Outcomes Associated With Giant Coronary Artery Aneurysms After Kawasaki Disease: A Single-Center United States Experience.

OBJECTIVE: To determine the long-term outcomes among a cohort of patients with Kawasaki disease (KD) and a history of giant coronary artery aneurysms (CAA) at a single US center. RESULTS: There were 60 patients with KD and giant CAAs identified between 1989 and 2023. The majority of patients were male (71.7%) with median age at diagnosis of 0.9 years (0.2-13.3). Patients were followed for a median of 11 years, up to 34.5 years. MACE occurred in 13 (21.7%) patients at a median of 1.4 years (0.04-22.6) after KD diagnosis. The 10-, 20-, and 30-year MACE-free rates were 75%, 75%, and 60%. Patients with maximal CA z-scores ≥20 or bilateral CAA were more likely to have MACE. During follow-up, 26.7% of CAA regressed to normal luminal diameter at a median of 3.6 years (0.6-12.0). The 10-, 20- and 30-year likelihood of CA regression to normal luminal diameter was 36%, 46%, and 46%. CONCLUSIONS: Over 30 years, MACE occurred in nearly 22% of patients, more often in those with bilateral CAA or CA z-scores ≥20. Despite regression to normal luminal diameter in over 25% of CAA, patients with a history of KD-associated giant CAA require ongoing surveillance for cardiac complications, even years after the initial disease.

"But for the blind spot": Accuracy and diagnostic performance of smart watch cardiac features in pediatric patients.

BACKGROUND: The Apple Watch™ (AW) offers heart rate (HR) tracking by photoplethysmography (PPG) and single-lead electrocardiographic (ECG) recordings. The accuracy of AW-HR and diagnostic performance of AW-ECGs among children during both sinus rhythm and arrhythmias have not been explored. OBJECTIVE: The purposes of this study were to assess the accuracy of AW-HR measurements compared to gold standard modalities in children during sinus rhythm and arrhythmias and to identify non-sinus rhythms using AW-ECGs. METHODS: Subjects ≤18 years wore an AW during (1) telemetry admission, (2) electrophysiological study (EPS), or (3) exercise stress test (EST). AW-HRs were compared to gold standard modality values. Recorded AW-ECGs were reviewed by 3 blinded pediatric electrophysiologists. RESULTS: Eighty subjects (median age 13 years; interquartile range 1.0-16.0 years; 50% female) wore AW (telemetry 41% [n = 33]; EPS 34% [n = 27]; EST 25% [n = 20]). A total of 1090 AW-HR measurements were compared to time-synchronized gold standard modality HR values. Intraclass correlation coefficient (ICC) was high 0.99 (0.98-0.99) for AW-HR during sinus rhythm compared to gold standard modalities. ICC was poor comparing AW-HR to gold standard modality HR in tachyarrhythmias (ICC 0.24-0.27) due to systematic undercounting of AW-HR values. A total of 126 AW-ECGs were reviewed. Identification of non-sinus rhythm by AW-ECG showed sensitivity of 89%-96% and specificity of 78%-87%. CONCLUSIONS: We found high levels of agreement for AW-HR values with gold standard modalities during sinus rhythm and poor agreement during tachyarrhythmias, likely due to hemodynamic effects of tachyarrhythmias on PPG-based measurements. AW-ECGs had good sensitivity and moderate specificity in identification of non-sinus rhythm in children.

Longitudinal echocardiographic parameters before and after pacemaker placement in congenital complete heart block.

BACKGROUND: Congenital complete heart block (CCHB) is seen in 1:15,000-1:20,000 live births, with risk of left ventricular (LV) dysfunction or dilated cardiomyopathy in 7%-23% of subjects. OBJECTIVE: The purpose of this study was to investigate serial changes in LV size and systolic function in paced CCHB subjects to examine the effect of time from pacemaker on echocardiographic parameters. METHODS: Single-center retrospective cohort analysis of paced CCHB subjects was performed. Echocardiographic data were collected before and after pacemaker placement. Linear mixed effect regression of left ventricular end-diastolic dimension (LVEDD) z-score, left ventricular shortening fraction (LVSF), and left ventricular ejection fraction (LVEF) was performed, with slopes compared before and after pacemaker placement. RESULTS: Of 114 CCHB subjects, 52 had echocardiographic data before and after pacemaker placement. Median age at CCHB diagnosis was 0.6 [interquartile range 0.0-3.5] years; age at pacemaker placement 3.4 [0.5-9.0] years; and pacing duration 10.8 [5.2-13.7] years. Estimated LVEDD z-score was 1.4 at pacemaker placement and decreased -0.08 per year (95% confidence interval [CI] -0.12 to -0.04; P = .002) to 0.2 (95% CI -0.3 to +0.3) 15 years postplacement. Estimated LVSF decreased -1.1% per year (95% CI -1.7% to -0.6%; P <.001) from 6 months prepacemaker placement to 34% (95% CI 32%-37%) 4 years postplacement. There was no significant change in LVSF between 4 and 15 years postplacement. Estimated LVEF did not change significantly after pacemaker placement, with estimated LVEF 59% (95% CI 55%-62%) 15 years postplacement. CONCLUSION: In 52 paced CCHB subjects, estimated LVEDD z-score decreased significantly after pacemaker placement, and estimated LVSF and LVEF remained within normal limits at 15 years postpacemaker placement.

Electrocardiographic Findings in Genotype-Positive and Non-sarcomeric Children with Definite Hypertrophic Cardiomyopathy and Subclinical Variant Carriers.

In children with hypertrophic cardiomyopathy (HCM), the genotype-phenotype association of abnormal electrocardiographic (ECG) features in the backdrop of gene positivity has not been well described. This study aimed to describe the abnormal ECG findings in children with HCM harboring who have genetic variants and determine the association with major adverse cardiac events (MACE). We retrospectively analyzed 81 variants-positive, phenotype-positive (V+P+), 66 variant-positive, phenotype-negative (V+P-), and 85 non-sarcomeric subjects. We analyzed ECG findings and clinical outcomes in the three groups of subjects. Repolarization abnormalities (ST and T wave changes) and pathologic Q waves were the most common abnormalities in variant and non-sarcomeric subjects. The V+P+ group showed higher occurrence of ST segment changes and T wave abnormalities compared to V+P- group. Independent predictors of MACE included ST segment changes (OR 3.54, CI 1.20-10.47, p = 0.022). T wave changes alone did not predict outcome (OR 2.13, CI 0.75-6.07, p = 0.157), but combined repolarization abnormalities (ST+T changes) were strong predictors of MACE (OR 5.84, CI 1.43-23.7, p = 0.014) than ST segment changes alone. Maximal wall z score by echocardiography was a predictor of MACE (OR 1.21, CI 1.07-1.37, p = 0.002). Despite the presence of significant myocardial hypertrophy (z score > 4.7), voltage criteria for LVH were much less predictive. In the non-sarcomeric group, RVH was significantly associated with MACE (OR 3.85, CI 1.08-13.73, p = 0.038). These abnormal ECG findings described on the platform of known genetic status and known myocardial hypertrophy may add incremental value to the diagnosis and surveillance of disease progression in children with HCM. Select ECG findings, particularly repolarization abnormalities, may serve as predictors of MACE in children.

Risk Stratification in Pediatric Wolff-Parkinson-White: Practice Variation Among Pediatric Cardiologists and Electrophysiologists.

BACKGROUND: Published guidelines provide recommendations for risk stratification in pediatric Wolff-Parkinson-White (WPW). There are no data on provider concordance with these guidelines. We hypothesized that significant practice variation exists between pediatric cardiologists (PC) and electrophysiologists (EP). METHOD: The records of all patients, age 8 to 21 years, with a new ECG diagnosis of WPW between 1/1/2013 and 12/31/2018, from a single center, were retrospectively reviewed. Subjects were categorized on the basis of symptoms and resting ECG findings as one of the following: asymptomatic intermittent WPW, asymptomatic persistent WPW, or symptomatic WPW. The performance and results of diagnostic testing, including Holter monitor, event monitor, exercise stress test (EST), and electrophysiology study (EPS), were recorded. The primary outcome was concordance with published guidelines. A secondary outcome was documentation of a discussion of sudden cardiac death (SCD) risk. RESULTS: 615 patient encounters were analyzed in 231 patients with newly diagnosed WPW pattern on ECG (56% male; mean age at diagnosis 13.9 ± 2.5 years). EP were observed to have a significantly higher rate of guideline concordance than PC (95% vs. 71%, p < 0.001). There was significant practice variation between PC and EP in the documentation of a discussion of SCD risk: 96% in EP vs. 39% in PC (p < 0.001). CONCLUSION: Significant practice variation exists in the non-invasive and invasive risk stratification of pediatric WPW, with lower concordance to published guidelines amongst PC, when compared to EP. This report highlights the need to promote awareness of current WPW guidelines in the pediatric cardiology community at large.

A Pilot Randomized Clinical Trial of Intranasal Oxytocin to Promote Weight Loss in Individuals With Hypothalamic Obesity.

Context: Hypothalamic obesity is a rare, treatment-resistant form of obesity. In preliminary studies, the hypothalamic hormone oxytocin (OXT) has shown promise as a potential weight loss therapy. Objective: To determine whether 8 weeks of intranasal OXT (vs 8 weeks of placebo) promotes weight loss in children, adolescents, and young adults with hypothalamic obesity. Methods: This randomized, double-blind, placebo-controlled, crossover pilot trial (NCT02849743), conducted at an outpatient academic medical center, included patients aged 10 to 35 years with hypothalamic obesity from hypothalamic/pituitary tumors. Participants received intranasal OXT (Syntocinon, 40 USP units/mL, 4 IU/spray) vs excipient-matched placebo, 16 to 24 IU 3 times daily at mealtimes. Weight loss attributable to OXT vs placebo and safety (adverse events) were assessed. Results: Of 13 individuals randomized (54% female, 31% pre-pubertal, median age 15.3 years, IQR 13.3-20.6), 10 completed the entire study. We observed a nonsignificant within-subject weight change of -0.6 kg (95% CI: -2.7, 1.5) attributable to OXT vs placebo. A subset (2/18 screened, 5/13 randomized) had prolonged QTc interval on electrocardiography prior to screening and/or in both treatment conditions. Overall, OXT was well-tolerated, and adverse events (epistaxis and nasal irritation, headache, nausea/vomiting, and changes in heart rate, blood pressure, and QTc interval) were similar between OXT and placebo. In exploratory analyses, benefits of OXT for anxiety and impulsivity were observed. Conclusion: In this pilot study in hypothalamic obesity, we did not detect a significant impact of intranasal OXT on body weight. OXT was well-tolerated, so future larger studies could examine different dosing, combination therapies, and potential psychosocial benefits.

Assessing Effective Practices and Barriers to Creating School and Community Partnerships for a Sudden Cardiac Death Prevention Program: A National Project ADAM® study.

OBJECTIVES: Project ADAM (Automated Defibrillators in Adam's Memory) is a national collaborative to improve outcomes for out-of-hospital sudden cardiac arrest. Given Project ADAM's expansion, we sought to identify effective methods to partner with community leaders and understand barriers to engagement. Our aim was to establish effective practices to guide affiliates and optimize site operations and partnerships. METHODS: We conducted a survey of all Project ADAM sites in 2020. Medical Directors and Program Coordinators were included for generalizability. The survey consisted of 20 questions covering the domains of communication, goals for partner organizations, partnership barriers, staff time commitments, and Project ADAM program needs. RESULTS: Thirty-one members responded: 14 Medical Directors and 17 Program Coordinators. E-mail was the predominant method to initiate (58%) and maintain (87%) contact with partner organizations, though telephone (21%) and in-person visits (14%) were common for initiating contact. Presentations at school board, Emergency Medical Services, and athletic director meetings and student/family testimonials were powerful engagement tools. Barriers to partnership varied, revolving around limited school budgets, overburdened staff, and Covid-19. Limited time, difficulty coordinating schedules, and lack of dedicated resources were common challenges for Project ADAM sites. Only 36% of Medical Directors receive institutional recognition of Project ADAM effort. CONCLUSIONS: Project ADAM's partnership with community stakeholders creates unique opportunities and challenges. Optimal communication methods should be identified early for each school, with regular interaction for long-term success. Institutional recognition of Project ADAM efforts may boost success. Additionally, the Covid-19 pandemic created numerous challenges and may spur operational changes.

Targeting nucleic acid-based therapeutics to tumors: Challenges and strategies for polyplexes.

The current medical reality of cancer gene therapy is reflected by more than ten approved products on the global market, including oncolytic and other viral vectors and CAR T-cells as ex vivo gene-modified cell therapeutics. The development of synthetic antitumoral nucleic acid therapeutics has been proceeding at a lower but steady pace, fueled by a plethora of alternative nucleic acid platforms (from various antisense oligonucleotides, siRNA, microRNA, lncRNA, sgRNA, to larger mRNA and DNA) and several classes of physical and chemical delivery technologies. This review summarizes the challenges and strategies for tumor-targeted nucleic acid delivery. Focusing primarily on polyplexes (polycation complexes) as nanocarriers, delivery options across multiple barriers into tumor cells are illustrated.

Incidence of morbidity and mortality in a cohort of congenital complete heart block patients followed over 40 years.

BACKGROUND: Congenital complete heart block (CCHB) is seen in 1:15,000-20,000 births and commonly requires pacemaker placement by young adulthood. There is limited understanding of cardiac morbidity and mortality. OBJECTIVE: The purpose of this study was to determine the long-term incidence of cardiac morbidity and mortality in subjects with CCHB and identify associated risk factors. METHODS: Retrospective cohort analysis of subjects with CCHB at Children's Hospital of Philadelphia between 1976 and 2018 was performed. The primary outcome was a composite of death, left ventricular systolic dysfunction, heart failure, cardiomyopathy, or cardiac resynchronization therapy (CRT). Cox proportional hazard models assessed independent risk factors for the primary outcome and its components (death, heart failure and/or cardiomyopathy, CRT). RESULTS: One-hundred fourteen subjects (58% female; median age at last visit 15.2 years) were included. Eighty-eight (77%) underwent pacemaker implantation (median age at placement 1.9 years; interquartile range [IQR] 0.1-8.0 years). Twenty-six subjects (23%) reached the primary outcome; 7 (6%) died and 14 (12%) were diagnosed with heart failure and/or cardiomyopathy. Median time from diagnosis to primary outcome was 3.1 years (IQR 0.0-10.8 years). There were no significant associations between age at diagnosis <1 year (hazard ratio [HR] 1.5; 95% confidence interval [CI] 0.6-3.9), fetal diagnosis (HR 2.3; 95% CI 0.96-5.6), or maternal antibody positivity (HR 2.4; 95% CI 0.9-6.6) and the primary outcome. Fetal diagnosis had a higher associated hazard of heart failure and/or cardiomyopathy (HR 4.5; 95% CI 1.3-15.0). CONCLUSION: In 114 subjects with CCHB, 23% reached the composite outcome of cardiac morbidity and mortality, with no significant association between age at diagnosis, fetal diagnosis, and maternal antibody status with composite cardiac morbidity and mortality.

Compression-Only Versus Rescue-Breathing Cardiopulmonary Resuscitation After Pediatric Out-of-Hospital Cardiac Arrest.

BACKGROUND: There are conflicting data regarding the benefit of compression-only bystander cardiopulmonary resuscitation (CO-CPR) compared with CPR with rescue breathing (RB-CPR) after pediatric out-of-hospital cardiac arrest (OHCA). OBJECTIVES: This study sought to test the hypothesis that RB-CPR is associated with improved neurologically favorable survival compared with CO-CPR following pediatric OHCA, and to characterize age-stratified outcomes with CPR type compared with no bystander CPR (NO-CPR). METHODS: Analysis of the CARES registry (Cardiac Arrest Registry to Enhance Survival) for nontraumatic pediatric OHCAs (patients aged ≤18 years) from 2013-2019 was performed. Age groups included infants (<1 year), children (1 to 11 years), and adolescents (≥12 years). The primary outcome was neurologically favorable survival at hospital discharge. RESULTS: Of 13,060 pediatric OHCAs, 46.5% received bystander CPR. CO-CPR was the most common bystander CPR type. In the overall cohort, neurologically favorable survival was associated with RB-CPR (adjusted OR: 2.16; 95% CI: 1.78-2.62) and CO-CPR (adjusted OR: 1.61; 95% CI: 1.34-1.94) compared with NO-CPR. RB-CPR was associated with a higher odds of neurologically favorable survival compared with CO-CPR (adjusted OR: 1.36; 95% CI: 1.10-1.68). In age-stratified analysis, RB-CPR was associated with better neurologically favorable survival versus NO-CPR in all age groups. CO-CPR was associated with better neurologically favorable survival compared with NO-CPR in children and adolescents, but not in infants. CONCLUSIONS: CO-CPR was the most common type of bystander CPR in pediatric OHCA. RB-CPR was associated with better outcomes compared with CO-CPR. These results support present guidelines for RB-CPR as the preferred CPR modality for pediatric OHCA.

Sudden Death in the Young: Information for the Primary Care Provider.

There are multiple conditions that can make children prone to having a sudden cardiac arrest (SCA) or sudden cardiac death (SCD). Efforts have been made by multiple organizations to screen children for cardiac conditions, but the emphasis has been on screening before athletic competition. This article is an update of the previous American Academy of Pediatrics policy statement of 2012 that addresses prevention of SCA and SCD. This update includes a comprehensive review of conditions that should prompt more attention and cardiology evaluation. The role of the primary care provider is of paramount importance in the evaluation of children, particularly as they enter middle school or junior high. There is discussion about whether screening should find any cardiac condition or just those that are associated with SCA and SCD. This update reviews the 4 main screening questions that are recommended, not just for athletes, but for all children. There is also discussion about how to handle post-SCA and SCD situations as well as discussion about genetic testing. It is the goal of this policy statement update to provide the primary care provider more assistance in how to screen for life-threatening conditions, regardless of athletic status.

Can Pediatric Practitioners Correctly Interpret Electrocardiograms?

OBJECTIVES: To assess the impact of participation in an educational presentation on electrocardiogram (ECG) interpretation in children on pediatric practitioners' ability to accurately interpret ECGs. STUDY DESIGN: Pediatric healthcare providers at a pediatric clinic with >65 000 visits/year were eligible to participate. A 1-hour ECG educational module that provided a systematic approach to ECG interpretation was presented to 8 providers who consented (6 pediatricians, 2 pediatric nurse practitioners). A test on 11 ECGs (normal, normal-variant, and abnormal ECGs) was given before and 2 weeks after the educational module. Outcomes included correct interpretation of each ECG as normal or abnormal and correct identification of specific ECG findings. Data analysis was descriptive and included χ2 and Student t test. RESULTS: Mean score (SD) for correct interpretation of ECGs as normal or abnormal improved from 35% (48%) (95% CI 25.0-45.4) to 77% (42%) (95% CI 68.3-86.2) after the ECG educational module (P < .001). Mean (SD) pretest score for correct identification in the normal ECG category improved from 45% (50%) (95% CI 28.9-61.1) to 68% (47%) (95% CI 52.3-82.7) (P= .003). In the abnormal ECG category, correct identification improved from 31% (47%) (95% CI 17.6-44.9) to 83% (5%) (95% CI 72.4-94.3) after the module (P < .001). CONCLUSIONS: Education of pediatric practitioners on ECG interpretation significantly improves their ability to distinguish normal from abnormal and to identify specific abnormalities. Limitations included small sample size and short-term follow-up.

Electrocardiograms in Healthy North American Children in the Digital Age.

BACKGROUND: Interpretation of pediatric ECGs is limited by lack of accurate sex- and race-specific normal reference values obtained with modern technology for all ages. We sought to obtain contemporary digital ECG measurements in healthy children from North America, to evaluate the effects of sex and race, and to compare our results to commonly used published datasets. METHODS: Digital ECGs (12-lead) were retrospectively collected for children ≤18 years old with normal echocardiograms at 19 centers in the Pediatric Heart Network. Patients were classified into 36 groups: 6 age, 2 sex, and 3 race (white, black, and other/mixed) categories. Standard intervals and amplitudes were measured; mean±SD and 2nd/98th percentiles were determined by age group, sex, and race. For each parameter, multivariable analysis, stratified by age, was conducted using sex and race as predictors. Parameters were compared with 2 large pediatric ECG data sets. RESULTS: Among ECGs from 2400 children, significant differences were found by sex and race categories. The corrected QT interval in lead II was greater for girls compared with boys for age groups ≥3 years (P≤0.03) and for whites compared with blacks for age groups ≥12 years (P<0.05). The R wave amplitude in V6 was greater for boys compared with girls for age groups ≥12 years (P<0.001), for blacks compared with white or other race categories for age groups ≥3 years (P≤0.006), and greater compared with a commonly used public data set for age groups ≥12 years (P<0.0001). CONCLUSIONS: In this large, diverse cohort of healthy children, most ECG intervals and amplitudes varied by sex and race. These differences have important implications for interpreting pediatric ECGs in the modern era when used for diagnosis or screening, including thresholds for left ventricular hypertrophy.

The Second Annual Think Tank on Prevention of Sudden Cardiac Death in the Young: Developing a rational, reliable, and sustainable national health care resource. A report from the Cardiac Safety Research Consortium.

Sudden cardiac death in the young (SCDY) spans gender, race, ethnicity, and socioeconomic class. The loss of any pediatric patient is a matter of national and international public health concern, and focused efforts should be aimed at preventing these burdensome tragedies. Prepared by members of the Cardiac Safety Research Consortium, this White Paper summarizes and reports the dialogue at the second Think Tank related to the issues and the proposed solutions for the development of a national resource for screening and prevention of SCDY. This Think Tank, sponsored by the Cardiac Safety Research Consortium and the United States Food and Drug Administration, convened on February 18, 2016, in Miami, FL, to identify and resolve the barriers that prevent early identification of patients at risk for SCDY. All potential stakeholders including national and international experts from industry, medicine, academics, engineering, and community advocacy leaders had an opportunity to share ideas and collaborate.

International recommendations for electrocardiographic interpretation in athletes.

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly over the last decade; pushed by a growing body of scientific data that both tests proposed criteria sets and establishes new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington, to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

Prevention of sudden cardiac death in the young: Developing a rational, reliable, and sustainable national health care resource. A report from the Cardiac Safety Research Consortium.

This White Paper, prepared by members of the Cardiac Safety Research Consortium, discusses important issues regarding sudden cardiac death in the young (SCDY), a problem that does not discriminate by gender, race, ethnicity, education, socioeconomic level, or athletic status. The occurrence of SCDY has devastating impact on families and communities. Sudden cardiac death in the young is a matter of national and international public health, and its prevention has generated deep interest from multiple stakeholders, including families who have lost children, advocacy groups, academicians, regulators, and the medical industry. To promote scientific and clinical discussion of SCDY prevention and to germinate future initiatives to move this field forward, a Cardiac Safety Research Consortium-sponsored Think Tank was held on February 21, 2015 at the US Food and Drug Administration's White Oak facilities, Silver Spring, MD. The ultimate goal of the Think Tank was to spark initiatives that lead to the development of a rational, reliable, and sustainable national health care resource focused on SCDY prevention. This article provides a detailed summary of discussions at the Think Tank and descriptions of related multistakeholder initiatives now underway: it does not represent regulatory guidance.

International criteria for electrocardiographic interpretation in athletes: Consensus statement.

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly, advanced by a growing body of scientific data and investigations that both examine proposed criteria sets and establish new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington (USA), to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.