ECG Rhythm Research Articles

Stuck Prosthetic Valves: Clinical Implications of Pannus Formation and Gradient Measurement in Surgical Outcomes.

Objective: Stuck prosthetic valves, often resulting from pannus formation or thrombus accumulation, represent a critical complication in prosthetic valve management, carrying significant risks for morbidity and mortality. This study aims to identify factors associated with stuck valve development and assess the effectiveness of interventions in restoring normal valve function. Methods: A total of 27 patients with stuck valves were analyzed, including mitral, aortic, and tricuspid valve cases. Metallic valves were initially implanted in all patients. Interventions included pannus cleaning in suitable cases and valve replacement when necessary, with the replacement being either metallic and biological based on clinical indications. Preoperative and postoperative ECG rhythms, left ventricular ejection fraction (LVEF) values, and gradient measurements were evaluated across patient groups. Results: No significant difference was found in time since initial surgery across valve types (p = 0.67), except in mitral valves, where time was longer in the replacement group (p = 0.02). Maximum gradients were higher in the pannus cleaning group for mitral valves (p = 0.03), while overall gradient values showed no significant differences. Postoperative left ventricular ejection fraction improved significantly in all groups (p < 0.001). Conclusions: The findings highlight the importance of timely intervention in managing stuck prosthetic valves, which are associated with severe hemodynamic compromise and embolic risk. Pannus cleaning emerged as a viable alternative in selected cases where the obstruction was localized, with the valve structure otherwise intact. Biological valve replacements demonstrated superior rhythm stabilization in this study, although definitive conclusions are constrained by the minimal sample size (n = 2). Future research should focus on expanding sample sizes and incorporating comprehensive preoperative analyses to better inform surgical and clinical management strategies.

The association between initial defibrillation dose and outcomes following adult out-of-hospital cardiac arrest resuscitation: A retrospective, multi-agency study.

Effective defibrillation is essential to out-of-hospital cardiac arrest (OHCA) survival. International guidelines recommend initial defibrillation energies between 120 and 360 Joules, which has led to widespread practice variation. Leveraging this natural experiment, we aimed to explore the association between initial defibrillation dose and outcome following OHCA. The ESO Data Collaborative (2018-2022) was used for this nationwide, retrospective study of adult (18-80years of age) non-traumatic OHCA patients who presented with an initially shockable ECG rhythm. We excluded patients if they had ROSC prior to initial defibrillation, a resuscitation-limiting advanced directive, or were residents in a healthcare institution. The primary exposure was initial defibrillation dose, defined as Joules per kilogram of body weight, and the primary outcome was return of spontaneous circulation (ROSC). We included survival to discharge as a secondary outcome. We used multivariable logistic regression modeling to assess the relationship between defibrillation dose and outcome. We analyzed data from 21,121 patients. Of the 12,160 patients linked to a defibrillator manufacturer, 7,240 (59.5%) were treated using a biphasic truncated exponential (BTE) waveform and 4,920 (40.5%) were treated using a rectilinear biphasic (RLB) waveform. Defibrillation dose (per 1J/kg increase) was not associated with ROSC (BTE aOR: 0.97 [0.92, 1.01], n=7,240; RLB aOR: 1.00 [0.92, 1.09], n=4,920; all aOR: 1.01 [0.98, 1.04], 21,121) or survival (BTE aOR: 0.98 [0.87, 1.10], n=1,245; RLB aOR: 0.89 [0.70, 1.12], n=775; all aOR: 1.00 [0.92, 1.08], n=2,981). Initial defibrillation dose was not associated with outcome in this nationwide cohort.

Altered circadian rhythmicity of the QT interval predicts mortality in a large real-world academic hospital population.

Small studies have shown that the QT interval follows a circadian rhythm. This finding has never been confirmed in a large real-world hospital population and the clinical meaning of disrupted rhythmicity remains unknown. In this cohort study, all consecutive adult patients with at least one 12-lead ECG acquired between 1991 and 2021 were considered. Sinus rhythm ECGs without QRS conduction or ST-segment abnormalities obtained at the wards or outpatient clinic were included. The QT interval was corrected for age, sex and ventricular rate in a personalized manner. Subsequently, the added value of a 24-h sinusoid of time-of-day was evaluated. An individual 24-h QT interval amplitude was obtained from the model in a subset with patients that had at least 3 ECGs of which one during the night before their last ECG. The association of this individual QT interval with all-cause mortality was assessed using a left-truncated Cox regression model. The baseline QT correction model was fitted using 237,555 ECGs of 100,644 patients. The personalized corrected QT interval had no relationship with ventricular rate (r=-0.008). Adding the 24-h sinusoidal to the baseline model resulted in a significantly better fit (p<0.0001). The mean circadian variation of the QT interval was 15ms, with the maximum QT duration around midnight and an effect that is largest in young female patients. A non-linear relationship between peak-to-trough amplitude in QT interval rhythmicity and all-cause mortality was found, with both lower and higher values associated with increased risk. Using heterogeneous, real-world hospital data of more than 100,000 patients, circadian rhythmicity proved to be an independent determinant of the QT interval. Both increased and diminished QT rhythmicity was shown to be a predictor of all-cause mortality. QT interval should be corrected for the time-of-day and altered circadian rhythmicity should trigger awareness of increased mortality risk (https://qt.ecgx.ai).

Abstract Su402: Comprehensive Assessment of Chest Compression Quality Across All Phases of Prehospital Care Using a Manikin

Background: High-quality cardiopulmonary resuscitation (CPR) is crucial for improving the prognosis of out-of-hospital cardiac arrest (OHCA) patients. The quality of chest compressions may vary during different phases of prehospital care. Objectives: To investigate changes in chest compression quality during prehospital activities and identify the causes. Methods: Eleven emergency medical teams of three members each participated. Using a manikin (Laerdal QCPR), we measured achievement rates of compression depth (≥5 cm) and recoil, compression rate, and chest compression fraction (CCF). The process from the scene to the hospital bed was divided into four phases: 1) on-site, 2) transport from the scene to the ambulance (canvas stretcher), 3) in the ambulance, 4) transport from the ambulance to the hospital bed (wheeled stretcher). We analyzed the quality changes in chest compressions and the causes of degradation or interruptions. Each team performed both manual CPR (Man-CPR) and mechanical CPR (Mech-CPR) using the LUCAS3 device. The scenario assumed cardiac arrest on the second floor, transport down stairs to the ambulance, and a 15-minute drive to the hospital. ACLS was established in Phase 1 and continued until hospital arrival. In Mech-CPR, a mechanical CPR device was applied in Phase 1 and used throughout all phases. Results: Man-CPR showed lower compression depth achievement in Phases 2 and 4 compared to Phases 1 and 3, mainly due to transport transitions (Fig. 1). CCF was high in Phases 1 and 3 but decreased in Phases 2 and 4 due to these transitions. Interruptions in Phases 1 and 3 were due to checking ECG rhythm, securing an airway, and confirming ventilation. Recoil achievement was low across all phases. Mech-CPR showed high achievement rates for compression depth and recoil across all phases and maintained high CCF. However, Man-CPR had a higher CCF in Phase 1 than Mech-CPR due to interruptions for device application. Mech-CPR had no degradation due to dual work, but improper application caused long degradations and interruptions. The longest interruption times were 69 seconds (transport) for Man-CPR and 25 seconds (device application) for Mech-CPR. Both Man-CPR and Mech-CPR maintained compression rates within the guideline range of 100-120/min, with Man-CPR tending to be faster. Conclusion: Chest compression quality varies from the scene to hospital arrival. Man-CPR and Mech-CPR have different causes of quality changes and interruptions.

Accuracy of the Apple Watch in detecting atrial fibrillation among patients undergoing 24-hour Holter monitoring

Abstract Background As direct-to-consumer wearable devices like the Apple Watch become more common, an increasing number of patients arrive at clinics with reports of irregular rhythms captured on their devices. Purpose This study sought to assess the accuracy of a commonly used smart wearable device (Apple Watch) in detecting atrial fibrillation. Methods We enrolled 140 patients referred for 24-hour Holter monitoring in a Cardiovascular Center. Following thorough disclosure, participants were instructed to wear an Apple Watch provided by the researchers in addition to the Holter monitor to facilitate comparison. The Apple Watch was selected due to its widespread usage among patients. Participants were instructed to record an ECG using the Apple Watch hourly, or more frequently while awake. The objective of the study was to evaluate the sensitivity and specificity of the irregular rhythm notification and ECG-based detection features of the Apple Watch in comparison to the conventional 24-hour Holter monitoring for atrial fibrillation detection. Results The irregular rhythm notification feature of the Apple Watch exhibited a low sensitivity of 21.4% but achieved a high specificity of 100% in detecting atrial fibrillation. Meanwhile, the ECG-based detection feature of the Apple Watch analyzed from 1,295 ECGs captured by the participants when compared in real-time to their ECG rhythms recorded by the Holter monitor, revealed a high level of agreement with a sensitivity of 100% and a specificity of 99.1%. Conclusion The low sensitivity of the irregular notification feature of the Apple watch in detecting atrial fibrillation cautions against relying solely on it to rule out atrial fibrillation as the cause of a patient’s symptoms. Nevertheless, the high concordance of manually taken Apple watch ECGs positions the device as a reliable tool for detecting atrial fibrillation through its ECG-based detection feature.

MULTI-LEVEL CLASSIFICATION BASED ON DEEP LEARNING FOR ACCURATE RISK STRATIFICATION OF ARRHYTHMIAS

Arrhythmias, also known as irregular heartbeats, are important health problems that must be accurately identified to diagnose and treat cardiovascular disease. Within the scope of this study, a network for classifying arrhythmias, which are important in the diagnosis and treatment of cardiovascular diseases, was proposed by using one-dimensional convolutional neural network (1D CNN), one of the deep learning techniques. With the proposed 1D-CNN architecture, arrhythmia types and normal rhythm ECGs were subjected to a more detailed examination from general to specific according to urgency situations. In the classifications made, first of all, a binary classification was made and an evaluation was made as whether there was a life risk or not. In triple, quadruple and six-fold classification, the detection of arrhythmia status is detailed. More complex classifications have helped to define different types of arrhythmias in more detail. This study proposes a deep learning network for automatic identification and classification of arrhythmias and shows that different arrhythmia conditions can be diagnosed with a single network model by applying the proposed network structure to multi-class arrhythmia disorders.

ECG and Echocardiography Findings in Hypertension: A Comparative Study Male versus Female at the Gabriel Touré University Hospital (UH-GT)

Background: There is a lack of data on ECG and echocardiographic modifications in hypertensive patients in our setting that justify their inclusion. Methods: This study aims to compare induced ECG and echocardiographic modifications in female and male hypertensive patients. It was a cross-sectional study among outpatients seen in the cardiology department of the UH-GT in Bamako-Mali and included hypertensive patients aged 18 years or older. Data were first collected on a survey form, inserted into a MS Access database, and finally analyzed with IBM SPSS software. Quantitative data are presented as mean with standard deviation and qualitative data as proportion. The level of significance for the statistical test was set at 5%. Results: Of 524 patients, 52.9% were new patients, and 96% had no known cardiac disease. The female sex represented 61.8%. The mean age was 55.33±15.013 years, and obesity based on body mass index was more prevalent in women's sex (81 vs. 19% in men's sex). The global prevalence of HTN was 38.8% in males and 61.1% in females. Among ECG modifications, rhythm disorders and hypertrophy were significantly higher in males, respectively (37.5 vs. 21.9 and 49.5 vs. 29). The most frequent echocardiographic signs included left ventricular end diastolic diameter (LVEDD) and interventricular septum (IVS), with 53 mm vs. 49,3 mm and 10 vs. 9,3 mm (&lt;0.001). Other structural echocardiographic changes were an increase in left ventricular mass and index left ventricular mass with, respectively, 210.5 vs. 176.4 g and 115.4 vs. 96.8 g/m2. Conclusion: The prevalence of hypertension is high in both sexes, with consequences led by left ventricular hypertrophy in ECG and echocardiography. The higher prevalence of female HTN must be further studied, as must the associated factors.

Is admission neutrophil-to-lymphocyte ratio an outcome predictor in critically ill multiple trauma patients? A retrospective single-centre cross-sectional study

Background Trauma is a global health concern with a high mortality rate. Research suggests a potential link between neutrophil-to-lymphocyte ratio (NLR) and mortality. This study aims to assess the prognostic value of NLR in intensive care unit (ICU)-admitted individuals with multiple trauma. Methods This study reviewed medical records of multiple trauma patients admitted to the ICU of Shahid Mohammadi Hospital in Bandar Abbas, Iran, from 2020 to 2021. Variables assessed included age, sex, blood pressure, Glasgow Coma Scale, Injury Severity Score, NLR, trauma details, surgical procedures, hospital and ICU length of stay, duration of mechanical ventilation, and mortality. Results In the study, 160 multiple trauma patients were analyzed, with an average age of 34.13 ± 14.74 years. Among them, 130 (81.3%) were male and 75 (46.9%) died. The mean NLR did not show a significant difference between survivors and non-survivors ( p = 0.853). The predictive ability of NLR for mortality, as measured by the area under the receiver operating characteristic curve, was 0.530 (95% confidence interval [CI] 0.440; 0.620, p = 0.517). Patients who died had higher rates of ICU admission, mechanical ventilation requirement, longer mechanical ventilation duration, and longer hospital and ICU stays (all p &lt; 0.001). Multivariable logistic regression analysis found that a non-sinus rhythm in the admission ECG was associated with approximately eight times higher odds of mortality compared to a sinus rhythm (adjusted odds ratio = 7.961, 95% CI 1.724; 36.759, p = 0.008). No significant association was found between NLR and mortality in univariable binary logistic regression, even after adjusting for various factors (adjusted OR = 0.967, 95% CI 0.989; 1.042, p = 0.375). Conclusions Our findings indicate that admission NLR did not demonstrate efficacy as a prognostic indicator of mortality among patients with multiple trauma admitted to the ICU.

Predicting atrial fibrillation ablation success: a novel approach using pre-procedure sinus rhythm ecg and deep learning

Abstract Introduction Pulmonary vein isolation (PVI) has been the corner stone of the treatment of patients with atrial fibrillation (AF), yet its efficacy varies notably between patient groups. Specifically, it shows reduced efficacy in individuals with persistent AF and those with atrial fibrosis. Recent advancements suggest that additional substrate modification could enhance outcomes in specific patient groups. Therefore, predicting the outcomes of lone PVI could help in stratifying patients who would benefit most from this additional substrate modification. Addressing this gap, our study explores the prognostication of PVI outcomes using pre-procedural 12-lead ECG recordings taken in Sinus rhythm, employing advanced deep learning techniques. Methods This retrospective study analyzed 209 patients with paroxysmal and persistent AF who underwent PVI. These patients were followed up for 12 months after the blanking period. Pre-procedural sinus rhythm 12-lead ECGs were processed using an innovative deep learning architecture, integrating Long Short-Term Memory and Convolutional Neural Networks with a cross-attention module. This multimodal deep learning model was trained using ECG and clinical covariates like age, sex, and BMI to predict binary outcomes – AF type (Paroxysmal or Persistent) and AF recurrence. The model's efficacy was evaluated through a 5-fold stratified cross-validation to ensure accuracy and reliability. Model was also tested using only ECG data. Results The multimodal deep learning model performed significantly better as compared to the model trained using ECG data only. The multimodal deep learning model achieved an accuracy of 75.56% and a sensitivity of 82% in prognosticating ablation outcomes. Additionally, the model demonstrated a significant capability in classifying AF into paroxysmal or persistent types with an accuracy of 86.67% and a recall of 89%. Conclusion Our deep learning approach in analyzing sinus rhythm ECG recordings shows promising results in predicting PVI outcomes and identifying AF types. This approach could offer a more accessible and cost-effective tool to stratify AF patients undergoing PVI, identifying those less likely to benefit from standard procedures. Such insights can assist physicians and patients in determining ablation candidacy and selecting the most appropriate ablation strategy and technique.Proposed StrategyDeep learning model approach

Heart rate dynamics after pulmonary vein isolation: pulsed-field vs. radiofrequency ablation

Abstract Background The autonomic nervous system (ANS) plays a pivotal role in the onset and maintenance of atrial fibrillation (AF). During thermal ablation, the epicardial ganglionated plexi (GP) can inadvertently be affected, as indicated by a post-ablation increase in heart rate (HR), potentially impacting post-procedural outcomes. Pulsed-field ablation (PFA) offers a safer and potentially more effective alternative, as lesion transmurality is not inversely related to safety as in thermal ablation. However, PFA's tissue selectivity may limit its effectiveness in ablating potential AF triggers like GP. Purpose We aimed to assess the impact of PF and RF energy on GP ablation by examining HR changes following PVI procedures. Methods We examined consecutive paroxysmal AF patients undergoing PVI at a single center, using either a variable-loop circular PFA catheter, as part of the inspIRE trial, or a conventional point-by-point RF catheter (1:2 ratio). ECGs were collected before and after ablation at multiple time points, including 1-hour, 1-day, 1-month, and 3-month intervals, with a 24-hour Holter ECG at 3 months. Patients without obtainable sinus rhythm ECGs at these time points were excluded. We also gathered data on post-ablation antiarrhythmic drug and beta-blocker usage. Data are reported as mean±SD, and analysis employed Student’s t-tests, paired t-tests, chi-squared tests, and multiple linear regression analysis to identify influencing factors. Results A total of 105 patients were included (PF = 35, RF = 70). Baseline demographics were similar (Table A). In the RF group, HR significantly increased at all measured time-points. In contrast, this trend was not observed in the PF group (Figure A and B). Following the procedure, the RF cohort exhibited a significantly higher HR compared to PF (7.3±10.3 vs. 0.8±11 at 1-day, p=0.018), and this difference persisted after 3 months (8.5±10.1 vs. 0.9±9, p&amp;lt;0.001, Figure C). These findings remained consistent when HR was assessed using Holter ECG data (HR at 3 months: mean 72.1±8.8 vs 65.8±9.4, min 55.2 vs 48.9; p=0.002, p=0.001, Figure D). The use of RF energy was the only predictor of HR increase after the ablation procedure (β = 7.687, p &amp;lt; 0.001, Table B). Conclusion Our findings indicates that PFA does not increase resting HR as seen with thermal RF ablation, suggesting limited effect on ANS modulation. The role of adjunctive GP ablation during PVI procedures remains a topic of debate.While PFA shows promising improvement in lesion durability, current evidence does not conclusively establish its advantage over RF. This invites contemplation about whether the addition of GP ablation in RF procedures could be a contributing factor. The absence of HR acceleration may pose issues for patients with sick sinus syndrome or pure vagally mediated AF. Further research is essential to confirm these findings and their clinical implications.Central illustrationTables

Prognostic Impact of Sinus Rhythm in Atrial Fibrillation Patients: Separating Rhythm Outcomes From Randomized Strategy Findings From the CABANA Trial.

Clinically detected atrial fibrillation (AF) is associated with a significant increase in mortality and other adverse cardiovascular events. Since the advent of effective methods for AF rhythm control, investigators have attempted to determine how much these adverse prognostic AF effects could be mitigated by the restoration of sinus rhythm (SR) and whether the method used mattered. The CABANA trial (Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation) randomized 2204 AF patients to ablation versus drug therapy, of which 1240 patients were monitored in follow-up using the CABANA ECG rhythm monitoring system. To assess the prognostic benefits of SR, we performed a prespecified analysis using Cox survival modeling with heart rhythm as a time-dependent variable and randomized treatment group as a stratification factor. In the 1240 patient study cohort, 883 (71.2%) had documented AF at some point during their postblanking follow-up. Among the 883 patients, 671 (76.0%) experienced AF within the first year of postblanking follow-up, and 212 (24.0%) experienced their first AF after ≥1 year of postblanking follow-up. The primary CABANA end point (death, disabling stroke, serious bleeding, or cardiac arrest) occurred in 95 (10.8%) of the 883 patients with documented AF and in 29 (8.1%) of the 357 patients with no AF recorded during follow-up. In multivariable time-dependent analysis, the presence of SR (compared with non-SR) was associated with a significantly reduced risk of the primary end point (adjusted hazard ratio, 0.57 [95% CI, 0.38-0.85]; P=0.006; independent of treatment strategy [ablation versus drugs]). Corresponding results for all-cause mortality were adjusted hazard ratio of 0.59 [95% CI, 0.35-1.01]; P=0.053). In patients in the CABANA trial with detailed long-term rhythm follow-up, increased time in SR was associated with a clinically consequential decrease in mortality and other adverse prognostic events. The predictive value of SR was independent of the therapeutic approach responsible for reducing the burden of detectable AF. URL: https://clinicaltrials.gov; Unique Identifier: NCT00911508.

Electrocardiogram Electrode Positioning on the Back During Echocardiography: An Exploratory Cross-Sectional Study.

ECG interpretation is sometimes difficult due to baseline fluctuations and electrode detachments when placed on the subjects' front side, leading to misinterpretation of the rhythms and phases of the cardiac cycle. We aimed to compare the differences in the wave amplitudes and respiratory variations between conventional ECG electrode positioning on the front side of patients and an alternative position on the backs of patients. Echocardiography was performed in 85 patients lying in the left lateral position. We attached the red electrode to the right clavicle, the yellow to the left clavicle, and the green to the left lateral abdomen on the front side of the patients; on the back, we attached the electrode to the right clavicle, the right upper posterior iliac spine, and the left upper posterior iliac spine. The ECG monitor amplitudes were greater on the front side compared to the back side, but the BF-breath values were smaller on the back side (6.0 pixels) compared to the front side (10.5 pixels, p<0.05). The P wave amplitude divided by the BF-breath on the back side was greater than that seen on the front side (2.8 vs. 1.8, p<0.05), whereas the QRS amplitude divided by the BF-breath was 15.0 and 16.3, respectively (p=ns). As an alternative to front-side ECG monitoring, electrodes placed on the back can help avoid misinterpretation of the ECG rhythms and the phases of the cardiac cycle due to respiration during echocardiography.

Lead-Specific Performance for Atrial Fibrillation Detection in Convolutional Neural Network Models Using Sinus Rhythm Electrocardiography

Background: We developed a convolutional neural network (CNN) model to detect atrial fibrillation (AF) using the sinus rhythm ECG (SR-ECG). However, the diagnostic performance of the CNN model based on different ECG leads remains unclear. Methods and Results: In this retrospective analysis of a single-center, prospective cohort study, we identified 616 AF cases and 3,412 SR cases for the modeling dataset among new patients (n=19,170). The modeling dataset included SR-ECGs obtained within 31 days from AF-ECGs in AF cases and SR cases with follow-up ≥1,095 days. We evaluated the CNN model's performance for AF detection using 8-lead (I, II, and V1-6), single-lead, and double-lead ECGs through 5-fold cross-validation. The CNN model achieved an area under the curve (AUC) of 0.872 (95% confidence interval (CI): 0.856-0.888) and an odds ratio of 15.24 (95% CI: 12.42-18.72) for AF detection using the eight-lead ECG. Among the single-lead and double-lead ECGs, the double-lead ECG using leads I and V1 yielded an AUC of 0.871 (95% CI: 0.856-0.886) with an odds ratio of 14.34 (95% CI: 11.64-17.67). Conclusions: We assessed the performance of a CNN model for detecting AF using eight-lead, single-lead, and double-lead SR-ECGs. The model's performance with a double-lead (I, V1) ECG was comparable to that of the 8-lead ECG, suggesting its potential as an alternative for AF screening using SR-ECG.

Directional statistics-inspired end-to-end atrial fibrillation detection model based on ECG rhythm

Numerous algorithms designed for detecting atrial fibrillation (AF) often exhibit limitations in extracting essential rhythm features, leading to challenges in accurately discerning ectopic beats and consequently yielding suboptimal detection performance. In this study, we explored the distribution patterns of R-R intervals (RRIs) in both AF and specific rhythms, such as atrial premature beats (APBs) and normal sinus rhythm (NSR). For the first time, we employed the Sobolev test statistics, a method used in directional statistics to assess spherical uniformity, to quantify the irregularity and variability characteristics of RRIs. We developed an end-to-end learnable model for detecting AF by leveraging this approach. A cross-dataset validation method is employed to train and test the proposed model. This involved the use of a simulated dataset and eight distinct real-world databases. Notably, when trained on the Computing in Cardiology Challenge 2017 (C2017) and tested on the MIT-BIH Atrial Fibrillation Database (AFDB), our model, designed to take only a sequence of 32 RRIs as input, achieved a sensitivity of 96.2%, specificity of 98.2%, and accuracy of 97.3%. The results illustrate its competitive standing against the existing methods for AF detection and its enhanced resilience to ectopic beats. Unlike existing deep learning-based AF detection models, our model prioritizes interpretability, boasts lower computational complexity (with fewer than 2000 learnable parameters), and demonstrates superior generalization capabilities. This will help improve the quality of long-term real-time monitoring and management of AF, reduce the burden on clinicians, and ultimately improve patient outcomes.

Artificial intelligence-enhanced electrocardiogram for arrhythmogenic right ventricular cardiomyopathy detection.

ECG abnormalities are often the first signs of arrhythmogenic right ventricular cardiomyopathy (ARVC) and we hypothesized that an artificial intelligence (AI)-enhanced ECG could help identify patients with ARVC and serve as a valuable disease-detection tool. We created a convolutional neural network to detect ARVC using a 12-lead ECG. All patients with ARVC who met the 2010 task force criteria and had disease-causative genetic variants were included. All case ECGs were randomly assigned in an 8:1:1 ratio into training, validation, and testing groups. The case ECGs were age- and sex-matched with control ECGs at our institution in a 1:100 ratio. Seventy-seven patients (51% male; mean age 47.2 ± 19.9), including 56 patients with PKP2, 7 with DSG2, 6 with DSC2, 6 with DSP, and 2 with JUP were included. The model was trained using 61 case ECGs and 5009 control ECGs; validated with 7 case ECGs and 678 control ECGs and tested in 22 case ECGs and 1256 control ECGs. The sensitivity, specificity, positive and negative predictive values of the model were 77.3, 62.9, 3.32, and 99.4%, respectively. The area under the curve for rhythm ECG and median beat ECG was 0.75 and 0.76, respectively. Our study found that the model performed well in excluding ARVC and supports the concept that the AI ECG can serve as a biomarker for ARVC if a larger cohort were available for network training. A multicentre study including patients with ARVC from other centres would be the next step in refining, testing, and validating this algorithm.

Effect of direct exposure to ringing mobile phone waves on ECG heart rate and rhythm among healthy adults

The effect of electromagnetic wave from mobile phones on human health is of great interest, the current study was designed to investigate the effect of mobile phone electromagnetic waves on ECG heart rate and rhythm among different healthy adult volunteers’ ages and sex while mobile phone was placed on the chest pocket level during ringing mode. It was an experimental, comparative study conducted in the period from march 2014 to August 2016 in north of Sudan at Elsheikh Abdallah Elbadri University among 850 volunteers, Sudanese and other nationalities.500 male and 350 females, aged 16 - 49 years were included in the study. ECG was done before and after exposure to ringing mobile phone. Significant changes in ECG heart rate and rhythm was detected and the results was found to be consistent in males and females’ group. The study conclude that mobile phone is not a safety device and should not be used by medical staff inside the ECG rooms.

Autopsy findings and cardiac arrest rhythms in young obese patients with sudden cardiac death of uncertain etiology

Abstract Background Obesity is associated with an increased risk of sudden cardiac death (SCD) which can be particularly devastating in young adults. In a significant proportion of SCD cases in the young, a specific cause cannot be identified. Purpose The aim of this retrospective analysis was to describe the demographics, pathological changes and cardiac arrest rhythm in young obese individuals with SCD of otherwise unknown etiology. Methods Between July 2000 and December 2018, the National Coronial Information System (NCIS) identified cases of young obese (body mass index ≥ 30) individuals with SCD between 17-35 years of age (SCD-obesity). Autopsy reports of individuals with SCD where known causes had been excluded were compared to 2 matched control cohorts of death due to motor vehicle accidents (MVA) (first group matched for age, sex, height and weight (MVA-BMI-matched) and second group matched for age and sex (MVA-age-matched)). Additionally, electrocardiographic rhythms at cardiac arrest were obtained through state-wide ambulance services for SCD-obesity individuals. Results We identified 409 cases of SCD in young obese individuals, of which 94 cases met the inclusion criteria (figure 1). Mean age was 28.44±5.6 years (range 17-35). SCD-obesity individuals were commonly males (71%). SCD-obesity individuals had significantly higher cardiac masses (521g vs 417g, p&amp;lt;0.001) compared to the MVA-BMI-matched cohort. SCD-obesity individuals also had significantly increased left ventricular wall thickness (15.6mm vs 13.5mm, p&amp;lt;0.001) and increased rates of left ventricular fibrosis (73% vs 52%, p=0.045) compared to the MVA-BMI-matched cohort. ECG rhythm strips were available for 71 (72%) SCD-obesity cases, of which 16 (23%) were unwitnessed. Asystole was noted on 7 (46.67%) of witnessed cases, and 6 (40%) had a ventricular tachycardia or fibrillation (figure 2). Conclusions SCD-obesity individuals had increased cardiac organ masses, left ventricular wall thickness and cardiac fibrosis. The cardiac arrest rhythm recorded in witnessed cases were predominantly asystole and ventricular arrythmia. Future studies are needed to determine the pathological mechanisms explaining these abnormalities in young obese sufferers of SCD.Figure 1:Case identificationFigure 2:Results

Left-ventricular unloading with Impella during refractory cardiac arrest treated with veno-arterial extracorporeal membrane oxygenation - A systematic review and meta-analysis

Abstract Background Extracorporeal cardio-pulmonary resuscitation (ECPR) is the implementation of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) during refractory cardiac arrest. The role of left-ventricular (LV) unloading with Impella in addition to VA-ECMO ("ECMELLA") during ECPR is unlear. Purpose This is the first systematic review and meta-analysis to characterise patients receiving LV unloading and to compare in-hospital mortality between ECMELLA and VA-ECMO treatment during ECPR. Methods A systematic review and meta-analysis was performed according to the PRISMA checklist on clinical studies with adult patients with refractory cardiac arrest treated with ECMELLA or VA-ECMO as part of ECPR. The meta-analysis was performed by using a random-effects model. Risk of bias was assessed with Cochrane ROBINS-I tool, heterogeneity with Cochrane Q test and publication bias with funnel plots. Results Altogether, 13 study records from 32 tertiary care centers with a total of 1,037 adult patients with ECPR were included, out of which 785 patients (75.7%) received VA-ECMO and 252 (24.3%) ECMELLA support. Compared to VA-ECMO, the ECMELLA group was comprised of more male patients (71.4% vs. 57.3%), more patients with initial shockable ECG rhythms (55.2% vs. 40.3%), lower pre-ECPR pH (7.07 vs. 7.11) and higher lactate levels (10.9 vs. 10.1 mmol/L), as well as higher rates of acute myocardial infarction (75.0% vs. 41.9%) and percutaneous coronary interventions (71.8% vs. 35.4%) (Table). Age, rate of out-of-hospital cardiac arrest and low-flow times were similar between both treatment groups. Compared to ECMELLA, VA-ECMO alone was more frequently used in pulmonary embolism (6.4% vs. 0.4%) and miscellaneous causes of cardiac arrest (19.0% vs. 4.4%). ECMELLA support was associated with a 47% reduced mortality risk [95% Confidence Interval 0.31-0.93] compared to VA-ECMO alone: 123 (48.8%) vs. 539 (68.7%) patients (P=0.026). Patients with ECMELLA had a longer hospital length of stay (18.7 days vs. 10.6 days). Results remained robust in sensitivity analyses after exclusion of smaller studies and gray literature. Conclusions ECMELLA support was predominantly utilised in patients with acute myocardial infarction and VA-ECMO for pulmonary embolism and miscellaneous causes of cardiac arrest across institutions. Indications and frequency of ECMELLA use varied strongly between institutions. ECMELLA support during ECPR was associated with improved survival across studies and might be considered in well selected patients with refractory cardiac arrest. Further scientific evidence is urgently required to elaborate standardised guidelines for the use of LV unloading during ECPR.

Abstract 362: Multicenter, Retrospective Study of Ventricular Fibrillation Visualized by Echocardiogram With a Non-Shockable Elelctrocardiogram Following Out-of-Hospital Cardiac Arrest

Introduction: Cardiac rhythm by ECG can be different from cardiac rhythm visualized by echocardiography (echo). Cardiac arrest interventions are largely based on the ECG rhythm and some patients with ventricular fibrillation (vfib) demonstrating a non-shockable ECG may not be rapidly defibrillated. Hypothesis: A significant percentage of out of hospital cardiac arrest (OHCA) with vfib are unrecognized by ECG. Goals - To measure the prevalence and survival outcomes for patients with a non-shockable ECG but vfib by echo. Methods: Analysis of echo images recorded during a previous multi-center, observational study of OHCA patients. ECG and echo during initial pause in CPR at arrival to the Emergency Department (ED) were reviewed. Echo imaging was reviewed for the presence of visible vfib blinded to all patient information. Image interpretation was performed by two experienced physicians with adjudication by a third. ECG interpretation was unblinded to patient information. Primary outcome was survival to hospital admission. Data is presented as mean (95%CI) Results - Vfib was unrecognized by ECG in 31% of patients in vfib at ED arrival (22 of 71). See Figure. Survival to hospital admission for patients with ECG vfib (18.2%, 95%CI 10.2-30.3) and echo vfib (18.2%, 95%CI 6.7-39.1) was similar. All 55 patients who presented in ECG vfib were defibrillated immediately, and 11 of 22 patients with a non-shockable ECG but echo vfib were defibrillated, but during a subsequent pause in CPR. Patients with ECG vfib had no echo before defibrillation. Patients with echo vfib demonstrated ECG PEA (n=9, 41%), asystole (n=7, 32%), or ECG vfib defibrillated to a non-shockable ECG with continued echo vfib that was not subsequently defibrillated (n=6, 11%). Conclusion: A significant percentage of OHCA vfib was not recognized at arrival to the ED, with 31% demonstrating a non-shockable ECG rhythm but vfib on echo. OHCA survival rate for echo vfib is similar to ECG vfib.

Abstract 15606: Effectiveness and Safety of the Dual Epicardial &amp; Endocardial Procedure (DEEP) Approach for Treatment of Subjects With Persistent or Long Standing Persistent Atrial Fibrillation (PersAF/LSPAF) With Radiofrequency Ablation

Background: A collaborative approach between Electrophysiologists (EP) and Cardiothoracic Surgeons (CTS) to effectively target pulmonary veins (PVs) and substrate beyond PVs may improve outcomes for persistent and longstanding persistent AF (PersAF/LSPerAF). Hypothesis: A minimally invasive hybrid approach of bilateral thoracoscopic epicardial ablation and left atrial appendage exclusion (LAAE) with endocardial mapping/ablation (Hybrid approach) is safe and effective to treat advanced AF patients who have failed medical therapy. Aim: DEEP (NCT02393885) aims to establish safety and effectiveness of a Bipolar Radiofrequency (RF) System in a Hybrid approach to treat PersAF/LSPerAF. Methods: DEEP is a prospective, international, single arm trial at 17 sites. Key eligibility: adults with drug refractory PersAF/LSPerAF, left atrial diameter (LAD) ≤5.5cm, failed class I/III AAD, and ≤2 previous failed endocardial catheter ablations (CA). Epicardial surgical ablation included PV isolation, roof and floor lines (posterior LA box), left superior PV to LAA lesion, ganglionic plexi and Ligament of Marshall ablation and LAAE. CA followed 91-121 D post epicardial procedure. After 90 D blanking and 90 D AAD optimization periods, 24-hr rhythm monitoring and ECG were performed 6 and 12 M post CA with symptom driven monitoring between. Primary effectiveness was defined as freedom from atrial arrhythmia (&gt;30 sec) absent new/increased dose of previously failed AAD through 12 M. Safety was device/procedure-related SAEs within 30 D of epicardial ablation and 7 D of CA in all who received anesthesia. Results: Ninety patients were enrolled in 2015-2020, 83.3% PersAF, 16.7% LSPerAF, mean age 63.4±7.74 yrs, 83.3% male, mean BMI 29.9, CHAD2DS2-VASc median 2.0 (1.0, 3.0), 48% failed CA, median AF duration 3.8 yrs, mean LAD 4.5cm. Primary effectiveness 70.6% (60/85; 95% CI 60.9%, 80.3%, p=0.0232) and freedom from AF through 12 M 78.8% (p=0.0002). The adverse event rate was 6.7% (6/90); equal in epi- and endocardial cohort. Both primary endpoints met prespecified success criteria. Conclusion: A collaborative approach between EP and CTS to Hybrid ablation is effective for PersAF/LSerPAF when benefit-risk is deemed favorable, given limited alternative treatments.