ECG Screening Research Articles

Fallacy of Median Door-to-ECG Time: Hidden Opportunities for STEMI Screening Improvement.

BackgroundST‐segment elevation myocardial infarction (STEMI) guidelines recommend screening arriving emergency department (ED) patients for an early ECG in those with symptoms concerning for myocardial ischemia. Process measures target median door‐to‐ECG (D2E) time of 10 minutes.Methods and ResultsThis 3‐year descriptive retrospective cohort study, including 676 ED‐diagnosed patients with STEMI from 10 geographically diverse facilities across the United States, examines an alternative approach to quantifying performance: proportion of patients meeting the goal of D2E≤10 minutes. We also identified characteristics associated with D2E>10 minutes and estimated the proportion of patients with screening ECG occurring during intake, triage, and main ED care periods. We found overall median D2E was 7 minutes (IQR:4–16; range: 0–1407 minutes; range of ED medians: 5–11 minutes). Proportion of patients with D2E>10 minutes was 37.9% (ED range: 21.5%–57.1%). Patients with D2E>10 minutes, compared to those with D2E≤10 minutes, were more likely female (32.8% versus 22.6%, P=0.005), Black (23.4% versus 12.4%, P=0.005), non‐English speaking (24.6% versus 19.5%, P=0.032), diabetic (40.2% versus 30.2%, P=0.010), and less frequently reported chest pain (63.3% versus 87.4%, P<0.001). ECGs were performed during ED intake in 62.1% of visits, ED triage in 25.3%, and main ED care in 12.6%.ConclusionsExamining D2E>10 minutes can identify opportunities to improve care for more ED patients with STEMI. Our findings suggest sex, race, language, and diabetes are associated with STEMI diagnostic delays. Moving the acquisition of ECGs completed during triage to intake could achieve the D2E≤10 minutes goal for 87.4% of ED patients with STEMI. Sophisticated screening, accounting for differential risk and diversity in STEMI presentations, may further improve timely detection.

PO-629-04 PHENOTYPES OF OVERDIAGNOSED LONG QT SYNDROME

Long QT syndrome (LQTS) is a potentially lethal, yet highly treatable, genetic heart disease that predisposes individuals to arrhythmic syncope/seizure, sudden cardiac arrest, or sudden cardiac death (SCD). Although well intended, increased physician and public awareness of LQTS-associated warning signs and an increase in ECG screening programs may contribute to an overdiagnosis of this condition. To identify the various avenues or phenotypes that can lead to an overdiagnosis of LQTS. Electronic medical records were reviewed for all patients evaluated in Mayo Clinic’s Windland Smith Rice Genetic Heart Rhythm Clinic between July 2000 and March 2021 who arrived with an outside diagnosis of LQTS but were dismissed subsequently as normal. Data was abstracted for patient demographics, clinical characteristics, and cardiac and genetic test results. Overall, 291/1909 (15%) originally diagnosed LQTS patients [174 (60%) female, mean age at first Mayo evaluation 22 ± 14 years, mean QTc of 426 ± 25 ms] were dismissed as either normal (276, 95%) or having a different diagnosis altogether (15, 5%). The main cause of LQTS misdiagnosis was misinterpretation of the QTc in 93 (32%) patients, including a borderline QT, inclusion of the U-wave in QTc calculation, or prolonged QTc associated with exercise training. This was closely followed by a prolonged QTc recorded in the emergency department following vasovagal syncope (n=89 [31%]). Furthermore, 47 patients (16%) were diagnosed because of positive family history of LQTS or SCD but dismissed as normal after the SCD was found to be unrelated to LQTS or the patient was negative for family’s LQTS-associated variant. Forty-seven (16%) patients had a variant of uncertain significance (VUS) in one of the main LQTS genes (KCNQ1, KCNH2, SCN5A), however after evaluation, the variant was demoted to likely benign and/or there was no LQTS phenotype in family members. Knowing that the four main determinants of discordance between a previously rendered diagnosis of LQTS and full diagnostic reversal/removal were misinterpretation of the QTc, vasovagal syncope, family history of LQTS, and a VUS in LQTS-causative genes, awareness and screening strategies can be fine-tuned to reduce this ongoing burden of overdiagnosed LQTS.

Feasibility of electrocardiogram screening in the USA prior to high school sport participation

BackgroundSudden cardiac death in young athletes is a catastrophic event with an incidence of 1:40,000–1:80,000. Pre-participation sport screening utilizes a 14-point targeted evaluation. Recently, some states have added an ECG to the traditional history and physical. ObjectivesThe study describes a large-scale ECG screening program for middle and high school students. The aim is to depict important components, partners, and plans that can be adopted by other municipalities to help prevent sudden cardiac arrest in this population. MethodsIn 2019, Brevard County School Board in Florida mandated ECGs before participation in middle and high school sports. They partnered with a non-profit group that provides ECGs for a $20.00 fee. Volunteer pediatric cardiologists interpreted the ECGs. Results were emailed to participants, and abnormal results received a phone call to ensure appropriate follow-up care. ResultsThere were 5877 ECG screenings between 4/1/19–12/31/19 with 3% (199/5877) abnormal: 30% (60/199) ventricular conduction, 26% (51/199) arrhythmias, 13% (25/199) ventricular hypertrophy/chamber enlargement, 11% (21/199) ST-T abnormalities, 8% (16/199) prolonged QTc, 6% (12/199) WPW syndrome, and 4% (7/199) AV conduction and axis deviation. The incidence of critical heart disease with a risk of sudden cardiac arrest was 0.1% (8/5877) in those with a confirmed final diagnosis: 6 who underwent an ablation procedure for WPW syndrome, 1 with gene-positive long QTc, and 1 with left ventricular hypertrophy who is undergoing genetic evaluation for hypertrophic cardiomyopathy. ConclusionsTo our knowledge, this is the first large school district in Florida to mandate this level of cardiovascular screening. This pilot project demonstrates that large volume ECG screening prior to school sport participation is feasible at a low cost when utilizing appropriate manpower and providing access to follow up-care.

Deep Learning for Detecting and Locating Myocardial Infarction by Electrocardiogram: A Literature Review.

Myocardial infarction is a common cardiovascular disorder caused by prolonged ischemia, and early diagnosis of myocardial infarction (MI) is critical for lifesaving. ECG is a simple and non-invasive approach in MI detection, localization, diagnosis, and prognosis. Population-based screening with ECG can detect MI early and help prevent it but this method is too labor-intensive and time-consuming to carry out in practice unless artificial intelligence (AI) would be able to reduce the workload. Recent advances in using deep learning (DL) for ECG screening might rekindle this hope. This review aims to take stock of 59 major DL studies applied to the ECG for MI detection and localization published in recent 5 years, covering convolutional neural network (CNN), long short-term memory (LSTM), convolutional recurrent neural network (CRNN), gated recurrent unit (GRU), residual neural network (ResNet), and autoencoder (AE). In this period, CNN obtained the best popularity in both MI detection and localization, and the highest performance has been obtained from CNN and ResNet model. The reported maximum accuracies of the six different methods are all beyond 97%. Considering the usage of different datasets and ECG leads, the network that trained on 12 leads ECG data of PTB database has obtained higher accuracy than that on smaller number leads data of other datasets. In addition, some limitations and challenges of the DL techniques are also discussed in this review.

Opportunistic screening for asymptomatic left ventricular dysfunction in type 2 diabetes mellitus

BackgroundInternational guidelines recommend natriuretic peptide biomarker-based screening for patients at high heart failure (HF) risk to allow early detection. There have been few reports about the incorporation of screening procedure...

Opportunistic screening for asymptomatic left ventricular dysfunction in type 2 diabetes mellitus.

International guidelines recommend natriuretic peptide biomarker-based screening for patients at high heart failure (HF) risk to allow early detection. There have been few reports about the incorporation of screening procedure to existing clinical practice. To implement screening of left ventricular dysfunction in patients with type 2 diabetes mellitus (DM). A prospective screening study at the DM complication screening centre was performed. Between 2018 and 2019, 1043 patients (age: 63.7±12.4 years; male: 56.3%) with mean glycated haemoglobin of 7.25%±1.34% were recruited. 81.8% patients had concomitant hypertension, 31.1% had coronary artery disease, 8.0% had previous stroke, 5.5% had peripheral artery disease and 30.7% had chronic kidney disease (CKD) stages 3-5. 43 patients (4.1%) had an elevated N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentration above the age-specific diagnostic thresholds for HF, and 43 patients (4.1%) had newly detected atrial fibrillation (AF). The prevalence of elevated NT-proBNP increased with age from 0.85% in patients aged <50 years to 7.14% in those aged 70-79 years and worsening kidney function from 0.43% in patients with CKD stage 1 to 42.86% in CKD stage 5. In multivariate logistic regression, male gender (OR: 3.67 (1.47-9.16), p = 0.005*), prior stroke (OR: 3.26 (1.38-7.69), p = 0.007*), CKD (p<0.001*) and newly detected AF (OR: 7.02 (2.65-18.57), p<0.001*) were significantly associated with elevated NT-proBNP. Among patients with elevated NT-proBNP, their mean left ventricular ejection fraction (LVEF) was 51.4%±14.7%, and 45% patients had an LVEF <50%. NT-proBNP and ECG screening could be implemented with relative ease to facilitate early detection of cardiovascular complication and improve long-term outcomes.

J wave syndromes in patients with spinal and bulbar muscular atrophy

BackgroundMales with X-linked recessive spinobulbar muscular atrophy (SBMA) are reported to die suddenly and a Brugada electrocardiography (ECG) pattern may be present. A hallmark of this pattern is the presence of ST segment elevations in right precordial leads associated with an increased risk of sudden cardiac death.ObjectiveWe aimed to detect subtle myocardial abnormalities using ECG and cardiovascular magnetic resonance imaging (CMR) in patients with SBMA.Methods30 SBMA patients (55.7 ± 11.9 years) and 11 healthy male controls underwent 12-lead ECGs were recorded using conventional and modified chest leads. CMR included feature-tracking strain analysis, late gadolinium enhancement and native T1 and T2 mapping.ResultsTestosterone levels were increased in 6/29 patients. Abnormal ECGs were recorded in 70%, consisting of a Brugada ECG pattern, early repolarization or fragmented QRS. Despite normal left ventricular ejection fraction (66 ± 5%), SBMA patients exhibited more often left ventricular hypertrophy as compared to controls (34.5% vs 20%). End-diastolic volumes were smaller in SBMA patients (left ventricular volume index 61.7 ± 14.7 ml/m2 vs. 79.1 ± 15.5 ml/m2; right ventricular volume index 64.4 ± 16.4 ml/m2 vs. 75.3 ± 17.5 ml/m2). Tissue characterization with T1-mapping revealed diffuse myocardial fibrosis in SBMA patients (73.9% vs. 9.1%, device-specific threshold for T1: 1030 ms).ConclusionSBMA patients show abnormal ECGs and structural abnormalities, which may explain an increased risk of sudden death. These findings underline the importance of ECG screening, measurement of testosterone levels and potentially CMR imaging to assess cardiac risk factors.

Free Papers Compiled

BACKGROUND:Schizophrenia is a major mental disorder with a never-ending search for etiology. Ion channel dysfunction is one among the etiologies proposed and various studies have been done on the same (1)(2)(3). Patients with Schizophrenia have a high incidence of Sudden cardiac death, almost three times the risk of general population.Brugada syndrome(4) and QTc prolongation (5) are a few among the cardiac disorders characterized by ion channel dysfunction (6) and can also lead to Sudden cardiac death (7). Identifying these two abnormalities in ECG can help prevent Sudden cardiac deaths especially in schizophrenia patients. This study aims to identify the prevalence of these abnormalities in ECG of patients with Schizophrenia and the socio demographic, clinical profile and drug treatment were correlated with the prevalence of these abnormalities. The importance of routine ECG screening in patients with Schizophrenia should be understood as well.AIMS:To estimate the prevalence of Brugada pattern ECG and QTc prolongation in Patients with Schizophrenia and their correlation with demographic factors, clinical and co-morbid factors and use of antipsychotics.MATERIALS AND METHODS:Convenience sampling of 160 cases with Schizophrenia fulfilling the study inclusion and exclusion criteria were recruited after obtaining IRB approval and informed consent. The sociodemographic factors, clinical and comorbid profile, treatment profile were recorded and analysed. A 12 lead ECG recording was taken for these patients. Screening of ECG for Brugada pattern and QTc prolongation were done. Prevalence was calculated in percentage. Bivariate and multivariate analysis were done to assess the association between variables.

Assesment of Normal ECG Percentiles and Cardiac Rhythm Problems through 12-Lead ECG Screening in School-Age Children

Introduction: Electrocardiography (ECG) is an important non-invasive examination used for the diagnosis of cardiovascular diseases and rhythm problems for nearly hundred years. Many studies showed the important effect of age and gender on electrocardiographic tracings and studies were made to form ECG data normal for age groups. The number of studies on this subject is quite low in children. The aim of this study was to evaluate the standard percentile values of ECG measurement and the prevalence of cardiac rhythm disorders in school children aged 6-18 in our region. Material and Method: 2154 students who were randomly selected from eight elementary, secondary and high schools in Malatya city center were included in the study and informed consent form was taken from their families. Using MAC 2000 (GE Healthcare, Milwaukee, USA) device capable of taking digital ECG record, ECG records with standard 12 derivations were taken for all participating children. ECG records of all children were examined by the same pediatric cardiologists. Using 24 hour Holter ECG and echocardiography, advanced evaluation was performed for the children with problems detected in ECG records. Results: Pathology was detected in the ECG of 110 out of a total of 2154 children whose ECG records were examined. Average age of 2044 children without detected conduction and rhythm disorder was 11.4±2.8 and 56.8% (n=1149) were female. In addition to the heart rate, PR, QT and QTc interval and QRS time, R/S ratio was also checked manually in V1, V2 and V6 precordial derivations together with QTc, P, QRS and T axis for the children participating in the study. These eleven parameters were compared to the other studies in literature. Mean QTc interval was detected below 440 milliseconds in all age groups (6-9, 9-13, 13-18). Mean heart rate per minute was found higher in all age groups in our study compared to other studies. Thus mean QTc interval was found lower than the other studies although QT distance was similar. Conclusion: Data of this study is important for the detection of normal ECG percentiles and the prevalence of rhythm problems in children and would guide other future studies on this subject.

Analysis of Athlete QT Intervals by Age: Fridericia and Hodges Heart Rate Correction Methods Outperform the Bazett's Method for Athlete ECG Screening

Analysis of Athlete QT Intervals by Age: Fridericia and Hodges Heart Rate Correction Methods Outperform the Bazett's Method for Athlete ECG Screening

S-ICD screening revisited: do passing vectors sometimes fail?

Pre-implant ECG screening is performed to ensure that S-ICD recipients have at least one suitable sensing vector, yet cardiac over-sensing remains the commonest cause of inappropriate shock therapy in the S-ICD population. One explanation would be the presence of dynamic variations in ECG morphology that result in variations in vector eligibility. Adult ICD patients had a 24-h ambulatory ECG performed using a digital Holter positioned to record all three S-ICD vectors. Using an S-ICD simulator, automated screening was then performed at one-minute intervals. In vectors with a mean vector score>100 (the accepted value for a passing vector when screened on a single occasion), the percentage of all screening assessments that passed, eligible vector time (EVT), was calculated. EVT was compared statistically to QRS duration, corrected time to peak T (pTc) and mean vector score. Ambulatory monitoring was performed in 14 patients (mean age 63.7 ± 5.2 years, 71.4% male) with 42 vectors analysed. In 19 vectors the mean vector score was>100. Within this "passing" cohort EVT varied between 42.7% and 100%. In 7/19 (37%) the EVT was<75%. A negative correlation was found between QRS duration and EVT (Pearson correlation -.60, p=.007). No correlation was found between EVT and mean vector score or pTc. Vector eligibility is dynamic. When "passing" vectors are subjected to repeated screening, 37% are found to be ineligible, more than a quarter of the time. Further investigation is required to determine the clinical significance of these findings.

Cost-Effectiveness of Portable Electrocardiogram for Screening Cardiovascular Diseases at a Primary Health Center in Ahmedabad District, India.

Background: District Health Authority in Ahmedabad, Gujarat has introduced Project Lifeline, 12-lead portable ECG devices across all primary health centers (PHC) in the district to screen cardiac abnormalities among high-risk and symptomatic adults for providing primary management and proper timely referral. The prime purpose of the study was to assess the cost-effectiveness of portable ECG for the screening of cardiovascular diseases (CVD) among high-risk and symptomatic adults at the PHC in Ahmedabad, Gujarat.Methods: Cost-effective analysis was conducted using a societal perspective. An incremental costing approach was adapted, and cost-effectiveness analysis was done using a decision-analytic model. We surveyed 73 patients who screened positive for cardiac abnormality, documented the type of ECG abnormalities, and diagnosed CVD. The program cost was obtained from the implementers. Transition probabilities were derived from primary data supported by expert opinion for the intervention arm, while a systematic search of the literature was undertaken to derive transition probabilities for the control arm.Results: The ECG screening at PHC saves 2.90 life years at an incremental cost of 89.97 USD (6657.47 INR), yielding a cost-effectiveness ratio of 31.07 USD (2,299.06 INR) per life-year saved, which is below the willingness to pay threshold. The budget impact analysis was also performed. Results are sensitive to the relative risk reduction associated with the non-participation and the cost of initial screening.Conclusion: Cost-effectiveness analysis clearly shows that the facility to screen cardiac abnormality at the PHC level is highly recommended for high-risk adults and symptomatic cases.

Atrial fibrillation detected at screening is not a benign condition: outcomes in screen-detected versus clinically detected atrial fibrillation. Results from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study

AimsIt is unknown whether screen-detected atrial fibrillation (AF) carries cardiovascular risks similar to clinically detected AF. We aimed to compare clinical outcomes between individuals with screen-detected and clinically detected incident...

Diagnostic yield and cost analysis of electrocardiographic screening in Swiss paediatric athletes

ObjectivesAthletes performing sports on high level are at increased risk for sudden cardiac death. This includes paediatric athletes, even though data on screening strategies in this age group remain scarce. This study aimed to assess electrocardiogram interpretation criteria in paediatric athletes and to evaluate the cost of screening. MethodsNational, multicentre, retrospective, observational study on 891 athletes of paediatric age (<18 years) evaluated by history, physical examination and 12-lead electrocardiogram. The primary outcome measure was abnormal electrocardiogram findings according to the International Recommendations for Electrographic Interpretation in Athletes. The secondary outcome measure was cost of screening. Results19 athletes (2.1%) presented abnormal electrocardiogram findings requiring further investigations, mainly abnormal T-wave inversion. These 19 athletes were predominantly males, performing endurance sports with a mean volume of 10 weekly hours for a mean duration of 6 years of training. Further investigations did not identify any relevant pathology. All athletes were cleared for competition with regular follow-up. Total costs of the screening were 108,860 USD (122 USD per athlete). ConclusionsOur study using the International Recommendations for Electrographic Interpretation in Athletes identified a low count of abnormal findings in paediatric athletes, yet raising substantially the cost of screening. Hence, the utility of electrocardiogram-inclusive screening of paediatric athletes remains to be elucidated by longitudinal data.

Abstract 9176: Quarterly versus Annual ECG Screening for Atrial Fibrillation in Older Chinese (AF-CATCH): A Prospective, Randomised, Controlled Trial

Introduction: Screening for atrial fibrillation before symptoms manifested and subsequent initiation of oral anticoagulants (OACs), could prevent stroke and death. The most cost-effective strategy to screen atrial fibrillation in high-risk population aged 65 and over remains unknown. Methods: We performed a randomised controlled trial that compares different screening frequencies of 30-second single-lead ECG (AliveCor® Heart Monitor) in the detection of atrial fibrillation in Chinese residents (≥65 years old) in 5 community health centres in Shanghai. Only participants without atrial fibrillation history and atrial fibrillation rhythm at baseline were eligible for inclusion in the trial. Participants were randomised in a 1:1 ratio into annual (G1) and quarterly screening (G2) groups: the quarterly screening group was further randomised in a 3:1 ratio into subgroups of quarterly screening (G2-1) and quarterly screening PLUS (G2-2, ECG weekly for 1-month then quarterly). The primary outcome was the detection rate of atrial fibrillation. The intention-to-treat analysis was performed for all randomised patients who had at least one ECG recording during follow-up. This trial was registered at ClinicalTrials.gov, number NCT02990741. Results: Between April 17, 2017, and June 26, 2018, a total of 8240 participants were randomised into G1 (n=4120), G2-1 (n=3090) and G2-2 (n=1030), with a mean of 1.6, 3.5 and 5.2 ECG records respectively during a median of 2.1 years follow-up (13,284 person-years). 73 incident cases of atrial fibrillation occurred: 26 in G1 (4.1/1000 person-years) and 47 in G2 (6.7/1000 person-years; hazard ratio with G1, 1.71; 95% confidence interval [CI] 1.06-2.76; P =0.03). 40 incident cases were detected in G2-1 (7.2/1000 person-years; hazard ratio with G1, 1.83; 95% CI 1.12-3.00; P =0.02) and 7 in G2-2 (4.8/1000 person-years; hazard ratio with G1, 1.24; 95% CI 0.54-2.86; P =0.61). No significant difference was noted between G2-1 and G2-2 (hazard ratio with G2-1, 0.68; 95% CI 0.30-1.52; P =0.35). Conclusions: Quarterly 30-second single-lead ECG screening significantly increased the detection rate of incident atrial fibrillation, additional weekly screening in the first month did not yield added predictive value.

Abstract 10291: Electrocardiographic Markers of Subclinical Myocardial Dysfunction in Patients with Severe Obesity and Normal Ejection Fraction. The FatWest Study

Introduction: Patients with severe obesity are predisposed to left ventricular (LV) myocardial dysfunction and increased myocardial oxygen (O 2 ) demand despite preserved ejection fraction (EF). Hypothesis: To test whether electrocardiography (ECG) may be used to identify patients with severe obesity that have myocardial dysfunction despite normal EF by echocardiography. Methods: In the prospective FatWest (Bariatric Surgery on the West Coast of Norway) study, 116 severely obese patients (41±11 years, 75% women, body mass index [BMI] 41.7±4.6 kg/m 2 , 57% with hypertension, EF 61±5%) underwent 12-lead ECG and echocardiography before a Roux-en-Y gastric bypass surgery. Low LV mechanics was defined as global longitudinal strain (GLS) below the median, and high myocardial O 2 demand as LV mass-wall stress-heart rate product above the median value. ECG markers of atrial (P axis and duration) and ventricular (QRS axis and duration, T axis, QRS-T angle, time to intrinsicoid deflection (ID), and corrected QT (QTc)) de- and repolarization were analyzed. Results: Median GLS was -15.5%, and median myocardial O 2 demand 1.47 x106 g kdyne/cm 2 bpm. Patients with low GLS had longer QRS, time to ID and QTc duration, while those with high myocardial O 2 demand had increased P axis and duration (all p&lt;0.05). In multivariate regression analyses, longer QTc was associated with lower GLS (R 2 0.24) and increased P axis with higher myocardial O 2 demand (R 2 0.21) independent of age, gender, BMI and hypertension (all p&lt;0.05). A QTc &gt;435ms and P axis &gt;42° had 70% specificity in detecting low GLS and high myocardial O 2 demand (Figure). Conclusion: In severely obese patients, ECG measures of atrial activation and delayed ventricular repolarization were independently associated with low LV myocardial function and high myocardial O 2 demand. ECG screening before bariatric surgery may identify patients in whom advanced echocardiography is warranted.

Abstract 9213: Effect of Ai-Enabled Ecg Screening for Low Ef in Patients With Different Socioeconomic Status

Introduction: Asymptomatic LV systolic dysfunction is often underdiagnosed, leading to missed opportunities for treatment. In a recently completed pragmatic RCT, an AI algorithm performed on the ECGs ordered as part of routine practice increased early diagnosis of low EF. The current study aimed to understand whether the effectiveness of the AI algorithm integrated into routine care differed by the socioeconomic status of the patient. Methods: The main findings of the RCT were previously published. Clinicians in the intervention group had access to AI results (i.e., a positive or negative screening result, with positive results indicating a high likelihood of low EF). When a positive result was found, clinicians in the intervention group received an alert that encouraged them to order TTE if considered clinically appropriate. Clinicians in the control group did not have access or received alerts. Area deprivation index (ADI) was used to measure area-level social determinants of health. This study included 16,992 patients (control 8,225; intervention: 8,767) who had ECG performed for any indications between 8/5/2019 and 3/31/2020, no prior HF, and a valid address to derive ADI. The primary endpoint was a new diagnosis of EF≤50% within 3 months. Results: The mean age was 60.5±17.6 y. AI increased the diagnosis of low EF in the overall cohort (OR 1.42 [1.13, 1.78], p=0.01). The magnitude of benefit was greater in patients with higher socioeconomic status, e.g., living in an area that is less deprived (OR 1.88 [1.16, 3.05]), with higher median income, lower poverty rate, higher education level, better housing conditions, and higher proportion of white-collar workers, although the interaction was not statistically significant (Figure). Conclusions: AI enables early diagnosis of low EF and the magnitude of benefit might be numerically greater in patients with higher socioeconomic status, possibly due to variations in access to or referral for subsequent testing.

Abstract 12234: Is Maintenance of a Subcutaneous Implantable Cardioverter-Defibrillator a Feasible Option in Hypertrophic Cardiomyopathy Patients With Left Bundle Branch Block After Septal Myectomy?

Introduction: Subcutaneous implantable cardioverter-defibrillators (SICD) are effective for sudden death (SCD) prevention in patients (pts) with hypertrophic cardiomyopathy (HCM). Pre-implant ECG screening to evaluate R and T wave sensing is done to decrease the risk of inappropriate shocks (IAS). Pts who undergo septal myectomy are at high risk of developing left bundle branch block (LBBB) that could potentially result in SICD T wave oversensing (TWOS). Objective: We describe 6 cases of pts with SICD and septal myectomy to understand the risks and benefits of maintaining SICD therapy in this cohort. Methods: We performed a retrospective cohort study of all pts with HCM who underwent SICD implantation and septal myectomy from 2013 to 2021. Results: Six pts with HCM underwent both SICD implantation and myectomy. Post myectomy ECGs for all pts show LBBB with QRS between 137 to 166 ms. Four of these pts were implanted prior to myectomy. The average time to myectomy after SICD was 1.3 years. Three out of the four pts have had no IAS or TWOS since myectomy. One patient experienced TWOS with 2 IAS 4 months after myectomy. The sensing vector was changed from primary to alternate with no further TWOS for the last 6 years. The remaining two pts underwent SICD implantation after myectomy, both of whom screened “OK” using the manual screening tool prior to implant. Neither patient has experienced IAS. One patient displayed episodes of TWOS and underwent vector change with no TWOS for the last 5 years. At the time of recent SICD generator replacement, he was screened using the automated programmer software and failed screening in all 3 vectors (Figure 1). Conclusions: This series demonstrates that maintenance of SICD is a viable option for SCD prevention in young pts who develop LBBB after septal myectomy. With close monitoring and vector adjustment, IAS and TWOS can be avoided. Further larger studies are necessary to assess the long-term risk of TWOS and IAS in this unique population.

Abstract 12176: Oral Anticoagulant Therapy Following Single-Lead ECG Screening Among Older Patients With Atrial Fibrillation: The VITAL-AF Trial

Introduction: A substantial proportion of patients with atrial fibrillation do not take oral anticoagulants (OAC). Point of care ECG testing at primary care visits may prompt reassessment of OAC eligibility in patients with AF. Methods: VITAL-AF (NCT035115057) was a cluster-randomized trial of AF screening using single-lead handheld electrocardiograms within 16 primary care practices affiliated with Massachusetts General Hospital. The goal of VITAL-AF was to screen for undiagnosed AF. For pragmatic reasons the trial included all individuals aged ≥ 65 years, including those with an established diagnosis of AF. We evaluated screening uptake among prevalent AF patients in the screening arm, OAC initiation among both screening and control patients with prevalent AF, and OAC initiation by screening result (adjusted for stroke/bleed risk factors compared to all patients not screened). OAC use was identified using electronic health record medication lists during the 1-year prior to and following a patient’s study index visit. Results: Prevalent AF was present in 2,250 patients (75% on OAC) in the screening arm and 2,343 patients (76% on OAC) in the control arm. 90% of patients in the screening arm were screened at least once during the study period (mean 2.4 times screened). 31.5% had a “Possible AF” and 17.2% had an “Unclassified” automated algorithm screening result during their first screening encounter (40.1% “Possible AF” and 27.4% “Unclassified” during any encounter). Overall, OAC initiation was similar among prevalent AF patients from the screening arm and control arm ( Table ). OAC initiation was higher among screened patients who had a “Possible AF” automated result (Adjusted Odds Ratio 1.14, 95% CI: 1.05-1.24). Conclusions: Point of care cardiac rhythm assessment was not associated with significant changes in the use of OAC in patients with a history of AF. However, screened patients not on OAC who had a positive single-lead ECG were more likely to initiate OAC.

ECG evaluation in 11 949 Italian teenagers: results of screening in secondary school.

AimThere is lack of evidence regarding the screening role of ECG for sudden cardiac death (SCD) prevention. Our aim was to evaluate the prevalence of ECG abnormalities among teenagers according to sport participation and competitive status.MethodsEleven thousand nine hundred and forty-nine Italian pupils from 179 secondary schools (13–19 years) were consecutively enrolled. ECG abnormalities were divided into minor and major. Medical history, clinical examination and sport activity information were acquired. Further evaluations were suggested in case of major ECG abnormalities. Follow-up was performed at 2 years.ResultsN = 1945 (16%) pupils had ECG abnormalities. Major ECG abnormalities were detected in 13% of the cohort, minor in 34%. ECG abnormalities were more common in nonathletes compared with athletes. A diagnosis of cardiac disease was reached in 25 (1.6%) of the pupils with major ECG abnormalities.ConclusionECG abnormalities are common among young populations and more prevalent in nonathletes. Among pupils with major ECG abnormalities 1.6% had a cardiac disease diagnosis. Our results are in line with the data supporting ECG screening in the general young population.