AgNP/GO nanofiber electrode was compared with those of traditional ECG and EMG electrodes. The nanofiber web electrode treated with organic/inorganic mixed dispersants and verified via tests of its electrical and fatigue properties was found to be suitable for long-term ECG and EMG monitoring, and it has excellent potential in wearable smart sensors.

Paroxysmal Atrial Fibrillation in Horses: Pathophysiology, Diagnostics and Clinical Aspects.

Simple SummaryAtrial fibrillation is the most common pathological cardiac arrhythmia affecting performance in horses. The sporadic form of atrial fibrillation, termed paroxysmal atrial fibrillation, spontaneously cardioverts to normal sinus rhythm usually within 7 days. The condition may go undetected, as episodes can occur intermittently at different frequencies and vary in duration from minutes to hours. However, paroxysmal atrial fibrillation may still result in poor performance, especially in racehorses, resulting in possible negative consequences for the horses and their owners. The epidemiology and pathophysiology of the disease are not well described. We investigate the current knowledge and present possible risk factors that may predispose horses to paroxysmal atrial fibrillation. Early diagnosis is crucial, which is why current and future diagnostic modalities are discussed.Atrial fibrillation (AF) is the most common arrhythmia in horses causing poor performance. As in humans, the condition can be intermittent in nature, known as paroxysmal atrial fibrillation (pAF). This review covers the literature relating to pAF in horses and includes references to the human literature to compare pathophysiology, clinical presentation, diagnostic tools and treatment. The arrhythmia is diagnosed by auscultation and electrocardiography (ECG), and clinical signs can vary from sudden loss of racing performance to reduced fitness or no signs at all. If left untreated, pAF may promote electrical, functional and structural remodeling of the myocardium, thus creating a substrate that is able to maintain the arrhythmia, which over time may progress into permanent AF. Long-term ECG monitoring is essential for diagnosing the condition and fully understanding the duration and frequency of pAF episodes. The potential to adapt human cardiac monitoring systems and computational ECG analysis is therefore of interest and may benefit future diagnostic tools in equine medicine.

Seven day continuous ambulatory electrocardiographic telemetric study with pocket electrocardiographic recording device for detecting hydroxychloroquine induced arrhythmias.

Objective:The use of hydroxychloroquine (HCQ) for COVID-19 treatment and prophylaxis raised issues concerning its cardiac safety owing to the possibility of QT prolongation and arrhythmias. There was no study on long-term electrocardiographic telemetry monitoring of patients taking HCQ. We planned a continuous electrocardiographic Holter telemetry of these patients for 7 days.Material and Methods:Health care workers taking HCQ as pre exposure prophylaxis and patients on HCQ were monitored using seven day Holter electrocardiographic telemetry with continuous beat to beat analysis. Telemetry can instantly convey any arrhythmic event or significant QT prolongation to the medical faculty.Results:Twenty-five participants with a mean age of 42.4 ± 14.1 years were included in the study; 40% were females. Twenty percent of participants needed to stop HCQ. Four patients developed QT prolongation >500 ms and needed to stop HCQ, one patient had accelerated idioventricular rhythm and stopped treatment, and one had short episodes of atrial fibrillation. No malignant arrhythmia or ventricular arrhythmia, or torsade de pointis were noted. No episode of significant conduction disturbance and arrhythmic death was noted. Baseline mean QTc was 423.96 ± 32.18 ms, mean QTc corrected at 24 h was 438.93 ± 37.95, mean QTc was 451.879 ± 37.99 at 48 h, and change in baseline mean QTc to max QTc was 30.74 ± 21.75 ms at 48 h. All those who developed QTc prolongation >500 ms were greater than 50 years of age.Conclusion:Ambulatory telemetry ECG monitoring detects early QT prolongation, and stopping drugs prevents malignant arrhythmias. HCQ seems to have less risk of QT prolongation in young, healthy individuals.

Changing patterns of use of implantable cardiac monitors from 2011 to 2018 for a large commercially-insured U.S. population.

Implantable cardiac monitors (ICMs) provide long-term electrocardiographic monitoring for a number of indications. However, frequencies of use by indication and temporal changes have not been characterized on a national scale. We sought to characterize overall use and changes between 2011 and 2018. We used generalized linear models to characterize the incidence rate per 1,000,000 patient-quarters at risk and an autoregressive integrated moving average model to account for autocorrelation in this time series data. We studied commercially-insured patients and their insured dependents in the IBM MarketScan Commercial Database who had an ICM placed. We described the characteristics of individuals who received ICMs and the frequency of placements into 3 guideline concordance groups. We estimated the mean change per quarter in ICM placements (mean quarterly change in incidence rate per 1,000,000 patient-quarters at risk) for quarter (Q)1 2011 through Q1 2014, Q1 2014 to Q2 2014, and Q2 2014 through Q4 2018 for each guideline concordance group. The most common indications for categorizable ICM placement were syncope (24%), atrial fibrillation (11%), and stroke (11%). For each of the 3 guideline concordance groups except guideline unaddressed inpatient ICM placements, there was a significant increase in use either during the Q1 2014 to Q2 2014 or the Q2 2014 through Q4 2018 periods. A significant portion of ICM placements were for indications that lack strong evidence, such as established atrial fibrillation. The incidence of ICM placement for most of the indications and settings increased after miniaturization and technical improvements.

Flexible silver nanowire dry electrodes for long-term electrocardiographic monitoring

Flexible silver nanowire dry electrodes for long-term electrocardiographic monitoring

Evaluation of dry textile electrodes for long-term electrocardiographic monitoring

BackgroundContinuous long-term electrocardiography monitoring has been increasingly recognized for early diagnosis and management of different types of cardiovascular diseases. To find an alternative to Ag/AgCl gel electrodes that are improper for this application scenario, many efforts have been undertaken to develop novel flexible dry textile electrodes integrated into the everyday garments. With significant progresses made to address the potential issues (e.g., low signal-to-noise ratio, high skin–electrode impedance, motion artifact, and low durability), the lack of standard evaluation procedure hinders the further development of dry electrodes (mainly the design and optimization).ResultsA standard testing procedure and framework for skin–electrode impedance measurement is demonstrated for the development of novel dry textile electrodes. Different representative electrode materials have been screen-printed on textile substrates. To verify the performance of dry textile electrodes, impedance measurements are conducted on an agar skin model using a universal setup with consistent frequency and pressure. In addition, they are demonstrated for ECG signals acquisition, in comparison to those obtained using conventional gel electrodes.ConclusionsDry textile electrodes demonstrated similar impedance when in raised or flat structures. The tested pressure variations had an insignificant impact on electrode impedance. Looking at the effect of impedance on ECG signals, a noticeable effect on ECG signal performance metrics was not observed. Therefore, it is suggested that impedance alone is possibly not the primary indicator of signal quality. As well, the developed methods can also serve as useful guidelines for future textile dry-electrode design and testing for practical ECG monitoring applications.

Длительный электрокардиографический мониторинг в кардиохирургическом стационаре: современные взгляды и опыт применения телемониторинговой системы после стентирования коронарных артерий

Актуальность. Заболевания сердечно-сосудистой системы в Украине занимают лидерские позиции. На сего­дняшний день постоянный мониторинг электрокардиограммы (ЭКГ) является рутинным исследованием у пациентов, которые госпитализируются в больницу с сердечно-сосудистой патологией. Цель: провести анализ опыта применения длительного электрокардиографического мониторинга у пациентов в раннем послеоперационном периоде стентирования коронарных артерий. Материалы и методы. В исследование были включены 24 пациента с ишемической болезнью сердца, которым было проведено стентирование коронарных артерий в плановом порядке. Всем пациентам после окончания оперативного вмешательства проводился длительный ЭКГ-мониторинг. Результаты. Среди пациентов, принимавших участие в нашем исследовании, у 17 % больных в раннем послеоперационном периоде отмечались единичные наджелудочковые экстрасистолы и у всех пациентов были зафиксированы эпизоды единичных желудочковых экстрасистол. Значимой дислокации сегмента ST не было зафиксировано ни у одного пациента. Выводы. На основе наблюдения за пациентами с сердечно-сосудистыми событиями в послеоперационном периоде показано, что использование круглосуточной автоматической записи ЭГК с помощью мобильных устройств улучшает возможности своевременной диагностики (включая ургентную) повторных событий. Сформулированы рекомендации о целесообразности ее использования в различных режимах для пациентов с разным течением болезни.

External Cardiac Loop Recorders: Functionalities, Diagnostic Efficacy, Challenges and Opportunities.

According to the World Health Organization's (WHO) report of 2016, cardiovascular diseases (CVDs) accounted for mortality of an estimated 17.9 million people globally. Of these deaths, 85% were due to myocardial infarction and stroke. Further, the pre-dominant atrial fibrillation (AF) arrhythmia has been the most suspected underlying cause of transient ischemic attack or stroke. Thus, the etiologies of early symptoms like syncope and palpitations in patients needs to be evaluated by employing proper diagnostic tests to make early treatment decisions. The most widely referred 24 to 48 hour Holter electrocardiographic (ECG) monitoring tests have not been proved to be much effective in recognizing infrequent intermittent arrhythmic episodes. These drawbacks have led to the development of long-term ambulatory ECG (AECG) monitoring devices. This review reports the state-of-the-art existing AECG monitoring devices and their role of long-term ECG recording in patients suspected with cardiac syncope and palpitations to understand the underlying arrhythmic cause, as well as in the diagnosis and management of AF. Primarily, the utility and diagnostic yield of external cardiac recorders or event loop recorders (ELRs) in capturing the symptom-rhythm correlation which constitutes a clinically useful recordings of heart's electrical activity during infrequent arrhythmic conditions was critically reviewed. Furthermore, a brief case study on challenges involved in clinical data acquisition at a cardiac care unit using ambulatory external monitoring device has been presented. Finally, improvements in design engineering and algorithmic developments to enhance the diagnostic yield and usability of ELRs in clinical settings have been proposed.

Development of Washable Silver Printed Textile Electrodes for Long-Term ECG Monitoring.

Long-term electrocardiography (ECG) monitoring is very essential for the early detection and treatment of cardiovascular disorders. However, commercially used silver/silver chloride (Ag/AgCl) electrodes have drawbacks, and these become more obvious during long-term signal monitoring, making them inconvenient for this use. In this study, we developed silver printed textile electrodes from knitted cotton and polyester fabric for ECG monitoring. The surface resistance of printed electrodes was 1.64 Ω/sq for cotton and 1.78 Ω/sq for polyester electrodes. The ECG detection performance of the electrodes was studied by placing three electrodes around the wrist where the electrodes were embedded on an elastic strap with Velcro. The ECG signals collected using textile electrodes had a comparable waveform to those acquired using standard Ag/AgCl electrodes with a signal to noise ratio (SNR) of 33.10, 30.17, and 33.52 dB for signals collected from cotton, polyester, and Ag/AgCl electrodes, respectively. The signal quality increased as the tightness of the elastic strap increased. Signals acquired at 15 mmHg pressure level with the textile electrodes provided a similar quality to those acquired using standard electrodes. Interestingly, the textile electrodes gave acceptable signal quality even after ten washing cycles.

Incidence, duration, pattern, and burden of de novo atrial arrhythmias detected by continuous ECG monitoring using an implantable loop recorder following ablation of the cavotricuspid isthmus

BackgroundFollowing cavotricuspid isthmus (CTI) ablation, many patients with atrial flutter (AFL) are diagnosed with atrial fibrillation (AF). The incidence, duration, pattern, and burden of AF remain undefined. These may have implications for the management of these patients.ObjectiveTo classify the incidence, duration, pattern, and burden of AF/AFL using an implantable loop recorder (ILR) after CTI ablation.MethodsWe enrolled consecutive patients with CTI-dependent AFL, no known history of AF, and CHA2DS2-VASc ≥ 2. An ILR was implanted before or within 90 days of ablation. The time to first AF/AFL, pattern, duration, and burden of longest AF/AFL were determined. Five distinct AF/AFL cohorts were identified: no AF/AFL and those with recurrences of isolated, clustered, frequent, or persistent AF/AFL.ResultsFifty-two patients (81% male; 73 ± 9 years; CHA2DS2-VASc 3.7 ± 1.2) were followed for 784 (interquartile range [IQR] 263, 1150) days. AF/AFL occurred in 44 (85%) patients at 64 (IQR 8, 189) days post-CTI ablation and was paroxysmal in 31 (70%) patients (burden 0.6% [IQR 0.1, 4.8]). AF/AFL was isolated (n = 5, 11%), clustered (n =7, 16%), frequent (n =19, 43%), and persistent (n =13, 30%). The longest AF episode was <24 hours in 27 (61%) patients.ConclusionFollowing CTI ablation in AFL patients, although AF/AFL occurs in most patients, the burden is low and episodes were <24 hours in the majority of patients. Additional studies are needed to determine whether long-term electrocardiographic monitoring can help guide management of patients undergoing CTI ablation.

The association of long-term air pollution exposure with supraventricular arrhythmia and atrial fibrillation in the Multi-Ethnic Study of Atherosclerosis

Background/Aim: Air pollution is an important contributor to cardiovascular morbidity and mortality. Acute exposure to O3 and PM2.5 is associated with episodes of atrial fibrillation (AF), and NO2 exposure is associated with same-day hospitalization for ventricular and supraventricular arrhythmias. Studies investigating longer-term exposures on AF risk have shown mixed results and additional work clarifying the role of pollutants on atrial electrophysiology is needed. This analysis used long-term individual-level ambient pollutant exposure and two-week ambulatory electrocardiographic (ECG) monitoring to investigate the association between pollutants and atrial arrhythmias.Methods: In the Multi-Ethnic Study of Atherosclerosis (MESA), we used estimated five-year average ambient PM2.5, NOX, and O3 from validated hierarchical spatio-temporal models, and conducted two-week ambulatory ECG monitoring of participants. Supraventricular arrhythmia measures of interest were presence of AF during monitoring, average count of premature atrial contractions (PACs) per hour, and average runs per day of supraventricular tachycardia (SVT). Generalized estimating equations were used to account for multiple exposure and outcome measurements in individual participants, adjusting for MESA study site and other a priori defined potential confounders. Secondary analyses explored two-week exposure windows.Results: In 1,324 participants, average age 74 years, five-year average ambient PM2.5, NOX, and O3 levels were not significantly associated with AF, PACs, or SVT. In secondary analyses of two-week exposures, higher PM2.5 was associated with greater runs of SVT, higher O3 with greater odds of AF, and higher NOX with lower odds of AF.Conclusions: Using recently developed study-specific exposure estimation and long-term ECG monitoring, we found no evidence that five-year average exposure to PM2.5, NOX, and O3 was associated with supraventricular arrhythmias. Secondary analyses using two-week exposures suggested moderate associations, but given multiple testing, these associations may have arisen by chance. Additional work is needed to further investigate the relationship of long-term pollution with supraventricular arrhythmias.