Continuous ECG Research Articles

Healthy Young POLes – HYPOL database with synchronised beat-to-beat heart rate and blood pressure signals

Data sharing in medical research entails making research data available to other researchers for review, re-use, and collaboration purposes. This paper seeks to describe the HYPOL (Healthy Young POLes) database, which has been prepared for sharing. This database houses the clinical characteristics and beat-to-beat cardiovascular time series of 278 individuals of Polish descent, all aged between 19 and 30 years. The data were collected from healthy volunteers who participated in multiple projects carried out at the Department of Cardiology-Intensive Therapy research laboratory, Poznan University of Medical Sciences, Poznan, Poland. The cardiovascular time series data was obtained from non-invasive continuous finger blood pressure and ECG recordings, with sessions lasting up to 45 minutes. The HYPOL database includes an xls file detailing the main clinical characteristics and text files that capture ECG-derived RR intervals, finger systolic, diastolic, and mean blood pressure values, as well as the duration of interbeat intervals. There are data from 149 women (53.6% of the total) and 129 men. The median age of all participants studied is 24 years, their BMI was <24 kg/m2, pulse rate and blood pressure were normal. The median duration of the recordings was almost 30 minutes. In addition, we summarise selected parameters of heart rate variability (HRV) and heart rate asymmetry (HRA). The HYPOL database is available at hypol.ump.edu.pl. The download of data is free of charge after simple registration. Researchers and engineers can use the database for their purposes, except for selling it. The data can be used for testing various mathematical algorithms for HRV, HRA, blood pressure variability and asymmetry, and baroflex function.

Evaluation and application of treadmill Cardiopulmonary Exercise Testing and field measurement results of female national team water polo players

Abstract Introduction Due to intensive sport adaptation, examinations of elite athletes are a special entity of cardiology. Cardiovascular follow-up of elite athletes is a significant method of supporting safe and successful sport. In many sports like water polo, training work takes place in different environments and with different forms of movement, then the tests applied in laboratory circumstances. Although treadmill cardiopulmonary exercise testing (CPET) is widely used in cardiology screening, we have little information of its usefulness in physical fitness follow-up in non-running sports. Purpose We aimed to analyze and to compare the data of elite youth team (YT) and adult water polo players collected from maximal intensity cardio-pulmonary exercise testing (CPET) and field examinations in definition of current fitness status of the different age groups. Methods During the age- and sport specific field measurements (swimming tests) and CPET examinations, we collected resting and exercise heart rate data and lactate levels at defined time points. During CPET, continuous 12-lead ECG, gas analysis and repeated blood pressure measurements were also carried out. Results 46 female water polo players were examined (age: 18.5±5.9y, adults: 19, training: 18.0±7.9h/w). Comparing CPET and field measurements, no differences were found between resting heart rate (75.7±13.4vs73.1±13.0 BPM, p=0.22) and resting lactate levels (1.5±0.4vs1.6±0.6 mM, p=0.29). Achieved maximal heart rates were higher during CPET examinations, than during field tests (196.3±9.7 vs 191.0±12.5 BPM, p=0.001) On the contrary, maximal lactate levels were lower during CPET in comparison to field measurements (8.4±2.4 vs 9.6±2.7 mM, p=0.01). Lactate levels stayed high after routine cool-down swimming ordered by the trainers, but decreased after suggested further training (6.6±2.7 vs 3.7±1.6 mM, p=10-16). When comparing the age groups, CPET examinations showed similar relative maximal aerobic capacity (44.4±4.8vs44.9±5.5 ml/kg/min, p=0.72) and peak lactate values (8.2±2.7vs8.7±1.9 mM, p=0.48), while maximal heart rates were higher in YT groups (200.7±7.2 vs 190.1±9.6 BPM, p<0.001) as compared to adults. Similarly, maximal lactate levels showed no differences (9.1±2.6 vs 10.4±2,7 mM, p=0.13), while maximal heart rates were higher in YT groups (197.7±10.0 vs 181.4±8.9 BPM, p<0.001) as compared to adults during field examinations. Conclusions Although field measurements and laboratory CPET results differ from several points of view, differences between age groups and the kinetics of the data are similar. Maximal heart rates are easier to achieve during CPET, while more intensive lactate increase could be observed during field measurements. Combining the above examinations helps defining maximal physiological values, fitness status, differences between different age groups, and optimizing training plans, as well as differentiating between physiological and pathological sport adaptation.

Quiescent-yet-excitable pluripotent stem cell-derived cardiomyocytes engraft without fatal arrhythmias in minipig and primates

Abstract Background Pluripotent stem cell-derived cardiomyocyte (PSC-CM) transplantation is a promising therapy for subacute myocardial infarction (MI), but transient engraftment-related arrhythmia (EA) is major barrier to clinical development (1, 2). We hypothesize that PSC-CM genetically edited to remove automaticity but otherwise functionally intact will engraft in vivo with greater arrhythmic safety. Methods Combinatorial CRISPR/Cas9 genome editing to screen for electrically quiescent PSC-CM yielded a line deficient in the depolarization-associated genes HCN4, CACNA1H, and SLC8A1, combined with overexpression of the hyperpolarization-associated gene KCNJ2. Initially, we transplanted 150 million (n=3) and 500 million gene-edited (n=2) and 150 million wildtype (n=7) PSC-CMs into a minipig model of EA, and we monitored the animals for up to seven weeks on continuous ECG for arrythmia without anti-arrhythmic therapy. In a second study, we transplanted 750 million gene-edited (n=2) and wildtype (n=1) PSC-CMs into sub-acutely infarcted Macaca nemestrina primates. Sham transplant (n=1) was also performed, and all animals were observed for up to three months with immunosuppression and beta-blocker/amiodarone therapy. Results Gene-edited PSC-CM successfully engrafted and structurally coupled with the host myocardium of minipigs (Figure 1) and nonhuman primates (Figure 2). No significant EA occurred after transplanting edited PSC-CM at the 150 million dose, whereas brief EA (<24 hours) was observed and well tolerated at the higher 500 million dose. All five minipigs survived to prespecified timepoints without complication. Conversely, wildtype PSC-CM controls demonstrated uncontrolled and fatal ventricular tachycardia (VT). Of the seven WT control minipigs, only four survived (43% mortality); three expired or were euthanized due to unstable VT or ventricular fibrillation. Arrythmia burden for both 150 and 500 million doses were significantly reduced compared to the 150 million wildtype dose in the first 30-days post-transplant (p<0.0001 for both). We then tested edited PSC-CM in a clinically relevant nonhuman primate model of sub-acute myocardial infarction using standard medical therapy including modest antiarrhythmic therapy. No arrythmia was noted in both nonhuman primates dosed with 750 million edited PSC-CM whereas significant arrhythmia was observed with wildtype despite beta blocker and amiodarone therapy. All pig and primate grafts were structurally coupled with host myocardium. Conclusion Genetically-edited PSC-CM without pacemaker-like activity significantly reduced arrythmia burden and prevented arrhythmic death in a dose-escalation study in minipig. No arrhythmia was observed in a clinically relevant nonhuman primate model of cardiac remuscularization for sub-acute myocardial infarction. This study supports continued investigation of this novel strategy to improve safety and tolerability of PSC-CM transplantation.Edited PSC-CM transplant in minipigEdited PSC-CM transplant in primates

Initial clinical experience with new technology: ePatch extended Holter monitoring

Abstract Introduction Holter monitor electrocardiography is used to detect potential cardiac arrhythmias such as atrial fibrillation (AF). However, conventional ECG monitoring, data analysis and reporting methods can be labor-intensive and inefficient, leading to high upfront costs and long turnaround times. At the same time, traditional Holter devices can be cumbersome to wear, while inconvenient processes may reduce patient compliance and satisfaction – which impacts diagnostic yield. This new device (ePatch®) is a simple patch application, enrollment and activation with no battery charging needed and no cable attachments (Figure 1). Up to 14 days of continuous ECG recording. Wearable in shower, during exercise and while sleeping. Single-channel, up to 14 days. Two-channel, up to 5 days Purpose Our goal is to evaluate the quality and diagnostic efficacy of ePatch® in different clinical settings. Methods Prospective study of patients with ePatch® placed in our center requested for study of undocumented palpitations, syncope or cryptogenic stroke. Clinical variables, diagnostic accuracy, and time to diagnostic event are analyzed. Results We enrolled the first 57 patients, of whom 27 (50%) were women, with a mean age of 67.8 years (range 27 to 89). The most common indication was undocumented palpitations (35.1%) and cryptogenic stroke (35.1%), followed by syncope (29.6%). All the patients had correct compliance, tolerance and the ECG monitored was of good quality. A conclusive diagnosis: (symptomatic sustained tachyarrhythmia, atrial-ventricular block with bradyarrhythmia, significant pauses or AF) was obtained in 5 patients (8.7% of the total). The average event time since ePatch registration started was 2.4 days (range 1 to 5 days). Conclusions The ePatch® is a new extended Holter device offering a simple, complete and efficient ECG monitoring system. This new technology is safe and has numerous advantages: spend less time on logistics and device handling, prepare your patients efficiently, eliminate the need for additional consumables and constant battery replacement. The ECG monitor of our study is of 5 days, but it can be used for up to 14 days. It is designed to address the challenges of traditional Holter monitoring.

A digital health solution for long-term cardiac monitoring supporting a value-based stroke care path

Abstract Introduction Long-term continuous cardiac monitoring in high-risk populations increases the chances of detecting atrial fibrillation and related arrhythmias[1]. In-hospital ECG monitoring is usually too brief to detect cardiac risk factors, while the availability and usability of ambulatory ECG is often lacking. Digital health tools are an attractive option for user-friendly, accurate, scalable mid-to-long-term cardiac risk monitoring[2]. These tools can also act as a driver to organize personalized care around the patient but that requires innovation in the reimbursement system. Recently Belgium established the mHealthBelgium validation pyramid[3], a 3-stage framework for reimbursement of digital health tools. Methods We used our remote monitoring platform to build a digital health solution for cardiac monitoring that provides direct diagnostic value and supports the care path for patients with cryptogenic stroke or transient ischemic attack. Our CE-certified solution has a cardiac chest patch to record ECG and motion data and a docking station at the patient’s home to securely send data to the cloud where data analytics is done. Our annotation flow detects atrial fibrillation and other stroke-relevant risk factors, reducing data burden for healthcare providers (HCP). HCPs interact with the raw and annotated data through a dashboard that generates reports and integrates with medical record systems. On-demand logistics allows hospitals to monitor as many patients as needed without delay and a pay-per-use model allows flexible monitoring periods and obviates the need for up-front device purchase. Results Since January 2022, more than 529 patients have been monitored with a median recording duration of 14 days±12 days. Approximately 205,500 hours of continuous ECG data was collected and 13421 potential risk factors were annotated, including 7227 potential atrial events (fibrillation or flutter) in 374 patients (>70%). In 45% of cases (n = 242), one or more events were confirmed by HCPs as clinically relevant. Our solution has progressed through the first two stages of the mHealth system by demonstrating CE-certification and interoperability with the government eHealth platform. For the final stage (M3), we have submitted one of the first dossiers in Belgium for improving the stroke care path with a more fit-for-purpose technology and coupling reimbursement to this specific use case instead of fee-for-service coding. Our proposal includes a real-world outcome data study. Conclusion We validate the importance and utility of remote monitoring of cardiac risk factors within the stroke care path. Retrospective results show that in 45% of cases, clinically relevant events were detected indicating that meaningful remote patient data is compatible with HCP workflows. The solution is progressing through a new care path-based reimbursement system that serves as a model for organizing value-based care around the patient's needs.Care path with remote patient monitoringReduced time to diagnosis with RPM

Deep inspiration electrocardiogram test: physiologic mechanisms and diagnostic capabilities

The article reflects modern concepts about the effect of deep inspiration and breath holding on the heart functioning and the reflection of these processes at ECGs. Positional changes of Q waves, primarily in leads III and aVF, and their possible differences from pathological Q waves are described. Reflex and humoral effects of deep inspiration and breath holding on heart functions such as contractility, automatism and conductivity are considered. Examples of rhythm and conduction disturbances that rarely occur during breath holding are illutrated on ECGs. A recommended variant of the implementation of the deep inspiration ECG test using computer ECG systems is described, which implements continuous ECG recording on free breathing, during inspiration and while holding the breath. This version of the test does not change the operators’ complexity and time of ECG registration.

Abstract 13943: Comparison of the Frequency and Time to True Ventricular Tachycardia Among Patients in the Cardiac, Medical/Surgical and Neurologic Intensive Care Units

Introduction: Continuous ECG monitoring is the non-invasive gold standard used to identify ventricular tachycardia (VT), yet 87% of current bedside monitor VTs could be false. Therefore, knowing the burden of true VT is essential to guide treatment to those at greatest risk of poor outcomes. Hypothesis: When stratifying by intensive care unit (ICU) (cardiac, medical/surgical, neurological), there will be differences in: 1) demographic and clinical characteristics of patients with true VT; and 2) frequency and time to first true VT. Methods: Retrospective cohort study of adults admitted to an academic medical center ICU, 9/13-4/15. Potential VTs among 5,679 consecutive ICU patients were manually annotated by clinicians as true/false. Patient-level data were extracted from the health record. We used Kaplan-Meier and Cox proportional hazards methods to calculate time to first true VT and 60-day VT rate by ICU type. Results: There were differences in all characteristics examined (p<0.0001)(Table) and frequency of true VT, stratified by ICU type (log-rank p<0.0001)(Figure). After adjustment for age, gender, and risk factors (Table), CICU patients had a 42% increased rate (HR 1.42, 95% CI 1.16-1.74) and NICU patients had a 28% decreased rate of VT (HR 0.72, 95% CI 0.59-0.89) compared to M/SICU patients. Conclusion: Patients in the CICU experienced true VT much earlier (1.5 days) after admission than patients in the M/SICU and NICU. In addition, CICU patients had a higher rate of true VT and associated VT risk factors as compared to M/SICU and NICU patients. As expected, known cardiac risk factors are associated with true VT, but may be hidden among false alarms during bedside monitoring.

Multicentre, national, investigator-initiated, randomised, parallel-group, register-based superiority trial to compare extended ECG monitoring versus standard ECG monitoring in elderly patients with ischaemic stroke or transient ischaemic attack and the effect on stroke, death and intracerebral bleeding: the AF SPICE protocol

IntroductionAtrial fibrillation (AF) is a major risk factor for ischaemic stroke and transient ischaemic attack (TIA), and AF detection can be challenged by asymptomatic and paroxysmal presentation. Long-term ECG monitoring...

Complete Right Bundle Branch Block in Acute Coronary Syndrome with ST Segment Elevation: Epidemiological Features

Background: Complete right bundle branch in acute coronary syndrome with ST segment elevation is common and may predict a poor clinical prognosis. Its incidence has been the subject of several international studies, as well as, its related mortality, but its epidemiological data is lacking in Algeria. Aims: The main objective of our study is the determination of the frequency of complete right bundle branch block in acute coronary syndrome with ST segment elevation, the secondary objective was the analysis of its predictive factors and related mortality. Methods and materials: In this prospective study, conducted in the cardiology department of Hussein Dey hospital (Algiers-Algeria), 467 patients with acute coronary syndrome with elevated ST segment (87 women and 380 men) were enrolled between 28 February 2014 and 16 July 2015. The average age is 60 ± 13 years; at admission, a Holter recorder was attached for continuous ECG monitoring during 48 hours. Kruskal’s ANNOVA or H tests were used for comparison of quantitative variables, χ2 test or Fisher’s exact test, were used for qualitative variables, all tests were performed with 1st species risk of 5%. Results: The frequency of complete right bundle brunch block is 10.9 % (51 patients), CI 95%: [8.1%-13.7%], multivariate analysis identified the following independent predictors: anterior acute coronary syndrome, persistence of chest pain after thrombolysis, and diabetes type 2. The risk of mortality expressed by Hazard Ration (HR) is 3.4, CI95%: [1.07-11.35], p = 0.037; persistence of ST segment elevation after thrombolysis is the only predictive factor of mortality, identified in our study. Conclusion: Complete right bundle brunch block is frequent in acute coronary syndrome with elevated ST segment, its predictive factors according to our study are: anterior acute coronary syndrome, persistence of chest pain after thrombolysis, and type 2 diabetes. Its occurrence increases the risk of in-hospital mortality, and the predictor of this latter is the failure of thrombolysis.

Low-Power Long-Term Ambulatory Electrocardiography Monitor of Three Leads with Beat-to-Beat Heart Rate Measurement in Real Time.

A low-power long-term ambulatory ECG monitor was developed for the acquisition, storage and processing of three simultaneous leads DI, aVF and V2 with a beat-to-beat heart rate measurement in real time. It provides long-term continuous ECG recordings until 84 h. The monitor uses a QRS complex detection algorithm based on the continuous wavelet transform with splines, which automatically selects the scale for the analysis of ECG records with different sampling frequencies. It includes a lead-off detection to continuously monitor the electrode connections and a real-time system of visual and acoustic alarms to alert users of abnormal conditions in its operation. The monitor presented is based in an ADS1294 analogue front end with four channels, 24-bit analog-to-digital converters and programmable gain amplifiers, a low-power dual-core ESP32 microcontroller, a microSD memory for data storage in a range of 4 GB to 32 GB and a 1.4 in thin-film transistor liquid crystal display (LCD) variant with a resolution of 128 × 128 pixels. It has programmable sampling rates of 250, 500 and 1000 Hz; a bandwidth of 0 Hz to 50% of the selected sampling rate; a CMRR of -105 dB; an input margin of ±2.4 V; a resolution of 286 nV; and a current consumption of 50 mA for an average battery life of 84 h. The ambulatory ECG monitor was evaluated with the commercial data-acquisition system BIOPAC MP36 and its module for ECG LABEL SS2LB, simultaneously comparing the morphologies of two ECG records and obtaining a correlation of 91.78%. For the QRS detection in real time, the implemented algorithm had an error less than 5%. The developed ambulatory ECG monitor can be used for the analysis of the dynamics of the heart rate variability in long-term ECG records and for the development of one's own databases of ECG recordings of normal subjects and patients with cardiovascular and noncardiovascular diseases.

Predictors of New Onset Atrial Fibrillation Burden in the Critically Ill

Introduction: Atrial fibrillation (AF) is common in the intensive care unit (ICU) setting and has been associated with adverse outcomes. In this context, there is increasing research interest in AF burden as a predictor of subsequent adverse events. However, the pathophysiology and drivers of AF burden in the ICU are poorly understood. This study sought to evaluate the predictors of AF burden in critical illness-associated new-onset AF (CI-NOAF). Methods: Out of 7,030 admissions in a tertiary general ICU between December 2015 and September 2018, 309 patients developed CI-NOAF. AF burden was defined as the percentage of monitored time in AF, as extracted from hourly interpretations of continuous ECG monitoring. Low and high AF burden groups were defined relative to the median AF burden. Clinical, laboratory, and echocardiographic parameters were extracted, and multivariable modelling with binary logistic regression was performed to evaluate for independent associations with AF burden. Results: The median AF burden was 7.0%. Factors associated with increased AF burden were age, dyslipidaemia, chronic kidney disease, increased creatinine, CHA₂DS₂-VASc score, ICU admission diagnosis category, amiodarone administration, and left atrial area (LAA). Factors associated with lower AF burden were previous alcohol excess, burden of ventilation, the use of inotropes/vasopressors, and beta blockers. On multivariate analysis, increased LAA, chronic kidney disease, and amiodarone use were independently associated with increased AF burden, whereas beta blocker use was associated with lower AF burden. Conclusion: Left atrial size and chronic cardiovascular comorbidities appear to be the primary drivers of CI-NOAF burden, whereas factors related to acute illness and critical care intervention paradoxically did not appear to be a substantial driver of arrhythmia burden. Further research is needed regarding drivers of AF and the efficacy of rhythm control intervention in this unique setting.

Non-invasive mid-term electrocardiogram patch monitoring is effective in detecting atrial fibrillation

BackgroundAtrial fibrillation (AF) is a cause of serious morbidity such as stroke. Early detection and treatment of AF is important. Current guidelines recommend screening via opportunistic pulse taking or 12‑lead electrocardiogram. Mid-term ECG patch monitors increases the sensitivity of AF detection. MethodsThe Singapore Atrial Fibrillation Study is a prospective multi-centre study aiming to study the incidence of AF in patients with no prior AF and a CHA2DS2-VASc score of at least 1, with the use of a mid-term continuous ECG monitoring device (Spyder ECG). Consecutive patients from both inpatient and outpatient settings were recruited from 3 major hospitals from May 2016 to December 2019. ResultsThree hundred and fifty-five patients were monitored. 6 patients (1.7%) were diagnosed with AF. There were no significant differences in total duration of monitoring between the AF and non-AF group (6.39 ± 3.19 vs 5.42 ± 2.46 days, p = 0.340). Patients with newly detected AF were more likely to have palpitations (50.0% vs 11.8%, p = 0.027). Half of the patients (n = 3, 50.0%) were diagnosed on the first day of monitoring and the rest were diagnosed after 24 h. On univariate analysis, only hyperlipidemia was associated with reduced odds of being diagnosed with AF (OR HR 0.08 CI 0.01–0.74, p = 0.025). In a group of 128 patients who underwent coronary artery bypass grafting and had post-operative ECG monitoring, 9 patients (7.0%) were diagnosed with post-operative AF. ConclusionsThe use of non-invasive mid-term patch-based ECG monitoring is an effective modality for AF screening.

Cardiac arrhythmia and hypoglycaemia in patients receiving haemodialysis with and without diabetes (the CADDY study): protocol for a Danish multicentre cohort study

IntroductionPatients receiving haemodialysis are at increased risk of arrhythmias and sudden cardiac death, but data on arrhythmia burden and the pathophysiology remain limited. Among potential risk factors, hypoglycaemia is proposed...

Epidemiological Features of Non-Sustained Ventricular Tachycardia in Acute Coronary Syndrome with ST Segment Elevation.

Background: Non-Sustained Ventricular Tachycardia is the most frequent ventricular arrhythmias in acute coronary syndrome with ST segment elevation, the assessment of its incidence and prognosis have been the subject of several international studies, but its epidemiological data is lacking in Algeria. Aims: The main objective of our study is the determination of the frequency of Non-Sustained ventricular tachycardia in acute coronary syndrome with ST segment elevation, the secondary objective was the analysis of predictive factors of this arrhythmia, and related mortality. Methods and materials: In this prospective study, conducted in the cardiology department of Hussein Dey hospital (Algiers-Algeria), 467 patients with acute coronary syndrome with elevated ST segment (87 women and 380 men) were enrolled between 28 February 2014 and 16 July 2015. The average age is 60 ± 13 years; at admission, a Holter recorder was attached for continuous ECG monitoring during 48 hours Kruskal’s ANNOVA or H tests were used for comparison of quantitative variables, χ2 test or Fisher’s exact test, were used for qualitative variables, all tests were performed with 1st species risk of 5%. Results: The frequency of Non-Sustained Ventricular Tachycardia is 28.3 % (132 patients), CI 95%: [24.2%-32.4%], multivariate analysis identified the following independent predictors: Age ≤ 58 years, current active smoking, presence of akinetic segment in echocardiography, and short time from symptom onset to emergency room. The risk of in-hospital mortality is low, but not significant (Hazard Ration of 0.156. CI 95%: [0.21-1.177], p = 0.072) Conclusion: NonSustained Ventricular tachycardia is the most frequent arrhythmias during acute coronary syndrome with elevated ST segment, its predictive factors according to our study are: Age ≤ 58 years, current active smoking, presence of akinetic segment in echocardiography, and short time from symptom onset to emergency room. The risk of in-hospital mortality is low, but not significant

Impaired parasympathetic function in long-COVID postural orthostatic tachycardia syndrome – a case-control study

PurposeEighty percent of patients infected by SARS-CoV-2 report persistence of one symptom beyond the 4-week convalescent period. Those with orthostatic tachycardia and orthostatic symptoms mimicking postural tachycardia syndrome, they are defined as Long-COVID POTS [LCP]. This case-control study investigated potential differences in autonomic cardiovascular regulation between LCP patients and healthy controls.MethodsThirteen LCP and 16 healthy controls, all female subjects, were studied without medications. Continuous blood pressure and ECG were recorded during orthostatic stress test, respiratory sinus arrhythmia, and Valsalva maneuver. Time domain and power spectral analysis of heart rate [HR] and systolic blood pressure [SBP] variability were computed characterizing cardiac autonomic control and sympathetic peripheral vasoconstriction.ResultsLCP had higher deltaHR (+ 40 ± 6 vs. + 21 ± 3 bpm, p = 0.004) and deltaSBP (+ 8 ± 4 vs. -1 ± 2 mmHg, p = 0.04) upon standing; 47% had impaired Valsalva maneuver ratio compared with 6.2% in controls (p = 0.01). Spectral analysis revealed that LCP had lower RMSSD (32.1 ± 4.6 vs. 48.9 ± 6.8 ms, p = 0.04) and HFRRI, both in absolute (349 ± 105 vs. 851 ± 253ms2, p = 0.03) and normalized units (32 ± 4 vs. 46 ± 4 n.u., p = 0.02). LFSBP was similar between groups.ConclusionsLCP have reduced cardiovagal modulation, but normal sympathetic cardiac and vasoconstrictive functions. Impaired parasympathetic function may contribute to the pathogenesis of Long-COVID POTS syndrome.

Complete Sino Atrial Block in Acute Coronary Syndrome with ST Segment Elevation: Incidence, Predictive Factors and Related Mortality

Background: Sino atrial block in acute coronary syndrome with ST segment elevation is not rare and may be dangerous by causing severe bradycardia. Its incidence was reported in the literature, but no data about its predictive factors or related mortality, also its epidemiological data is lacking in Algeria. Aims: The main objective of our study is the determination of the frequency of Sino Atrial Block in acute coronary syndrome with ST segment elevation, the secondary objective was the analysis of predictive factors of this Brady arrhythmia, and related mortality. Methods and materials: In this prospective study, conducted in the cardiology department of Hussein Dey hospital (Algiers-Algeria), 467 patients with acute coronary syndrome with elevated ST segment (87 women and 380 men) were enrolled between 28 February 2014 and 16 July 2015. The average age is 60 ± 13 years; at admission, a Holter recorder was attached for continuous ECG monitoring during 48 hours Kruskal’s ANNOVA or H tests were used for comparison of quantitative variables, χ2 test or Fisher’s exact test, were used for qualitative variables, all tests were performed with 1st species risk of 5%. Results: The frequency of complete Sino atrial block is 2.6 % (12 patients), CI 95%: [1.2%-4%], multivariate analysis identified the following independent predictors: right ventricular acute coronary syndrome, infero basal acute coronary syndrome, and large right atrium surface. The risk of mortality expressed by Hazard Ration (HR) is 5.4. (CI95%: [1.2-24], p = 0.024); right acute coronary syndrome is the only predictive factor of mortality identified in our study. Conclusion: Sino atrial block is not rare in acute coronary syndrome with elevated ST segment, its predictive factors according to our study are: right ventricular acute coronary syndrome, infero basal acute coronary syndrome, and large surface of right atrium, its occurrence increases the risk of hospital mortality.

Electrocardiographic Morphology-Voltage-P-Wave-Duration (MVP) Score to Select Patients for Continuous Atrial Fibrillation Screening to Prevent Stroke

Morphology-voltage-P-wave-duration (MVP) score combining P-wave duration (PWD), P-wave voltage in lead I (PWVI), and interatrial block (IAB) has been demonstrated to predict atrial fibrillation (AF). Therefore, this study aimed to examine MVP score and its P-wave components as potential predictors of AF screening effects on stroke prevention. This was a secondary analysis of the LOOP Study (Atrial Fibrillation detected by Continuous ECG Monitoring using Implantable Loop Recorder to prevent Stroke in High-risk Individuals) which randomized older persons (aged 70 to 90years) with additional stroke risk factors to either continuous monitoring with implantable loop recorder and anticoagulation upon detection of AF episodes ≥6minutes (the intervention group), or usual care. A total of 5,759 participants were included in the present analysis, where PWD, PWVI, and IAB were determined through a computerized analysis of 12-lead electrocardiogram and further employed to calculate baseline MVP score (0 to 6) for each participant. In total, 305 (5.3%) had stroke or systemic embolism during follow-up, with a higher risk in the group with MVP score 5 to 6 than those having score 0 to 2 (hazard ratio (HR) 1.54 [95% confidence interval (CI) 1.01 to 2.35]). This risk increase was mainly upheld by participants with IAB (HR 1.62 [95% CI 1.11 to 2.36] for IAB vs no IAB) and with longer PWD (HR 1.37 [95% CI 1.07 to 1.75] for >110 vs ≤110ms). Compared with usual care, implantable loop recorder screening did not significantly reduce the risk of stroke or systemic embolism in any MVP risk categories (HR 0.80 [95% CI 0.60 to 1.08] for MVP score 0 to 2, 0.54 [95% CI 0.16 to 1.85] for MVP score 3 to 4, and 0.89 [95% CI 0.35 to 2.25] for MVP score 5 to 6; pinteraction=0.78). In conclusion, a higher MVP score was associated with an increased stroke risk, but it did not demonstrate an association with effects of AF screening on stroke prevention. These findings should be considered hypothesis-generating and warrant further study.

Sustained Ventricular Tachycardia in Acute Coronary Syndrome with ST Segment Elevation: Incidence, Predictive Factors and Related Mortality.

Background: Sustained Ventricular Tachycardia is the most serious complication; in acute coronary syndrome with ST segment elevation, several international studies have reported incidence and predictive factors of severe ventricular arrhythmias, without identifying sustained ventricular tachycardia separately; also, its epidemiological data is lacking in Algeria. Aims: The main objective of our study is the determination of the frequency of sustained ventricular tachycardia in acute coronary syndrome with ST segment elevation, the secondary objective was the analysis of predictive factors of this arrhythmia, and related mortality. Methods and materials: In this prospective study, conducted in the cardiology department of Hussein Dey hospital (Algiers-Algeria), 467 patients with acute coronary syndrome with elevated ST segment (87 women and 380 men) were enrolled between 28 February 2014 and 16 July 2015. The average age is 60 ± 13 years; at admission, a Holter recorder was attached for continuous ECG monitoring during 48 hours Kruskal’s ANNOVA or H tests were used for comparison of quantitative variables, χ2 test or Fisher’s exact test, were used for qualitative variables, all tests were performed with 1st species risk of 5%. Results: The frequency of Sustained Ventricular Tachycardia is 3.6 % (17 patients), CI 95%: [1.9%-5.3%], multivariate analysis identified the following independent predictors: low diastolic blood pressure, severe coronary artery lesions, Elevated high sensitive troponin concentrations more than 5ng/ml. The risk of mortality expressed by Hazard Ration (HR) is 6. (CI95%: [1.7-21], p = 0.005); the predictors of mortality are: occurrence of ventricular fibrillation and low diastolic blood pressure. Conclusion: Sustained Ventricular tachycardia is the most serious complication during acute coronary syndrome with elevated ST segment, its predictive factors according to our study are: low diastolic blood pressure, severe coronary lesions, Elevated high sensitive troponin concentrations more than 5ng/ml, its occurrence increases the risk of hospital mortality.

Arrhythmias and laboratory abnormalities after an electrical accident: a single-center, retrospective study of 333 cases.

Even though electrical injuries are common in the emergency room, guidelines, consensus, and general recommendations for the management of these patients do not exist in Europe. Documented cases of delayed arrhythmias are rare and their connection with electrical injury has not been fully confirmed. We also use cardio-specific markers for the risk stratification of myocardial injury, but there is no significant study referring to their utility in this clinical situation. These reasons led us to retrospectively analyze all cases of electrical injuries over 23years to determine the prevalence of cardiac arrhythmias (mainly malignant arrhythmias and delayed arrhythmias). We retrospectively searched all patients admitted to the University Hospital in Pilsen, CZ, with a diagnosis of electric injury (ICD diagnostic code T754) from 1997 to 2020. The hospital´s information system was used to research the injury; data were drawn from patient medical records. We identified 333 cases of electrical injury in our hospital. Men accounted for about two-thirds, and women one-third. Children accounted for about one-third of cases. Most were low-voltage injuries (< 1000V, 91.6%). All participants had an initial ECG, and 77.5% of patients had continuous ECG monitoring, usually lasting 24h. Cardiac arrhythmias were noticed in 39 patients (11.7%). The most frequent arrhythmias were: ventricular fibrillation, sinus tachycardia, bradycardia and arrhythmia, atrial fibrillation, and supraventricular tachycardia. The ECG showed cardiac conduction abnormalities in 28 patients (8.1%), and ten patients (3%) had supraventricular or ventricular extrasystoles. In ten cases (3%), we found changes in ST segments and T waves on the initial ECG. Thirty-one patients (9.3%) suffered a loss of consciousness and 50 patients (15.02%) reported paresthesia. The most frequent ion disbalances were hypokalemia (18%) and hypocalcemia (3.3%). Patients with an ion disbalance had significantly more arrhythmias and newly diagnosed cardiac conduction abnormalities. Troponin levels (cTnI or hs-cTnT) were measured in 258 cases (77.48%) and found to be elevated above the 99th percentile in 19 cases (5.7%). Almost one-third of patients had burns of various degrees of seriousness, and 41 patients (12.3%) had concomitant traumatic injuries. Eleven patients underwent pre-hospital resuscitation, three died in the hospital, and another died as result of intracranial hemorrhage. All malignant arrhythmias occurred immediately after the electrical injury, delayed life-threatening arrhythmias were not observed, and no predictive factors of malignant arrhythmias were found. While elevations of cardiac troponins were observed sporadically, they did not appear helpful for risk stratification. In patients with arrhythmias, ion disbalance may be more critical. We concluded that asymptomatic, uninjured adult and pediatric patients with normal initial ECG findings do not need continuous ECG monitoring and may be discharged home. Recommendations for high-risk patients and patients with mild ECG abnormalities at admission are less obvious.

Classification of Continuous ECG Segments - Performance Analysis of a Deep Learning Model.

Classification of electrocardiogram (ECG) signals plays an important role in the diagnosis of heart diseases. It is a complex and non-linear signal, which is the first option to preliminary identify specific pathologies/conditions (e.g., arrhythmias). Currently, the scientific community has proposed a multitude of intelligent systems to automatically process the ECG signal, through deep learning techniques, as well as machine learning, where this present high performance, showing state-of-the-art results. However, most of these models are designed to analyze the ECG signal individually, i.e., segment by segment. The scientific community states that to diagnose a pathology in the ECG signal, it is not enough to analyze a signal segment corresponding to the cardiac cycle, but rather an analysis of successive segments of cardiac cycles, to identify a pathological pattern.In this paper, an intelligent method based on a Convolutional Neural Network 1D paired with a Multilayer Perceptron (CNN 1D+MLP) was evaluated to automatically diagnose a set of pathological conditions, from the analysis of the individual segment of the cardiac cycle. In particular, we intend to study the robustness of the referred method in the analysis of several simultaneous ECG signal segments. Two ECG signal databases were selected, namely: MIT-BIH Arrhythmia Database (D1) and European ST-T Database (D2). The data was processed to create datasets with two, three and five segments in a row, to train and test the performance of the method. The method was evaluated in terms of classification metrics, such as: precision, recall, f1-score, and accuracy, as well as through the calculation of confusion matrices.Overall, the method demonstrated high robustness in the analysis of successive ECG signal segments, which we can conclude that it has the potential to detect anomalous patterns in the ECG signal. In the future, we will use this method to analyze the ECG signal coming in real-time, acquired by a wearable device, through a cloud system.Clinical Relevance-This study evaluates the potential of a deep learning method to classify one or several segments of the cardiac cycle and diagnose pathologies in ECG signals.