Sudden Cardiac Death in Athletes

Catastrophic injuries and exertional medical events in lacrosse among youth, high school and collegiate athletes: longitudinal surveillance over four decades (1982-2020)

OBJECTIVE

To determine the incidence rates (IRs) of catastrophic injuries and exertional medical events in lacrosse athletes.

METHODS

Catastrophic injuries and exertional medical events in lacrosse in the US among youth or amateur, high school and college athletes were analysed from the National Center for Catastrophic Sport Injury Research (NCCSIR) database from 1982/83 to 2019/20. Frequencies, IRs per 100,000 athlete-seasons (AS) with 95% confidence intervals (CIs), and incidence rate ratios (IRRs) with 95% CIs were calculated. Participation data were gathered from the National Federation of State High School Associations (NFHS), National Collegiate Athletic Association (NCAA) and USA Lacrosse.

RESULTS

Sixty-nine catastrophic events (16 youth or amateur, 36 high school and 17 college; 84% male) occurred in US lacrosse from 7/1/1982 to 6/30/2020. Thirty-six percent of all incidents were fatal. The overall IR was 0.5 per 100,000 AS (95% CI: 0.4-0.7). There were 15 cases of non-traumatic sudden cardiac arrests (SCAs) and 15 incidents of commotio cordis. Fatality rates from SCA and commotio cordis decreased 95% (IRR = 0.05; 95% CI: 0, 0.2) from 1982/83-2006/07 to 2007/08-2019/20. Incidence rates were higher for collegiate versus high school 1982/83-2019/20 (IRR = 3.2; 95% CI: 1.8, 5.7) and collegiate versus youth 2005/06-2019/20 (IRR = 8.0; 95% CI: 3.0, 21.4) level. Contact with a stick or ball (41%) and contact with another player (20%) were the primary mechanisms of injury.

CONCLUSIONS

The incidence of catastrophic events during lacrosse was higher among collegiate than high school or youth athletes. SCA from an underlying cardiac condition or from commotio cordis was the most common catastrophic event. Fatality rates from catastrophic injuries have declined significantly over the study period, perhaps driven by protective measures adopted by lacrosse governing bodies.

Resuscitation on the field of play: a best-practice guideline from Resuscitation Council UK

Sudden cardiac arrest (SCA) is the leading cause of sudden death in athletes during high-level, organised sport. Patient-related and event-related factors provide an opportunity for rapid intervention and the potential for high survival rates. The aim of this consensus was to develop a best-practice guideline for dedicated field-of-play medical teams responding to SCA during an organised sporting event. A task-and-finish group from Resuscitation Council UK identified a stakeholder group of relevant experts and cardiac arrest survivors in March and April 2022. Together, they developed a best-practice guideline using the best available evidence. A public consultation period further refined the guideline before it was finalised in December 2023. Any sudden collapse, without rapid recovery during sporting activity, should be considered an SCA until proven otherwise. Field-of-play medical teams should be empowered to access the collapsed athlete as soon as possible and perform initial essential interventions in situ. This includes a suggested minimum of three cycles of cardiopulmonary resuscitation and defibrillation in persistent shockable rhythms while other aspects of advanced life support are initiated. There should be careful organisation and practice of the medical response, including plans to transport athletes to dedicated facilities for definitive medical care. This best-practice guideline complements, rather than supersedes, existing resuscitation guidelines. It provides a clear approach to how to best treat an athlete with SCA and how to organise the medical response so treatments are delivered effectively and optimise outcomes.

Heritability of sudden cardiac death in Thoroughbred racehorses

BACKGROUND

Sudden cardiac death (SCD) is an important cause of exercise-associated fatalities in Thoroughbred racehorses. Equine deaths share similarities with fatalities in human athletes that result from inherited cardiac disease. Whilst genetic causes have been postulated in horses, these have not been confirmed and heritability of SCD has not previously been estimated in Thoroughbred racehorses.

OBJECTIVES

To determine the heritability of SCD in a sample population of Thoroughbred racehorses.

STUDY DESIGN

Retrospective case-control study.

METHODS

Steward and post-mortem reports of Thoroughbred racehorses in Australia between 2007 and 2020 were reviewed to identify horses with SCD. Control horses were randomly selected from races in which SCD occurred or from races on the date of the case fatality. A five-generation integrated pedigree chart was collected for each horse. Estimates of heritability were obtained using an animal model in the ASReml-R program with variance components estimated assuming SCD was normally distributed, and on the logit transformed scale. Inbreeding coefficients were calculated and the risk of producing SCD-affected progeny was calculated for stallions that sired ≥5 individuals in the case-control population.

RESULTS

Ninety-three horses with SCD and 465 control horses were identified. Heritability on the underlying scale was 0.15 ± 0.09 (logit animal) and 0.24 ± 0.12 (normal animal). Inbreeding coefficients were not significantly different between groups. Of the 16 first generation sires that appeared ≥5 times in the case-control data set, two sires more frequently produced affected progeny (OR 7.95-10.41).

MAIN LIMITATIONS

Challenges in definitively confirming SCD may lead to misclassification of some cases. Some control horses may have not been exposed to environmental influences of SCD. Case numbers are low and the studied population may not represent the entire Thoroughbred genetic pool.

CONCLUSION

The heritability of SCD in this population was relatively low. However, individual stallions appear more likely to produce affected progeny. Further studies are required to understand the genetic and environmental influences that contribute to disease expression.

Results From the Big Ten COVID-19 Cardiac Registry: Impact of SARS-COV-2 on Myocardial Involvement

OBJECTIVE

COVID-19 has been associated with myocardial involvement in collegiate athletes. The first report from the Big Ten COVID-19 Cardiac Registry (Registry) was an ecological study that reported myocarditis in 37 of 1597 athletes (2.3%) based on local clinical diagnosis. Our objective was to assess the relationship between athlete and clinical characteristics and myocardial involvement.

DESIGN

Cross-sectional study.

SETTING

We analyzed data from 1218 COVID-19 positive Big Ten collegiate athletes who provided informed consent to participate in the Registry.

PARTICIPANTS

1218 athletes with a COVID-19-positive PCR test before June 1, 2021.

ASSESSMENT OF INDEPENDENT VARIABLES

Demographic and clinical characteristics of athletes were obtained from the medical record.

MAIN OUTCOME MEASURES

Myocardial involvement was diagnosed based on local clinical, cardiac magnetic resonance (CMR), electrocardiography, troponin assay, and echocardiography. We assessed the association of clinical factors with myocardial involvement using logistic regression and estimated the area under the receiver operating characteristic (ROC) curve.

RESULTS

25 of 1218 (2.0%) athletes met criteria for myocardial involvement. The logistic regression model used to predict myocardial involvement contained indicator variables for chest pain, new exercise intolerance, abnormal echocardiogram (echo), and abnormal troponin. The area under the ROC curve for these indicators was 0.714. The presence of any of these 4 factors in a collegiate athlete who tested positive for COVID-19 would capture 55.6% of cases. Among noncases without missing data, 86.9% would not be flagged for possible myocardial involvement.

CONCLUSION

Myocardial involvement was infrequent. We predicted case status with good specificity but deficient sensitivity. A diagnostic approach for myocardial involvement based exclusively on symptoms would be less sensitive than one based on symptoms, echo, and troponin level evaluations. Abnormality of any of these evaluations would be an indication for CMR.

International Criteria for Reporting Study Quality for Sudden Cardiac Arrest/Death Tool

BACKGROUND

Studies reporting on the incidence of sudden cardiac arrest and/or death (SCA/D) in athletes commonly lack methodological and reporting rigor, which has implications for screening and preventative policy in sport. To date, there are no tools designed for assessing study quality in studies investigating the incidence of SCA/D in athletes.

METHODS AND RESULTS

The International Criteria for Reporting Study Quality for Sudden Cardiac Arrest/Death tool (IQ-SCA/D) was developed following a Delphi process. Sixteen international experts in sports cardiology were identified and invited. Experts voted on each domain with subsequent moderated discussion for successive rounds until consensus was reached for a final tool. Interobserver agreement between a novice, intermediate, and expert observer was then assessed from the scoring of 22 relevant studies using weighted and unweighted κ analyses. The final IQ-SCA/D tool comprises 8 domains with a summated score of a possible 22. Studies are categorized as low, intermediate, and high quality with summated IQ-SCA/D scores of ≤11, 12 to 16, and ≥17, respectively. Interrater agreement was "substantial" between all 3 observers for summated IQ-SCA/D scores and study categorization.

CONCLUSIONS

The IQ-SCA/D is an expert consensus tool for assessing the study quality of research reporting the incidence of SCA/D in athletes. This tool may be used to assist researchers, reviewers, journal editors, and readers in contextualizing the methodological quality of different studies with varying athlete SCA/D incidence estimates. Importantly, the IQ-SCA/D also provides an expert-informed framework to support and guide appropriate design and reporting practices in future SCA/D incidence trials.

Prevalence of Abnormal Cardiovascular Magnetic Resonance Findings in Athletes Recovered from COVID-19 Infection: A Systematic Review and Meta-Analysis

Background: Competitive sports and high-level athletic training result in a constellation of changes in the myocardium that comprise the 'athlete's heart'. With the spread of the COVID-19 pandemic, there have been concerns whether elite athletes would be at higher risk of myocardial involvement after infection with the virus. This systematic review and meta-analysis evaluated the prevalence of abnormal cardiovascular magnetic resonance (CMR) findings in elite athletes recovered from COVID-19 infection. Methods: The PubMed, Cochrane and Web of Science databases were systematically search from inception to 15 November 2023. The primary endpoint was the prevalence of abnormal cardiovascular magnetic resonance findings, including the pathological presence of late gadolinium enhancement (LGE), abnormal T1 and T2 values and pericardial enhancement, in athletes who had recovered from COVID-19 infection. Results: Out of 3890 records, 18 studies with a total of 4446 athletes were included in the meta-analysis. The pooled prevalence of pathological LGE in athletes recovered from COVID-19 was 2.0% (95% CI 0.9% to 4.4%, I2 90%). The prevalence of elevated T1 and T2 values was 1.2% (95% CI 0.4% to 3.6%, I2 87%) and 1.2% (95% CI 0.4% to 3.7%, I2 89%), respectively, and the pooled prevalence of pericardial involvement post COVID-19 infection was 1.1% (95% CI 0.5% to 2.5%, I2 85%). The prevalence of all abnormal CMR findings was much higher among those who had a clinical indication of CMR. Conclusions: Among athletes who have recently recovered from COVID-19 infection, there is a low prevalence of abnormal CMR findings. However, the prevalence is much higher among athletes with symptoms and/or abnormal initial cardiac screening. Further studies and longer follow up are needed to evaluate the clinical relevance of these findings and to ascertain if they are associated with adverse events.

The relationship between workload and exercise-induced cardiac troponin elevations is influenced by non-obstructive coronary atherosclerosis

The relationship between exercise-induced troponin elevation and non-obstructive coronary artery disease (CAD) is unclear. This observational study assessed non-obstructive CAD's impact on exercise-induced cardiac Troponin I (cTnI) elevation in middle-aged recreational athletes. cTnI levels of 40 well-trained recreational athletes (73% males, 50 ± 9 years old) were assessed by a high-sensitive cTnI assay 24 h before, and at 3 and 24 h following two high-intensity exercises of different durations; a cardiopulmonary exercise test (CPET), and a 91-km mountain bike race. Workload was measured with power meters. Coronary computed tomography angiography was used to determine the presence or absence of non-obstructive (<50% obstruction) CAD. A total of 15 individuals had non-obstructive CAD (Atherosclerotic group), whereas 25 had no atherosclerosis (normal). There were higher post-exercise cTnI levels following the race compared with CPET, both at 3 h (77.0 (35.3-112.4) ng/L vs. 11.6 (6.4-22.5) ng/L, p < 0.001) and at 24 h (14.7 (6.7-16.3) vs. 5.0 (2.6-8.9) ng/L, p < 0.001). Absolute cTnI values did not differ among groups. Still, the association of cTnI response to power output was significantly stronger in the CAD versus Normal group both at 3 h post-exercise (Rho = 0.80, p < 0.001 vs. Rho = -0.20, p = 0.33) and 24-h post-exercise (Rho = 0.87, p < 0.001 vs. Rho = -0.13, p = 0.55). Exercise-induced cTnI elevation was strongly correlated with exercise workload in middle-aged athletes with non-obstructive CAD but not in individuals without CAD. This finding suggests that CAD influences the relationship between exercise workload and the cTnI response even without coronary artery obstruction.

Sudden cardiac death in a young male endurance athlete

Sudden cardiac death (SCD) is a rare yet devastating event that can occur in young athletes. Although hypertrophic obstructive cardiomyopathy is the most common cause of SCD, some other genetic abnormalities have been identified as proarrhythmic. However, there is not routine screening for these other genetic abnormalities. Furthermore, consumption of caffeine, stimulant medication, or prolonged exercise can potentiate the underlying arrhythmic potential. In the event of SCD, advanced cardiac life support (ACLS) should be performed immediately and exactly. The authors present a case of an otherwise healthy young male who collapsed during a marathon and could not be resuscitated despite aggressive measures. After aggressive resuscitative efforts, the patient ultimately expired. A postmortem autopsy revealed no cardiac structural abnormalities, and the cause of death was determined to be cardiac arrhythmia of undetermined etiology. Postmortem genetic testing revealed a heterozygous variation in calcium voltage-gated channel auxiliary subunit beta 2 (CACNB2), a gene associated with arrhythmia and calcium channelopathy. Toxicology showed therapeutic levels of amphetamine. This case highlights the eminent risk of cardiac death in young athletes with proarrhythmic genetic variations, especially in the setting of endurance sport.

Plasma Advanced Glycation End Products and Dicarbonyl Compounds Are Not Associated with Coronary Atherosclerosis in Athletes

PURPOSE

Coronary atherosclerosis is the leading cause of sudden death among athletes >35 yr old, but current cardiovascular risk prediction algorithms have not been validated for athletes. Advanced glycation end products (AGE) and dicarbonyl compounds have been associated with atherosclerosis and rupture-prone plaques in patients and ex vivo studies. The detection of AGE and dicarbonyl compounds might be a novel screening tool for high-risk coronary atherosclerosis in older athletes.

METHODS

Concentrations of three different AGE and the dicarbonyl compounds methylglyoxal, glyoxal, and 3-deoxyglucosone were measured in plasma with ultraperformance liquid chromatography tandem mass spectrometry in athletes from the Measuring Athletes' Risk of Cardiovascular Events 2 study cohort. Coronary plaques, plaque characteristics (calcified, noncalcified or mixed), and coronary artery calcium (CAC) scores were assessed with coronary computed tomography, and potential associations with AGE and dicarbonyl compounds were analyzed using linear and logistic regression.

RESULTS

A total of 289 men were included (60 [quartiles 1-3 = 56-66] yr old, body mass index = 24.5 [22.9-26.6] kg·m -2 ), with a weekly exercise volume of 41 (25-57) MET-hours. Coronary plaques were detected in 241 participants (83%), with a dominant plaque type of calcified plaques in 42%, noncalcified plaques in 12% and mixed plaques in 21%. No AGE or dicarbonyl compounds were associated with total number of plaques or any of the plaque characteristics in adjusted analyses. Similarly, AGE and dicarbonyl compounds were not associated with CAC score.

CONCLUSIONS

Concentrations of plasma AGE and dicarbonyl compounds do not predict the presence of coronary plaques, plaque characteristics or CAC scores, in middle-age and older athletes.

Sudden Cardiac Death in Athletes: Consensuses and Controversies

Exercise is widely considered beneficial for cardiovascular health. However, on rare occasions, athletes experience sudden cardiac death without any preceding symptoms. The devastating nature of these events necessitates us to understand the underlying causes. In younger athletes (age <35), the underlying causes are usually hereditary/genetic, whereas in older athletes (age >35), coronary artery disease is prevalent. Sudden cardiac death in athletes can occur regardless of the presence of any structural abnormality in the heart. Despite divergence between guidelines, the majority of cardiology societies recommend at least taking a comprehensive history and performing physical examinations for initial screening for all athletes. This article reviews the consensuses and controversies regarding the incidence, causes, and prevention of sudden cardiac death in athletes.

Comparison of four electrocardiographic criteria for the detection of cardiac abnormalities in Singapore athletes

Introduction

Sudden cardiac death in athletes is a rare occurrence, the most common cause being hypertrophic cardiomyopathy, which increases the risk of sustained ventricular tachycardia or ventricular fibrillation. Most of these young athletes are asymptomatic prior to the cardiac arrest. Several electrocardiogram criteria such as the European Society of Cardiology group 2 Criteria changes, Seattle Criteria, Refined Criteria, and most recently the 2017 International Criteria, have sought to improve the accuracy of identifying these at-risk athletes during pre-participation screening while minimising unnecessary investigations for the majority of athletes at low risk.We aimed to compare the above four criteria in our Singapore athlete population to identify which criterion performed the best in detecting cardiac abnormalities on echocardiography.

Method

Out of 1,515 athletes included in Changi General Hospital, Singapore registry between June 2007 and June 2014, the electrocardiograms of 270 athletes with further cardiac investigations were analysed. We compared the above four electrocardiographic criteria to evaluate which performed best for detecting cardiac abnormalities on echocardiography in our Southeast Asian athlete population.

Results

The European Society of Cardiology, Seattle, Refined and 2017 International Criteria had a sensitivity of 20%, 0%, 20% and 5%, respectively; a specificity of 64%, 93%, 84% and 97%, respectively; a positive predictive value of 4%, 0%, 9% and 11%, respectively; and a negative predictive value of 91%, 92%, 93% and 93%, respectively for detecting abnormalities on echocardiography.

Conclusion

The latest 2017 International Criteria performed the best as it had the highest specificity and positive predictive value, joint highest negative predictive value, and lowest false positive rate.

Sudden cardiac death in the adolescent population: a narrative review

Background

Death from unexpected circulatory arrest within 60 min of onset of symptom is known as sudden cardiac death (SCD). In spite of the advancement in treatment and prevention strategies, SCD remains the most common cause of death worldwide especially in the young.

Main body

This review focuses on highlighting how different cardiovascular diseases contribute to SCD. We discuss the clinical symptoms that the patient experience prior to sudden cardiac arrest and the treatment strategies including pharmacological and surgical treatment.

Conclusions

We conclude that since there are many causes of SCD and very few treatment options, prevention strategies, early detection, and resuscitation of those at greatest risk is important.

Arrhythmogenic Cardiomyopathy and Athletes - A Dangerous Relationship

Arrhythmogenic cardiomyopathy (ACM) is a disease characterized by a progressive replacement of myocardium by fibro-adipose material, predisposing to ventricular arrhythmias (VA) and sudden cardiac death (SCD). Its prevalence is estimated at 1:2000 to 1:5000, with a higher incidence in males, and clinical onset is usually between the 2nd and 4th decade of life. The prevalence of ACM in SCD victims is relatively high, making it one of the most common etiologies in young patients with SCD, especially if they are athletes. Cardiac events occur more frequently in individuals with ACM who participate in competitive sports and/or high-intensity training. In effect, exercise activity can worsen RV function in cases of hereditary ACM. Estimating the incidence of SCD caused by ACM in athletes remains challenging, being reported frequency ranging from 3-20%. Here, we review the potential implications of exercising on the clinical course of the classical genetic form of ACM, as well as the diagnostic tools, risk stratification, and the different therapeutic tools available for managing ACM.

Preparticipation Screening of Athletes: The Prevalence of Positive Family History

Sudden cardiac death (SCD) is a leading cause of death among athletes, and those with a positive family history (FH) of SCD and/or cardiovascular disease (CVD) may be at increased risk. The primary objective of this study was to assess the prevalence and predictors of positive FH of SCD and CVD in athletes using four widely used preparticipation screening (PPS) systems. The secondary objective was to compare the functionality of the screening systems. In a cohort of 13,876 athletes, 1.28% had a positive FH in at least one PPS system. Multivariate logistic regression analysis identified the maximum heart rate as significantly associated with positive FH (OR = 1.042, 95% CI = 1.027-1.056, p < 0.001). The highest prevalence of positive FH was found using the PPE-4 system (1.20%), followed by FIFA, AHA, and IOC systems (1.11%, 0.89%, and 0.71%, respectively). In conclusion, the prevalence of positive FH for SCD and CVD in Czech athletes was found to be 1.28%. Furthermore, positive FH was associated with a higher maximum heart rate at the peak of the exercise test. The findings of this study revealed significant differences in detection rates between PPS protocols, so further research is needed to determine the optimal method of FH collection.

Analysis of differential proteins between non-capacitated and capacitated boar sperm and verification of the effect of phosphofructokinase on capacitation

The objective of this study was to analyze the differences in the proteins in non-capacitated and capacitated boar sperm and to identify the functions of the differential proteins and key capacitation proteins of boar sperm before and after capacitation. Transwell chambers were used to separate capacitated sperm proteins using a unique polycarbonate membrane. Meanwhile, isotopic tags for relative and absolute quantification combined with LC‒MS/MS analysis were used for quantitative determination of differential proteins. Through the comparative analysis of different databases, 475 different proteins were identified in non-capacitated sperm and capacitated sperm, of which 303 were significantly upregulated and 172 were significantly downregulated. These differentially-expressed proteins are mainly involved in redox processes, cell biosynthesis processes and cell aromatic compound metabolism biological processes. They also participate in the signaling pathways of phosphorylation, ketone synthesis and degradation, most of which interact to varying degrees. Among these differentially-expressed proteins, phosphofructokinase attracted our attention as a potential capacitated protein. We further verified that phosphofructokinase can promote boar sperm capacitation by immunoblotting.

Cardiac cycle timing intervals in university varsity athletes

Cardiac cycle timing events in varsity athletes serve an important function for baseline assessment but are not reported in the literature. The purpose of this study was to characterise the cardiac cycle timing intervals and contractility parameters in university-level varsity athletes. 152 males and 93 females were assessed using a non-invasive seismocardiography cardiac sensor attached to the sternum for 1-minute. Shorter isovolumic relaxation time (IVRT), systolic time, mitral valve open to E-wave (MVO to E) time, rapid ejection period (REP), atrial systole to mitral valve closure (AS to MVC) time, and diastolic performance index (IVRT/systolic time) were found in females, while heart rate was lower in males. Varying differences in timing intervals were found between sports. Systolic times were longer in male and female basketball players, while diastole was shortest in male football players, who also had higher heart rates than the other male sport athletes. These results add reference cardiac cycle timing data to the literature and imply that male and female athletes show different cardiac characteristics. Team differences suggest that different training for different sports can result in unique cardiac function changes, however, these appear to be related to the sex of the participants. The addition of these cardiac cycle timing intervals adds a valuable comparative tool to better understand cardiac physiology in the varsity athletic population.HIGHLIGHTS Given the lack of data in the literature on athlete's cardiac cycle timing intervals, we provide normative values for healthy, university varsity athletes, including stratification by sex and sport.Male and female athletes show different cardiac cycle timing intervals, including the systolic and isovolumic relaxation timing intervals.Differences in cardiac cycle timing intervals are also present when comparing different sports.

Pre-race self-reported medical conditions and allergies in 133 641 Comrades ultramarathon (90km) runners - SAFER XXIII

OBJECTIVES

To determine the prevalence of self-reported pre-race chronic medical conditions and allergies in ultramarathon race entrants and to explore if these are associated with an increased risk of race-day medical encounters (MEs).

METHODS

Data from two voluntary open-ended pre-race medical screening questions (Q1 - history of allergies; Q2 - history of chronic medical conditions/prescription medication use) were collected in 133641 Comrades Marathon race entrants (2014-2019). Race-day ME data collected prospectively over 6 years are reported as incidence (per 1000 starters) and incidence ratios (IR: 95%CI's).

RESULTS

Pre-race medical screening questions identified race entrants with a history of chronic medical conditions and/or prescription medication use (6.9%) and allergies (7.4%). The % entrants with risk factors for cardiovascular disease (CVD) was 30% and being older (>45 years) or male (27.5%) were the most frequent CVD risk factors. 0.3% of entrants reported existing CVD. The overall incidence of MEs was 20/1000 race starters. MEs were significantly higher in race entrants reporting a 'yes' to Q1 (allergies) (IR = 1.3; 1.1-1.5) (p = 0.014) or Q2 (chronic medical conditions and/or prescription medication use) (IR = 1.3; 1.1-1.5) (p = 0.0006).

CONCLUSIONS

Voluntary completion of two open-ended questions identified chronic medical conditions and/or prescription medication use in 6.9% and allergies in 7.4% of ultramarathon race entrants. This is lower than that reported for other races that implemented compulsory completion of a more comprehensive pre-screening questionnaire. Despite potential under-reporting, a pre-race self-reported history of chronic medical conditions and allergies was associated with a higher risk of race-day MEs.

Cardiorespiratory fitness, muscle fitness, and physical activity in children with long QT syndrome: A prospective controlled study

Background

In children with congenital long QT syndrome (LQTS), the risk of arrhythmic events during exercise commonly makes it difficult to balance exercise restrictions versus promotion of physical activity. Nevertheless, in children with LQTS, cardiorespiratory fitness, muscle fitness, and physical activity, have been scarcely explored.

Materials and methods

In this prospective, controlled, cross-sectional study, 20 children with LQTS (12.7 ± 3.7 years old) and 20 healthy controls (11.9 ± 2.4 years old) were enrolled. All participants underwent a cardiopulmonary exercise test, a muscular architecture ultrasound assessment, (cross-sectional area on right rectus femoris and pennation angle), a handgrip muscular strength evaluation, and a standing long broad jump test. The level of physical activity was determined using with a waist-worn tri-axial accelerometer (Actigraph GT3X).

Results

Peak oxygen uptake (VO_2peak) and ventilatory anaerobic threshold (VAT) were lower in children with LQTS than in healthy controls (33.9 ± 6.2 mL/Kg/min vs. 40.1 ± 6.6 mL/Kg/min, P = 0.010; 23.8 ± 5.1 mL/Kg/min vs. 28.8 ± 5.5 mL/Kg/min, P = 0.007, respectively). Children with LQTS had lower standing long broad jump distance (119.5 ± 33.2 cm vs. 147.3 ± 36.1 cm, P = 0.02) and pennation angle (12.2 ± 2.4° vs. 14.3 ± 2.8°, P = 0.02). No differences in terms of moderate-to-vigorous physical activity were observed (36.9 ± 12.9 min/day vs. 41.5 ± 18.7 min/day, P = 0.66), but nearly all children were below the WHO guidelines.

Conclusion

Despite similar physical activity level, cardiorespiratory fitness and muscle fitness in children with LQTS were lower than in healthy controls. The origin of this limitation seemed to be multifactorial, involving beta-blocker induced chronotropic limitation, physical and muscle deconditioning. Cardiovascular rehabilitation could be of interest in children with LQTS with significant physical limitation.

Sudden gamer death: non-violent death cases linked to playing video games

BACKGROUND AND AIMS

Internet gaming disorder (IGD) is an emerging problem. Rarely, media reports about people, who have died during playing video games, but thus far no systematic, scientific study is available about the topic. We investigated such cases, looking for common characteristics, connection between gaming and death, and the possible reasons leading to death.

METHODS

Cases were collected through internet search with general keywords, with ones specific to identified cases, and by working along cross references.

RESULTS

24 cases were found: one from 1982, the others between 2002 and 2021. Twenty-three of the victims were male, age ranged from 11 to 40 years. More than half of the cases originated from Southeast Asia, and 12 deaths happened in internet cafes. Gamers played action-rich multiplayer games. In 18 cases the gaming session before death was extremely long (around a day or even several days) with minimal rest. The cause of death was pulmonary embolism in 5 cases, cerebral hemorrhage in 2 cases, most of the rest was presumably due to fatal cardiac arrhythmia.

DISCUSSION

Long sedentary position and dehydration may precipitate thromboembolism, acute blood pressure elevation during gaming may promote cerebral hemorrhage, and several factors (including acute and chronic sleep deprivation, exhaustion, stress) can lead to acute autonomic dysfunction and fatal arrhythmia.

CONCLUSION

Incidence of non-violent death cases linked to playing video games is presumably very low. It mostly occurs in young males and it is often characterized by extremely long gaming time.

Echocardiographic Evaluation of the Athlete's Heart: Focused Review and Update

PURPOSE OF REVIEW

The athlete's heart exhibits unique structural and functional adaptations in the setting of strenuous and repetitive athletic training which may be similarly found in pathologic states. The purpose of this review is to highlight the morphologic and functional changes associated with the athlete's heart, with a focus upon the insights that echocardiography provides into exercise-induced cardiac remodeling.

RECENT FINDINGS

Recent studies are aiming to investigate the long-term effects and clinical consequences of an athlete's heart. The "gray-zone" continues to pose a clinical challenge and may indicate scenarios where additional imaging modalities, or longitudinal follow-up, provide a definitive answer. Echocardiography is likely to remain the first-line imaging modality for the cardiac evaluation of elite athletes. Multimodality imaging combined with outcome and long-term follow-up studies both during training and after retirement in both men and women may help further clarify the remaining mysteries in the coming years.

Novel insights into exhaustive exercise-induced myocardial injury: Focusing on mitochondrial quality control

Regular moderate-intensity exercise elicits benefit cardiovascular health outcomes. However, exhaustive exercise (EE) triggers arrhythmia, heart failure, and sudden cardiac death. Therefore, a better understanding of unfavorable heart sequelae of EE is important. Various mechanisms have been postulated for EE-induced cardiac injury, among which mitochondrial dysfunction is considered the cardinal machinery for pathogenesis of various diseases. Mitochondrial quality control (MQC) is critical for clearance of long-lived or damaged mitochondria, regulation of energy metabolism and cell apoptosis, maintenance of cardiac homeostasis and alleviation of EE-induced injury. In this review, we will focus on MQC mechanisms and propose mitochondrial pathophysiological targets for the management of EE-induced myocardial injury. A thorough understanding of how MQC system functions in the maintenance of mitochondrial homeostasis will provide a feasible rationale for developing potential therapeutic interventions for EE-induced injury.

Effects and Complications of Subcutaneous Implantable Cardioverter-Defibrillator in the Prevention of Sudden Cardiac Death: A Narrative Review

An implantable cardioverter-defibrillator (ICD) is one of those devices that is a big boom for the prevention of sudden deaths due to heart failure. This particular device has been in use for just a couple of years, but its impact in the domain has brought about a considerable change in the way a specific issue of the cardiovascular system is tackled. Although subcutaneous or hypodermic implantable cardioverter-defibrillator (S-ICD) is considered to be a better alternative as far as transvenous implantable cardioverter-defibrillator (TV-ICD) is concerned, the former, being a newer introduction in the market, needs to be assessed in depth to clearly understand its effects and complications. Various types of research have been conducted on the efficacy of this device, and in most of the studies, the supremacy of this device is clearly evident when compared with other devices that are used for the same purpose. Better innovations in subcutaneous or hypodermic implantable cardioverter-defibrillators would enable them to be manufactured in a more efficient and cost-effective way so that a huge lot of people are benefited from this device. This review article is a whole peep into the various studies done in this domain, thereby providing adequate scientific insights about subcutaneous or hypodermic implantable cardioverter-defibrillators in a very simple and comprehensive manner.

Risk Factors for Sudden Death in Athletes, Is There a Role for Screening?

Purpose of Review

Sudden cardiac death (SCD) in a young athlete is an infrequent yet devastating event often associated with substantial media attention. Screening athletes for conditions associated with SCD is a controversial topic with debate surrounding virtually each component including the ideal subject, method, and performer/interpreter of such screens. In fact, major medical societies such as the American College of Cardiology/American Heart Association and the European Society of Cardiology have discrepant recommendations on the matter, and major sporting associations have enacted a wide range of screening policies, highlighting the confusion on this subject. This review seeks to summarize the literature in this area to address the complex and disputed subject of screening young athletes for SCD.

Recent Findings

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause myocarditis, which is one acquired cardiac disease associated with SCD. The coronavirus 2019 (COVID-19) pandemic has therefore resulted in an increased incidence of an otherwise less common condition, providing an expanded dataset for further study of this condition. Recent findings indicate that cardiac complications of athletes with myocardial involvement of SARS-CoV-2 infection are rare. Other contemporary work in SCD screening has been focused on the implementation of various screening protocols and measuring their effectiveness.

Summary

No universal consensus exists for athlete screening for conditions associated with SCD with varying guidelines and protocols across cardiology and sport-specific organizations. No screening program will prevent all SCD; however, small programs managed by physicians familiar with the examination of an athlete that carefully personalize screening to the individual may maximize detection of dangerous cardiac conditions while minimizing false positives.

Surgery for Anomalous Aortic Origin of a Coronary Artery (AAOCA) in Children and Adolescents: A Meta-Analysis

We conducted a systematic review and meta-analysis of the literature to assess the outcomes of surgery for the anomalous aortic origin of a coronary artery in children and young adults (<30 years). Thirteen publications were selected, including a total of 384 patients. Unroofing of the intramural segment was adopted in 92% (95% CI: 81%-98%) of cases, with pooled early and late mortality of 0% (95% CI: 0%-0.3%) and 0.1% (95% CI: 0%-1%), respectively. Reoperation for aortic regurgitation was anecdotal. Surgical management of anomalous aortic origin of coronary arteries can be achieved with excellent results in pediatric patients, but concerns remain about the durability of surgery.

Athlete ECG T-wave abnormality interpretation patterns by non-experts

Background

The presence of T-wave abnormalities (TWA) on an athlete's electrocardiogram (ECG) presents as a diagnostic challenge for physicians. Types of TWA patterns classified as abnormal by inexperienced readers have not been systematically analyzed.

Methods

ECGs from the 2011-2015 National Football League Scouting Combine (initially interpreted by general cardiologists) were retrospectively reviewed by expert sports cardiologists with strict application of the 2017 International Criteria. Patterns of TWA that were altered from the original interpretation were analyzed.

Results

The study included 1643 athletes (mean age 22 years). There was a 67 % reduction in the number of athletes with any TWA (p < 0.001) with 111 ECGs changed to normal. Inferior TWA was the most common interpreted initial ECG abnormality altered followed by anterior and lateral.

Discussion

This analysis revealed an initial high rate of TWA by non-expert readers. Tailored education programs to physicians who interpret athlete ECGs should highlight these specific T-wave patterns. We see this as an opportunity to make more clinicians aware of ECG interpretation guidelines as sports trained cardiologists are mostly self-taught.

Effects and Causes of Detraining in Athletes Due to COVID-19: A Review

Several aspects of systemic alterations caused by the SARS-CoV-2 virus and the resultant COVID-19 disease have been currently explored in the general population. However, very little is known about these particular aspects in sportsmen and sportswomen. We believe that the most important element to take into account is the neuromuscular aspect, due to the implications that this system entails in motion execution and coordination. In this context, deficient neuromuscular control when performing dynamic actions can be an important risk factor for injury. Therefore, data in this review refer mainly to problems derived in the short term from athletes who have suffered this pathology, taking into account that COVID-19 is a very new disease and the presented data are still not conclusive. The review addresses two key aspects: performance alteration and the return to regular professional physical activity. COVID-19 causes metabolic-respiratory, muscular, cardiac, and neurological alterations that are accompanied by a situation of stress. All of these have a clear influence on performance but at the same time in the strategy of returning to optimal conditions to train and compete again after infection. From the clinical evidence, the resumption of physical training and sports activity should be carried out progressively, both in terms of time and intensity.

Rationale and design of the PROspective ATHletic Heart (Pro@Heart) study: long-term assessment of the determinants of cardiac remodelling and its clinical consequences in endurance athletes

Background

Exercise-induced cardiac remodelling (EICR) results from the structural, functional and electrical adaptations to exercise. Despite similar sports participation, EICR varies and some athletes develop phenotypic features that overlap with cardiomyopathies. Training load and genotype may explain some of the variation; however, exercise ‘dose’ has lacked rigorous quantification. Few have investigated the association between EICR and genotype.

Objectives

(1) To identify the impact of training load and genotype on the variance of EICR in elite endurance athletes and (2) determine how EICR and its determinants are associated with physical performance, health benefits and cardiac pathology.

Methods

The Pro@Heart study is a multicentre prospective cohort trial. Three hundred elite endurance athletes aged 14–23 years will have comprehensive cardiovascular phenotyping using echocardiography, cardiac MRI, 12-lead ECG, exercise-ECG and 24-hour-Holter monitoring. Genotype will be determined using a custom cardiomyopathy gene panel and high-density single-nucleotide polymorphism arrays. Follow-up will include online tracking of training load. Cardiac phenotyping will be repeated at 2, 5, 10 and 20 years.

Results

The primary endpoint of the Pro@Heart study is the association of EICR with both training load and genotype. The latter will include rare variants in cardiomyopathy-associated genes and polygenic risk scores for cardiovascular traits. Secondary endpoints are the incidence of atrial and ventricular arrhythmias, physical performance and health benefits and their association with training load and genotype.

Conclusion

The Pro@Heart study is the first long-term cohort study to assess the impact of training load and genotype on EICR.

Trial registration number

NCT05164328; ACTRN12618000716268.

Myocarditis in Athletes Recovering from COVID-19: A Systematic Review and Meta-Analysis

Background: To assess the event rates of myocarditis detected by Cardiac Magnetic Resonance (CMR) in athletes who recovered from COVID-19. Methods: A systematic literature search was performed to identify studies reporting abnormal CMR findings in athletes who recovered from COVID-19. Secondary analyses were performed considering increased serum high sensitivity troponin (hs-Tn) levels and electrocardiographic (ECG) and echocardiographic (ECHO) abnormalities. Results: In total, 7988 athletes from 15 studies were included in the analysis. The pooled event rate of myocarditis was 1% (CI 1–2%), reaching 4% in the sub-group analysis. In addition, heterogeneity was observed (I2 43.8%). The pooled event rates of elevated serum hs-Tn levels, abnormal ECG and ECHO findings were 2% (CI 1–5%), 3% (CI 1–10%) and 2% (CI 1–6%), respectively. ECG, ECHO and serum hs-Tn level abnormalities did not show any correlation with myocarditis. Conclusions: The prevalence of COVID-19-related myocarditis in the athletic population ranges from 1 to 4%. Even if the event rate is quite low, current screening protocols are helpful tools for a safe return to play to properly address CMR studies. Trial registration: the study protocol was registered in the PROSPERO database (registration number: CRD42022300819).

Perspectives in Sports Genomics

Human athletic performance is a complex phenotype influenced by environmental and genetic factors, with most exercise-related traits being polygenic in nature. The aim of this article is to outline some of the challenge faced by sports genetics as this relatively new field moves forward. This review summarizes recent advances in sports science and discusses the impact of the genome, epigenome and other omics (such as proteomics and metabolomics) on athletic performance. The article also highlights the current status of gene doping and examines the possibility of applying genetic knowledge to predict athletes' injury risk and to prevent the rare but alarming occurrence of sudden deaths during sporting events. Future research in large cohorts of athletes has the potential to detect new genetic variants and to confirm the previously identified DNA variants believed to explain the natural predisposition of some individuals to certain athletic abilities and health benefits. It is hoped that this article will be useful to sports scientists who seek a greater understanding of how genetics influences exercise science and how genomic and other multi-omics approaches might support performance analysis, coaching, personalizing nutrition, rehabilitation and sports medicine, as well as the potential to develop new rationale for future scientific investigation.

Circulating miRNA-29b and Sclerostin Levels Correlate with Coronary Artery Calcification and Cardiovascular Events in Maintenance Hemodialysis Patients

Objective

Coronary artery calcification (CAC) is a common complication in end-stage renal disease (ESRD) patients undergoing maintenance hemodialysis (MHD), and the extent of CAC is a predominant predictor of cardiovascular outcomes in MHD patients. In this study, we sought to uncover the relationship between circulating miRNA-29b, sclerostin levels, CAC, and cardiovascular events (CVEs) in MHD patients.

Methods

This study recruited patients receiving MHD for at least three months in the Hainan General Hospital between January 2016 and June 2019, and all patients were followed up 24 months for CVEs. The serum level of sclerostin was determined by enzyme-linked immunosorbent assay (ELISA) and miRNA-29b expression by real-time qPCR (RT-qPCR). All patients received cardiac CT scans to evaluate CAC, and CAC scores were expressed in Agatston units. The MHD patients with CACs <100 were arranged into the CAC (<100) group, those with 100–400 CACs into the CAC (100–400) group, and those with CACs >400 into the CAC (>400) group. Net reclassification index (NRI) and integrated discrimination index (IDI) were calculated to assess the predictive performance of serum sclerostin level for the occurrence of CVEs.

Results

Compared with the CAC (<100) group, the CAC (>400) group had higher proportions of older patients, hypertension and diabetes mellitus patients, longer dialysis duration, higher mean arterial pressure (MAP), higher levels of high-sensitivity C-reactive protein (hs-CRP), alkaline phosphatase (ALP), and phosphate (P < 0.05). It was found that the CAC (100–400) and CAC (>400) groups exhibited higher serum levels of sclerostin but lower levels of miRNA-29b than the CAC (<100) group (P < 0.05) and the CAC (>400) group had a higher level of sclerostin and a lower level of miRNA-29b than the CAC (100–400) group (P < 0.05). The circulating level of miRNA-29b was negatively correlated with the serum level of sclerostin in MHD patients (r = −0.329, P < 0.01). The multivariate logistic regression analysis showed that hs-CRP, phosphate, sclerostin, and miRNA-29b were independent risk factors for CAC in MHD patients (P < 0.05, Table 2). ROC for prediction of CAC by sclerostin yielded 0.773 AUC with 95% CI 0.683–0.864 (P < 0.01). As depicted by Kaplan–Meier curves of CVE incidence in MHD patients according to median sclerostin (491.88 pg/mL) and median miRNA-29b (Ct = 25.15), we found that serum levels of sclerostin and miRNA-29b were correlated with the incidence of CVEs in MHD patients. When a new model was used to predict the incidence of CVEs, NRI 95% CI was 0.60 (0.16–1.03) (P < 0.05) and IDI 95% CI was 0.002 (−0.014 to 0.025) (P < 0.05), suggesting that sclerostin added into the old model could improve the prediction of the incidence of CVEs.

Conclusions

These data suggest that circulating miRNA-29b and sclerostin levels are correlated with CAC and incidence of CVEs in MHD patients. Higher sclerostin and lower miRNA-29b may serve as independent risk factors for the incidence of CVEs in MHD patients.

On-field Emergencies and Emergency Action Plans

Sideline coverage can be an enjoyable experience and provide the opportunity to witness and evaluate an athlete's pathology at the time of injury. While the majority of on-field injury will likely be of low acuity, it is essential to develop an Emergency Action Plan (EAP) to deliver excellent medical care efficiently. The EAP should provide a written, standardized multidisciplinary approach involving key personnel. The EAP should be rehearsed on at least an annual basis and should highlight the initial assessment of the patient while also accounting for the various types of trauma that may occur on the field and appropriate field extrication procedures. As most players who have a true on-field emergency will not return to same-day play, a thorough understanding of how to deliver emergency care and transfer the player to a higher level of care is essential.

Congenital Coronary Artery Anomalies and Sudden Cardiac Death

Coronary artery anomalies (CAAs) are a heterogeneous group of rare congenital diseases whose features and pathophysiological mechanisms are extremely variable, ranging from silent anomalies to sudden cardiac death (SCD) in the most severe cases. Although rare, congenital CAAs confer a high risk of myocardial ischemia and SCD, especially in young, previously "healthy" athletes during or immediately after vigorous exertion. Although some high-risk features that may lead to SCD have been identified, specific pathophysiological mechanisms related to SCD still remain poorly understood. When a CAA is incidentally diagnosed, optimal SCD risk stratification remains challenging, particularly in cases of anomalous aortic origin of a coronary artery arising from the opposite aortic sinus of Valsalva (ACAOS). In recent times, invasive imaging with intravascular ultrasound has gained a role in further identifying high-risk anatomic features; it has been integrated with traditional, non-invasive anatomic imaging evaluations, typically high-quality echocardiography, and cardiac magnetic resonance. Multidisciplinary programs and specific SCD risk scores should be developed in an endeavor to choose the right therapeutic approach, either clinical or interventional/surgical. Intravascular ultrasound is an extremely useful tool to evaluate vessel stenosis, even if prospective studies are still required to further validate this diagnostic strategy. In the present review, we aimed to analyze the pathophysiology and the clinical impact of ACAOS. We also summarized the predominant mechanisms for interference with normal coronary artery function, which might contribute to the onset of life-threatening arrhythmias and SCD.

Physical activity and aerobic fitness in children with inherited cardiac diseases

BACKGROUND

Because of sports and exercise restrictions, children with inherited cardiac disease are at risk of physical deconditioning. Guidelines on sports participation in cardiovascular disease have become less restrictive over time, but their real-life application and behavioural impact have seldom been evaluated in children.

AIMS

We aimed to evaluate adherence to the 2020 European Society of Cardiology guidelines on sports and exercise in children with inherited cardiac arrhythmia and inherited cardiomyopathy; we also sought to evaluate their aerobic fitness, and the behavioural impact of inherited cardiac diseases on physical activity in children.

METHODS

Children aged 6-18 years with inherited cardiomyopathy or inherited cardiac arrhythmia were eligible for this cross-sectional study. Clinical, demographic and qualitative data were analysed.

RESULTS

A total of 32 children were included in the study (mean age 12.7±3.5 years). Most children (81.3%) complied with the 2020 European Society of Cardiology guidelines; they were physically active and had good overall aerobic fitness, with a mean peak oxygen uptake (VO₂) value of 36.5±8.0mL/kg/min (84.0±17.2% of theoretical value). As a result of personal or parental behaviour, some children at risk of sudden cardiac death did not comply with the recommended upper limit of physical activity intensity, whereas others at low risk did not comply with the lower limit.

CONCLUSION

Most children with inherited cardiac arrhythmia or inherited cardiomyopathy complied with current 2020 European Society of Cardiology guidelines on sports cardiology and exercise in cardiovascular disease.

Epidemiology of Football-Related Sudden Cardiac Death in Turkey

Background and Objectives: Sudden cardiac death (SCD), particular among elite footballers, has attracted much attention in recent times. However, limited information exists on football-related SCD in Turkey. Autopsy-based studies of sports-related sudden deaths in Turkey are rare and often have small sample sizes. To address this, this study aimed to determine the population-based incidence and profile of football-related SCD nationally in Turkey. Materials and Methods: Due to a lack of national data on this issue, football-related SCD (non-elite competitive or recreational football) between 1 January 2011, and 31 December 2019 were identified by dual, independent identification and screening of online media reports. Deaths were explored by sex, age group, season, and phase of exercise. Descriptive statistics were utilised. Age-specific mortality rates and proportional mortality rates were calculated. Results: In total, 118 football-related SCD were identified, a crude mortality rate of 0.41 per 100,000 population. All fatalities were males and the mean age was 35.5 years ± 10.4. Those aged 40–49 years recorded the highest mortality rate (0.67/100,000), three times the risk of those aged 50–59 years (RR = 3.1; 95%CI:1.5–6.4). Those aged 30–39 recorded the highest age-specific proportional mortality rate (0.86/1000 deaths). The highest risk occurred while playing football (n = 97; 82.2%), with another 15% of deaths (n = 18) occurring within 1 h of play. Almost all fatalities (n = 113; 95.8%) occurred during participation in recreational football. Conclusions: This study has identified football-related SCD most commonly occurs during recreational football among males aged 30–49 years. It is recommended males of this age participating in recreational football be encouraged to seek pre-participation heart health checks. Given the value of automated external defibrillators (AEDs) in responding to out-of-hospital cardiac arrest, future research should explore the feasibility and effectiveness of AEDs in preventing football-related SCD in Turkey including training of first responders in cardiopulmonary resuscitation and AED use.

ECG Ventricular Repolarization Dynamics during Exercise: Temporal Profile, Relation to Heart Rate Variability and Effects of Age and Physical Health

Periodic repolarization dynamics (PRD) is a novel electrocardiographic marker of cardiac repolarization instability with powerful risk stratification capacity for total mortality and sudden cardiac death. Here, we use a time-frequency analysis approach to continuously quantify PRD at rest and during exercise, assess its dependence on heart rate variability (HRV) and characterize the effects of age (young adults/middle-aged adults/older adults), body mass index (non-overweight/overweight) and cardiorespiratory fitness level (fit/unfit). Sixty-six male volunteers performed an exercise test. RR and dT variabilities (RRV, dTV), as well as the fraction of dT variability unrelated to RR variability, were computed based on time-frequency representations. The instantaneous LF power of dT (PdTV), representing the same concept as PRD, and of its RRV-unrelated component (PdTVuRRV) were quantified. dT angle was found to mostly oscillate in the LF band. Overall, 50-70% of PdTV was linearly unrelated to RRV. The onset of exercise caused a sudden increase in PdTV and PdTVuRRV, which returned to pre-exercise levels during recovery. Clustering analysis identified a group of overweight and unfit individuals with significantly higher PdTV and PdTVuRRV values at rest than the rest of the population. Our findings shed new light on the temporal profile of PRD during exercise, its relationship to HRV and the differences in PRD between subjects according to phenotypic characteristics.

Deep learning analysis of resting electrocardiograms for the detection of myocardial dysfunction, hypertrophy, and ischaemia: a systematic review

The aim of this review was to assess the evidence for deep learning (DL) analysis of resting electrocardiograms (ECGs) to predict structural cardiac pathologies such as left ventricular (LV) systolic dysfunction, myocardial hypertrophy, and ischaemic heart disease. A systematic literature search was conducted to identify published original articles on end-to-end DL analysis of resting ECG signals for the detection of structural cardiac pathologies. Studies were excluded if the ECG was acquired by ambulatory, stress, intracardiac, or implantable devices, and if the pathology of interest was arrhythmic in nature. After duplicate reviewers screened search results, 12 articles met the inclusion criteria and were included. Three articles used DL to detect LV systolic dysfunction, achieving an area under the curve (AUC) of 0.89-0.93 and an accuracy of 98%. One study used DL to detect LV hypertrophy, achieving an AUC of 0.87 and an accuracy of 87%. Six articles used DL to detect acute myocardial infarction, achieving an AUC of 0.88-1.00 and an accuracy of 83-99.9%. Two articles used DL to detect stable ischaemic heart disease, achieving an accuracy of 95-99.9%. Deep learning models, particularly those that used convolutional neural networks, outperformed rules-based models and other machine learning models. Deep learning is a promising technique to analyse resting ECG signals for the detection of structural cardiac pathologies, which has clinical applicability for more effective screening of asymptomatic populations and expedited diagnostic work-up of symptomatic patients at risk for cardiovascular disease.

Regulatory variation within 3’UTR of STAT5A correlates with sudden cardiac death in Chinese populations

Definitive diagnosis to sudden cardiac death (SCD) is often challenging since the postmortem examination on SCD victims could hardly demonstrate an adequate cause of death. It is therefore important to uncover the inherited risk component to SCD. Signal transducer and activators of transcription 5 A (STAT5A) is a member of the STAT family and a transcription factor that is activated by many cell ligands and associated with various cardiovascular processes. In this study, we performed a systematic variant screening on the STAT5A to filter potential functional genetic variations. Based on the screening results, an insertion/deletion polymorphism (rs3833144) in 3'UTR of STAT5A was selected as the candidate variant. A total of 159 SCD cases and 668 SCD matched healthy controls was enrolled to perform a case-control study and evaluate the association between rs3833144 and SCD susceptibility in Chinese populations. Logistic regression analysis showed that the deletion allele of rs3833144 had significantly increased the SCD risk (odds ratio (OR) = 1.54; 95% confidence interval (CI) = 1.18-2.01; P = 0.000955). Further genotype-expression eQTL analysis showed that samples with deletion allele appeared to lower expression of STAT5A, and in silico prediction suggested the local 3 D structure changes of STAT5A mRNA caused by the variant. On the other hand, the bioinformatic analysis presented that promoters of RARA and PTGES3L-AARSD1 could interact with rs3833144, and eQTL analysis showed the higher expression of both genes in samples with deletion allele. Dual-luciferase activity assays also suggested the significant regulatory role of rs3833144 in gene transcription. Our current data thus suggested a possible involvement of rs3833144 to SCD predisposition in Chinese populations and rs3833144 with potential function roles may become a candidate marker for SCD diagnosis and prevention.

Cardiac Imaging in Athlete's Heart: The Role of the Radiologist

Athlete’s heart (AH) is the result of morphological and functional cardiac modifications due to long-lasting athletic training. Athletes can develop very marked structural myocardial changes, which may simulate or cover unknown cardiomyopathies. The differential diagnosis between AH and cardiomyopathy is necessary to prevent the risk of catastrophic events, such as sudden cardiac death, but it can be a challenging task. The improvement of the imaging modalities and the introduction of the new technologies in cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) can allow overcoming this challenge. Therefore, the radiologist, specialized in cardiac imaging, could have a pivotal role in the differential diagnosis between structural adaptative changes observed in the AH and pathological anomalies of cardiomyopathies. In this review, we summarize the main CMR and CCT techniques to evaluate the cardiac morphology, function, and tissue characterization, and we analyze the imaging features of the AH and the key differences with the main cardiomyopathies.

Fatal Events Related to Running Competitions in the Mountains

INTRODUCTION

The few epidemiologic studies published previously about different forms of mountain running (ie, fell running, sky running, and ultratrail running) have not reported on fatal events. This report aims to contribute to the literature on mountain running fatalities, recording and classifying fatal events related to mountain running competitions found in online literature searches over a 12-y period.

METHODS

From 2008 to 2019, searches on mountain sport, mountain races, and newspaper websites were periodically performed, looking for fatal events related to running competitions in the mountains. Data are presented as mean±SD or percentage, as appropriate.

RESULTS

Fifty-one fatal events, involving 45 men (88%) and 6 women (12%), aged 50±11 and 46±6 y, respectively, were recorded in the 2008 to 2019 period in Western Europe. These events occurred during races (n=35; 69%), during training (n=13; 25%), and after races (n=3; 6%); 43% were sudden cardiac death, 32% due to falls (blunt trauma), 16% due to hypothermia, 4% due to both blunt trauma and hypothermia, 4% due to lightning strike injuries, and 2% due to animal attack (injuries from deer).

CONCLUSIONS

Understanding all of the causes of fatal events is necessary to institute preventative efforts and to organize rescues. Preventative efforts should be implemented by race organizers and by athletes themselves, and rescue teams can be trained and equipped to address all of these possible events. The relatively high percentage of sudden cardiac deaths stresses the need for preparticipation cardiovascular screenings. Further longitudinal studies are necessary to better understand the real impact of fatal events on the mountain running population.

Sudden Cardiac Death in Athletes: From the Basics to the Practical Work-Up

Sudden cardiac death in athletes is a relatively rare event, but due to the increasing number of individuals practicing high-performance sports, in absolute terms, it has become an important issue to be addressed. Since etiologies are many and the occurrence is rare, tracing the ideal preparticipation screening program is challenging. So far, as screening tools, a comprehensive clinical evaluation and a simple 12-lead electrocardiogram (ECG) seem to be the most cost-effective strategy. Recent technological advances came to significantly help as second-line investigation tools, especially the cardiac magnetic resonance, which allows for a more detailed ventricular evaluation, cardiac tissue characterization, and eliminates the poor acoustic window problem. This article aims to review all aspects related to sudden cardiac death in athletes, beginning with definitions and epidemiology, passing through etiology and clinical characteristics, then finishing with a discussion about the best ambulatory investigational approach.

A Recurrent Exertional Syncope and Sudden Cardiac Arrest in a Young Athlete with Known Pathogenic p.Arg420Gln Variant in the RYR2 Gene

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is one of causes of sudden cardiac death in the young, especially in athletes. Diagnosis of CPVT may be difficult since all cardiological examinations performed at rest are usually normal, and exercise stress test-induced ventricular tachycardia is not commonly present. The identification of a pathogenic mutation in RYR2 or CASQ2 is diagnostic in CPVT. We report on a 20-year-old athlete who survived two sudden cardiac arrests during swimming. Moreover, he suffered repeated syncopal spells on exercise. The diagnosis was made only following genetic testing using a multi-gene panel, and the p.Arg420Gln RYR2 variant was identified. We present diagnostic and therapeutic issues in this young athlete with CPVT.

The complexity of clinically-normal sinus-rhythm ECGs is decreased in equine athletes with a diagnosis of paroxysmal atrial fibrillation

Equine athletes have a pattern of exercise which is analogous to human athletes and the cardiovascular risks in both species are similar. Both species have a propensity for atrial fibrillation (AF), which is challenging to detect by ECG analysis when in paroxysmal form. We hypothesised that the proarrhythmic background present between fibrillation episodes in paroxysmal AF (PAF) might be detectable by complexity analysis of apparently normal sinus-rhythm ECGs. In this retrospective study ECG recordings were obtained during routine clinical work from 82 healthy horses and from 10 horses with a diagnosis of PAF. Artefact-free 60-second strips of normal sinus-rhythm ECGs were converted to binary strings using threshold crossing, beat detection and a novel feature detection parsing algorithm. Complexity of the resulting binary strings was calculated using Lempel-Ziv (‘76 & ‘78) and Titchener complexity estimators. Dependence of Lempel-Ziv ‘76 and Titchener T-complexity on the heart rate in ECG strips obtained at low heart rates (25–60 bpm) and processed by the feature detection method was found to be significantly different in control animals and those diagnosed with PAF. This allows identification of horses with PAF from sinus-rhythm ECGs with high accuracy.

Special Article - Exercise-induced right ventricular injury or arrhythmogenic cardiomyopathy (ACM): The bright side and the dark side of the moon

There is still debate on the range of normal physiologic changes of the right ventricle or ventricular (RV) function in athletes. Genetic links to arrhythmogenic cardiomyopathy (ACM) are well-established. There is no current consensus on the importance of extensive exercise and exercise-induced injury to the RV. During the intensive exercise of endurance sports, the cardiac structures adapt to athletic load over time. Some athletes develop RV cardiomyopathy possibly caused by genetic predisposition, whilst others develop arrhythmias from the RV. Endurance sports lead to increased volume and pressure load in both ventricles and increased myocardial mass. The extent of volume increase and changes in myocardial structure contribute to impairment of RV function and pose a challenge in cardiovascular sports medicine. Genetic predisposition to ACM may play an important role in the risk of sudden cardiac death of athletes. In this review, we discuss and evaluate existing results and opinions. Intensive training in competitive dynamic/power and endurance sports leads to specific RV adaptation, but physiological adaptation without genetic predisposition does not necessarily lead to severe complications in endurance sports. Discriminating between physiological adaptation and pathological form of ACM or RV impairment provoked by reinforced exercise presents a challenge to clinical sports cardiologists.