Diagnostic Yield of Genetic Testing in Young Athletes With T-Wave Inversion

Prevalence and prognosis of structural heart disease among athletes with negative T waves and normal transthoracic echocardiography

INTRODUCTION

The aim of the present study was to evaluate the prevalence and prognosis of structural heart disease (SHD) among competitive athletes with negative T waves without pathological findings at transthoracic echocardiogram.

METHODS

From a prospective register of 450 athletes consecutively evaluated during a second-level cardiological examination, we retrospectively identified all subjects with the following inclusion criteria: (1) not previously known cardiovascular disease; (2) negative T waves in leads other than V1-V2; (3) normal transthoracic echocardiogram. Patients underwent cardiac MRI and CT. The primary endpoint was the diagnosis of definite SHD after multimodality imaging evaluation. A follow-up was collected for a combined end-point of sudden death, resuscitated sudden cardiac death and hospitalization for any cardiovascular causes.

RESULTS

A total of 55 competitive athletes were finally enrolled (50 males, 90%) with a mean age of 27.5 ± 14.1 years. Among the population enrolled 16 (29.1%) athletes had a final diagnosis of SHD. At multivariate analysis, only deep negative T waves remained statistically significant [OR (95% CI) 7.81 (1.24-49.08), p = 0.0285]. Contemporary identification of deep negative T waves and complex arrhythmias in the same patients appeared to have an incremental diagnostic value. No events were collected at 49.3 ± 12.3 months of follow-up.

CONCLUSIONS

In a cohort of athletes with negative T waves at ECG, cardiac MRI (and selected use of cardiac CT) enabled the identification of 16 (29.1%) subjects with SHD despite normal transthoracic echocardiography. Deep negative T waves and complex ventricular arrhythmias were the only clinical characteristic associated with SHD diagnosis.

Unlocking the potential of artificial intelligence in sports cardiology: does it have a role in evaluating athlete's heart?

The integration of artificial intelligence (AI) technologies is evolving in different fields of cardiology and in particular in sports cardiology. Artificial intelligence offers significant opportunities to enhance risk assessment, diagnosis, treatment planning, and monitoring of athletes. This article explores the application of AI in various aspects of sports cardiology, including imaging techniques, genetic testing, and wearable devices. The use of machine learning and deep neural networks enables improved analysis and interpretation of complex datasets. However, ethical and legal dilemmas must be addressed, including informed consent, algorithmic fairness, data privacy, and intellectual property issues. The integration of AI technologies should complement the expertise of physicians, allowing for a balanced approach that optimizes patient care and outcomes. Ongoing research and collaborations are vital to harness the full potential of AI in sports cardiology and advance our management of cardiovascular health in athletes.

Nomogram for predicting cardiac death and heart transplantation in arrhythmogenic right ventricular cardiomyopathy

AIMS

In this study, we aimed to develop and validate a competing risk nomogram for predicting cardiac death and heart transplantation (HT) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).

METHODS

We retrospectively enrolled 149 consecutive patients with ARVC diagnosed at our institution between 2008 and 2022. Cox proportional hazards model was primarily used to identify variables associated with cardiac death and HT. On the basis of these indicators, a competing risk nomogram was developed to predict the 1, 3, and 5 year probabilities of cardiac death and HT. The area under the receiver operating characteristic curve (AUC), Harrell's C-index, and calibration curves were used to evaluate and internally validate the performance of the model. Decision curve analysis was performed to assess the clinical utility of the nomogram.

RESULT

Of the 149 patients with ARVC, the mean age was 38.77 ± 15.94 years, and most of the patients were men (67.11%, 100/149). Fourteen patients experienced cardiac death and nine underwent HT, during a median follow-up period of 5.8 years (interquartile range, 0.62-5.56 years). Multivariable COX analysis revealed that extent of TWI in the anterior and inferior leads (P = 0.0057), right atrial diameter on transthoracic echocardiography (P = 0.0498), RVEF (P = 0.1036), and LVEF (P < 0.001) all showed statistical significance. The 1-, 3-, and 5-year cumulative incidence of cardiac death and HT were 3.35%, 8.05%, and 11.4%, respectively. The area under the receiver operating characteristic curve of the nomogram for predicting cardiac death and HT at 1, 3, and 5 years after diagnosis of ARVC were 0.860, 0.935, and 0.956. The value of Harrell's C-index is 0.9273 (95% confidence interval 0.8954-0.9590; P < 0.001), indicating that the model had good discriminative ability in internal validation. Decision curve analysis revealed that our model was clinically useful within the entire range of potential treatment thresholds in most cases. The cumulative incidence of the primary outcomes was significantly different between the three risk groups according to nomogram-derived scores (P < 0.001).

CONCLUSIONS

On the basis of a retrospective review of patients with ARVC at a single centre, we developed a novel nomogram for predicting the risk of cardiac death and HT after ARVC diagnosis. This competing risk nomogram based on four readily available clinical parameters (right atrial diameter, right and left ventricular ejection fraction, and T-wave inversion) is a potentially useful tool for individualized prognostic assessment in patients with ARVC.

BEAT-IT: A de-novo cardiac screening programme in Maltese adolescents

AIMS

Sudden cardiac death (SCD) in young individuals is often unexpected, provoking substantial emotional stress for family and friends of the deceased. Cardiac screening may identify individuals who harbour disorders linked to SCD. The feasibility and diagnostic yield of a nationwide cardiac screening programme in adolescents has never been explored.

METHODS

All individuals eligible for cardiac screening (students aged 15 years) were systematically invited to enrol. Students were provided with a health questionnaire. ECGs were acquired at school. A physician led consultation was carried out on site. Participants with an abnormal screen were then referred for secondary evaluation to the nation's tertiary centre. Feasibility criteria included a) participation rate >60%, b) adherence to secondary evaluation >80%, and c) cost per individual screened equating to <€100. The diagnostic yield was also evaluated.

RESULTS

At the end of enrolment, 2708 students gave consent (mean 15 years, 50.4% male), equating to 67.9% of the eligible cohort. Overall, 109 participants (4.0%) were referred for further evaluation. An abnormal electrocardiogram (ECG) was the most common reason for referral (3.7%). Fifteen individuals (0.6%) were diagnosed with a cardiac condition. Nine (0.3%) had a condition linked to SCD (n = 1 Long-QT syndrome, n = 1 Hypertrophic Cardiomyopathy, n = 5 Wolff-Parkinson White, n = 2 coronary anomalies). The yield was similar in athletes and non-athletes (p = 0.324). The cost per cardiac individual screened equated to €51.15.

CONCLUSION

A nationwide systematic cardiac screening programme for adolescent athletes and non-athletes is feasible and cost-efficient, provided that responsible centres have the appropriate infrastructure.

Molecular genetic testing in athletes: Why and when a position statement from the Italian society of sports cardiology

Molecular genetic testing is an increasingly available test to support the clinical diagnosis of inherited cardiovascular diseases through identification of pathogenic gene variants and to make a preclinical genetic diagnosis among proband's family members (so-called "cascade family screening"). In athletes, the added value of molecular genetic testing is to assist in discriminating between physiological adaptive changes of the athlete's heart and inherited cardiovascular diseases, in the presence of overlapping phenotypic features such as ECG changes, imaging abnormalities or arrhythmias ("grey zone"). Additional benefits of molecular genetic testing in the athlete include the potential impact on the disease risk stratification and the implications for eligibility to competitive sports. This position statement of the Italian Society of Sports Cardiology aims to guide general sports medical physicians and sports cardiologists on clinical decision as why and when to perform a molecular genetic testing in the athlete, highlighting strengths and weaknesses for each inherited cardiovascular disease at-risk of sudden cardiac death during sport. The importance of early (preclinical) diagnosis to prevent the negative effects of exercise on phenotypic expression, disease progression and worsening of the arrhythmogenic substrate is also addressed.

Utility of Exercise Stress Testing in Pediatric Patients with T-Wave Inversions

T-wave inversions (TWI) in inferolateral electrocardiogram (ECG) leads (II, III, aVF, V5-V6) are often suggestive of cardiac pathology in adult patients. They are a common reason of additional testing in pediatric patients. The goal of the study is to determine correlation of exercise stress test T-wave response with diagnosis of cardiac pathology. This is a retrospective review of pediatric patients < 21 years with the finding of baseline TWI in inferior (II, III, avF) and/or lateral (V5-V6) leads on 12-lead ECG. All patients underwent treadmill exercise stress test (EST) and an echocardiogram within 1 year of each other. Demographics, baseline ECG findings, echocardiogram results, and EST data were recorded. T-wave reversion was considered complete if T waves demonstrated normalization during exercise, partial if there was minimal improvement, and no response if there was no change or worsening of inversions. In our cohort of 72 patients with a mean age 14.6 (± 2.9) years and 61% males, 59 (82%) had a structurally normal heart. Thirteen patients had evidence of structural or functional heart disease. Of the 59 patients, 83% had either complete or partial T-wave response. Among the 13 patients with heart disease, two patients had genetic testing consistent with risk for hypertrophic cardiomyopathy and had complete and partial response on EST. Exercise stress testing for TWI in pediatric patients has low sensitivity and specificity for the diagnosis of cardiac disease and routine use in this patient population may not be indicated.

Overlap phenotypes of the left ventricular noncompaction and hypertrophic cardiomyopathy with complex arrhythmias and heart failure induced by the novel truncated DSC2 mutation

Background

The left ventricular noncompaction cardiomyopathy (LVNC) is a rare subtype of cardiomyopathy associated with a high risk of heart failure (HF), thromboembolism, arrhythmia, and sudden cardiac death.

Methods

The proband with overlap phenotypes of LVNC and hypertrophic cardiomyopathy (HCM) complicates atrial fibrillation (AF), ventricular tachycardia (VT), and HF due to the diffuse myocardial lesion, which were diagnosed by electrocardiogram, echocardiogram and cardiac magnetic resonance imaging. Peripheral blood was collected from the proband and his relatives. DNA was extracted from the peripheral blood of proband for high-throughput target capture sequencing. The Sanger sequence verified the variants. The protein was extracted from the skin of the proband and healthy volunteer. The expression difference of desmocollin2 was detected by Western blot.

Results

The novel heterozygous truncated mutation (p.K47Rfs*2) of the DSC2 gene encoding an important component of desmosomes was detected by targeted capture sequencing. The western blots showed that the expressing level of functional desmocollin2 protein (~ 94kd) was lower in the proband than that in the healthy volunteer, indicating that DSC2 p.K47Rfs*2 obviously reduced the functional desmocollin2 protein expression in the proband.

Conclusion

The heterozygous DSC2 p.K47Rfs*2 remarkably and abnormally reduced the functional desmocollin2 expression, which may potentially induce the overlap phenotypes of LVNC and HCM, complicating AF, VT, and HF.

Pathogenic variants in plakophilin-2 gene (PKP2) are associated with better survival in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is mainly caused by mutations in genes encoding desmosomal proteins. Variants in plakophilin-2 gene (PKP2) are the most common cause of the disease, associated with conventional ARVC phenotype. The study aims to evaluate the prevalence of PKP2 variants and examine genotype-phenotype correlation in Polish ARVC cohort. All 56 ARVC patients fulfilling the current criteria were screened for genetic variants in PKP2 using denaturing high-performance liquid chromatography or next-generation sequencing. The clinical evaluation involved medical history, electrocardiogram, echocardiography, and follow-up. Ten variants (5 frameshift, 2 nonsense, 2 splicing, and 1 missense) in PKP2 were found in 28 (50%) cases. All truncating variants are classified as pathogenic/likely pathogenic, while the missense variant is classified as variant of uncertain significance. Patients carrying a PKP2 mutation were younger at diagnosis (p = 0.003), more often had negative T waves in V1-V3 (p = 0.01), had higher left ventricular ejection fraction (p = 0.04), and were less likely to present symptoms of heart failure (p = 0.01) and left ventricular damage progression (p = 0.04). Combined endpoint of death or heart transplant was more frequent in subgroup without PKP2 mutation (p = 0.03). Pathogenic variants in PKP2 are responsible for 50% of ARVC cases in the Polish population and are associated with a better prognosis. ARVC patients with PKP2 mutation are less likely to present left ventricular involvement and heart failure symptoms. Combined endpoint of death or heart transplant was less frequent in this group.

Association of T-wave abnormalities with major cardiovascular events in diabetes: the ACCORD trial

AIMS/HYPOTHESIS

T-wave abnormalities (TWA) are often found on ECG and signify abnormal ventricular repolarisation. While TWA have been shown to be associated with subclinical atherosclerosis, the relationship between TWA and hard cardiovascular endpoints is less clear and may differ in the presence of diabetes, so we sought to explore these associations in participants from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

METHODS

TWA were operationally defined as the presence of any Minnesota Codes 5-1 through 5-4 in any lead distribution. Multivariable Cox proportional hazards models were constructed to examine relationships between TWA and clinical cardiovascular events. Secondary analyses explored the risks conferred by major vs minor TWA, differential effects of TWA by anatomic localisation (anterolateral, inferior or anterior lead distributions), and differing associations in those with or without prevalent CVD.

RESULTS

Among 8176 eligible participants (mean 62.1 ± 6.3 SD years, 61.4% male), there were 3759 cardiovascular events, including 1430 deaths (473 of a cardiovascular aetiology), 474 heart failure events, 1452 major CHD events and 403 strokes. Participants with TWA had increased risks of all-cause mortality (HR 1.45 [95% CI 1.30, 1.62], p < 0.0001), cardiovascular mortality (HR 1.93 [1.59, 2.34], p = 0.0001), congestive heart failure (HR 2.04 [1.69, 2.48], p < 0.0001) and major CHD (HR 1.40 [1.26, 1.57], p < 0.0001), but no increased risk of stroke (HR 0.99 [0.80, 1.23], p = 0.95). Major TWA conferred a higher risk than minor TWA. When TWA were added to the UK Prospective Diabetes Study risk engine, there was improved discrimination for incident CHD events, but only for those with prevalent CVD (area under the receiver operating characteristic curve 0.5744 and 0.6030 with p = 0.0067). Adding TWA to the risk engine yielded improvements in reclassification that were of greater magnitude in those with prevalent CVD (net reclassification improvement [NRI] 0.24 [95% CI 0.16, 0.32] in those with prevalent CVD, NRI 0.14 [95% CI 0.07, 0.22] in those without prevalent CVD).

CONCLUSIONS/INTERPRETATION

The presence and magnitude of TWA are associated with increased risk of clinical cardiovascular events and mortality in individuals with diabetes and may have value in refining risk, particularly in those with prevalent CVD. Graphical abstract.

Papillary Muscles Abnormalities in Athletes With Otherwise Unexplained T-Wave Inversion in the ECG Lateral Leads

Background

Papillary muscles (PMs) abnormalities may be associated with ECG repolarization abnormalities. We aimed to evaluate the relation between lateral T‐wave inversion (TWI) and PMs characteristics in a cohort of athletes with no clinically demonstrable cardiac disease.

Methods and Results

We included 53 athletes (median age, 20 years; 87% men) with lateral TWI and no evidence of heart disease on clinical and cardiac magnetic resonance evaluation. A group of healthy athletes with normal ECG served as controls. We evaluated the PMs dimensions, such as diameters, area, volume, mass, and ratio between PMs and left ventricular mass, and the prevalence of PMs apical displacement. Compared with controls, athletes with TWI showed PMs hypertrophy with significantly increased PMs diameters, area, volume, and mass. The ratio between PMs and left ventricular mass was 4.4% in athletes with TWI and 3.0% in controls (P<0.001). A PMs/left ventricular mass ratio >3.5% showed 85% sensitivity and 76% specificity for differentiating between athletes with TWI and controls. Apical displacement of PMs was found in 25 (47%) athletes with TWI versus 9 (17%) controls (P=0.001). At multivariable analysis, PMs/left ventricular mass ratio and apical displacement remained independent predictors of TWI. Clinical outcome of the athletes with TWI and PMs abnormalities was uneventful despite continuation of their sports activity.

Conclusions

PMs hypertrophy and apical displacement may underlie otherwise unexplained lateral TWI in the athlete. Lateral TWI associated with PMs abnormalities appears as a distinct anatomo‐clinical condition characterized by a favorable outcome.

High-Resolution Cryo-EM Structure of the Cardiac Actomyosin Complex

Heart contraction depends on a complicated array of interactions between sarcomeric proteins required to convert chemical energy into mechanical force. Cyclic interactions between actin and myosin molecules, controlled by troponin and tropomyosin, generate the sliding force between the actin-based thin and myosin-based thick filaments. Alterations in this sophisticated system due to missense mutations can lead to cardiovascular diseases. Numerous structural studies proposed pathological mechanisms of missense mutations at the myosin-myosin, actin-tropomyosin, and tropomyosin-troponin interfaces. However, despite the central role of actomyosin interactions a detailed structural description of the cardiac actomyosin interface remained unknown. Here, we report a cryo-EM structure of a cardiac actomyosin complex at 3.8 Å resolution. The structure reveals the molecular basis of cardiac diseases caused by missense mutations in myosin and actin proteins.

The Hidden Fragility in the Heart of the Athletes: A Review of Genetic Biomarkers

Sudden cardiac death (SCD) is a devastating event which can also affect people in apparent good health, such as young athletes. It is known that intense and continuous exercise along with a genetic background that predisposes a person to the risk of fatal arrhythmias is a trigger for SCD. Therefore, knowledge of the athlete’s genetic conditions underlying the onset of SCD must be extended, in order to develop new effective prevention and/or therapeutic strategies. Arrhythmic features occur across a broad spectrum of cardiac diseases, sometimes presenting with overlapping phenotypes. The genetic basis of arrhythmogenic disorders has been greatly highlighted in the last 30 years, and has shown marked heterogeneity. The advent of next-generation sequencing has constantly updated our understanding of the genetic basis of arrhythmogenic diseases and is laying the foundation for precision medicine. With the exception of a few clinical cases involving a single athlete showing a highly suspected phenotype for the presence of a heart disease, there are few studies to date that analysed the applicability of genetic testing on cohorts of athletes. This evidence shows that genetic testing can contribute to the diagnosis of up to 13% of athletes; however, the presence of clinical markers is essential. This review aims to provide a reference collection on current knowledge of the genetic basis of sudden cardiac death in athletes and to review updated evidence on the effectiveness of genetic testing in early identification of athletes at risk for SCD.

Impact of cardiac magnetic resonance on the diagnosis of hypertrophic cardiomyopathy - a 10-year experience with over 1000 patients

Objectives

To assess the value of cardiac MRI in comparison to echocardiography in consecutive patients with previously diagnosed and new suspected hypertrophic cardiomyopathy (HCM).

Methods

All MRI studies of patients with HCM or suspected disease performed at our centre within a 10-year time period were evaluated. Initial diagnoses (echocardiography-based) and final (MRI-based) diagnoses were compared in subgroups, and the discrepancies were recorded.

Results

A total of 1006 subjects with HCM or suspected HCM were identified (61% males, 39% females; median age, 49.1 years; interquartile range, 34.9–60.4). In 12 (2.2%) out of 550 patients with known HCM, MRI indicated a diagnosis other than HCM, including but not limited to the subaortic membrane (n = 1, 8.3%) or mild left ventricular hypertrophy (n = 5, 41.7%). Among all patients with suspected HCM (n = 456), MRI diagnosis was different from HCM in 5.3% (n = 24) of patients. In an additional 20.4% of patients (n = 93), no significant hypertrophy was present. In total, among patients with suspected HCM, MRI led to clear HCM diagnosis in 204 (44.7%) patients. Among patients with a history of uncontrolled hypertension suspected of having HCM, MRI aided in identifying cardiomyopathy in 47.9% of patients. This subgroup contained the largest proportion of patients with an ambiguous diagnosis, namely, 29.6% compared with 13.8% in the remaining groups of patients with suspected HCM (p = 0.0001).

Conclusions

In a small but important group of patients with ultrasound-based HCM, cardiac MRI can diagnose previously unknown conditions and/or refute suspected cardiomyopathy. The diagnostic yield of MRI when compared to echocardiography in patients suspected of having HCM is 44.7%.

Key Points

• Out of 550 patients previously diagnosed with echocardiography but without magnetic resonance imaging (MRI) as having hypertrophic cardiomyopathy (HCM), we diagnosed a different disease in 12 (2.2%) patients using MRI.

• Among patients with suspected HCM based on echocardiography, MRI led to clear HCM diagnosis in 44.7% of patients.

• In patients with a history of uncontrolled hypertension suspected, based on an echocardiogram, of having HCM, MRI aided in identifying cardiomyopathy in 47.9% of patients. This subgroup contained the largest proportion of patients with an ambiguous diagnosis.

The Impact of Ethnicity on Cardiac Adaptation

Regular intensive exercise is associated with a plethora of electrical, structural and functional adaptations within the heart to promote a prolonged and sustained increase in cardiac output. Bradycardia, increased cardiac dimensions, enhanced ventricular filling, augmentation of stroke volume and high peak oxygen consumption are recognised features of the athlete's heart. The type and magnitude of these adaptations to physical exercise are governed by age, sex, ethnicity, sporting discipline and intensity of sport. Some athletes, particularly those of African or Afro-Caribbean (black) origin reveal changes that overlap with diseases implicated in sudden cardiac death. In such instances, erroneous interpretation has potentially serious consequences ranging from unfair disqualification to false reassurance. This article focuses on ethnic variation in the physiological cardiac adaption to exercise.

Yield and clinical significance of genetic screening in elite and amateur athletes

AIMS

The purpose of this study was to assess the value of genetic testing in addition to a comprehensive clinical evaluation, as part of the diagnostic work-up of elite and/or amateur Italian athletes referred for suspicion of inherited cardiac disease, following a pre-participation screening programme.

METHODS

Between January 2009-December 2018, of 5892 consecutive participants, 61 athletes were investigated: 30 elite and 31 amateur athletes. Elite and amateur athletes were selected, on the basis of clinical suspicion for inherited cardiac disease, from two experienced centres for a comprehensive cardiovascular evaluation. Furthermore, the elite and amateur athletes were investigated for variants at DNA level up to 138 genes suspected to bear predisposition for possible cardiac arrest or even sudden cardiac death.

RESULTS

Of these 61 selected subjects, six (10%) had diagnosis made possible by a deeper clinical evaluation, while genetic testing allowed a definite diagnosis in eight (13%). The presence of >3 clinical markers (i.e. family history, electrocardiogram and/or echocardiographic abnormalities, exercise-induced ventricular arrhythmias) was associated with a higher probability of positive genetic diagnosis (75%), compared with the presence of two or one clinical markers (14.2%, 8.1%, respectively, p-value = 0.004).

CONCLUSION

A combined clinical and genetic evaluation, based on the subtle evidence of clinical markers for inherited disease, was able to identify an inherited cardiac disease in about one-quarter of the examined athletes.

Inferolateral T wave inversion in athletes: phenotype-genotype correlation

AIMS

Significant T wave inversion in young asymptomatic athletes is rare but poses a significant clinical challenge. Pre-participation sports screening programs identify such subjects. Clinical concern that such ECG changes represent an occult cardiomyopathy or forme fruste hypertrophic cardiomyopathy leads to diagnostic and therapeutic dilemma. We sought to genotype a cohort of such subjects with a normal cardiac phenotype identified in our unit over a 3-year period.

METHODS

Ten athletes were referred from external screening. All exhibited deep T wave inversion inferolaterally. All had negative family history for sudden death and had a normal phenotype. A panel of 133 cardiac genes were screened.

RESULTS

Ten male subjects with mean age of 39 years were screened. Seven had no evidence of mutations. Three subjects demonstrated variants of uncertain significance in 5 different genes: alpha-2-actinin (ACTN2), myopalladin (MYPN), the calcium channel genes CACNA1C and TRPM4 and potassium channel gene KCNQ1. The variants found have not been described in cardiomyopathies or channelopathies. At 3-year follow-up, one patient had undergone detraining, and his ECG showed complete resolution of all T wave changes. He did not have any demonstrated variants.

CONCLUSIONS

The absence of mutations in target genes and heterogeneous sequence variations identified in this study suggest that inferolateral T wave inversion in athletes without a phenotype may potentially represent a benign repolarization syndrome related to athletic adaptation. This was the first study to assess a phenotype-genotype correlation in this population. Further genetic studies need to be undertaken in this area.

Association Analysis of Single-Cell RNA Sequencing and Proteomics Reveals a Vital Role of Ca2+ Signaling in the Determination of Skeletal Muscle Development Potential

This study is aimed at exploring the mechanism underlying the homeostasis between myogenesis and adipogenesis in skeletal muscle using a special porcine model with a distinct phenotype on muscle growth rate and intramuscular fat deposition. Differentiation potential of muscle-derived Myo-lineage cells of lean-type pigs was significantly enhanced relative to obese-type pigs, while that of their Adi-lineage cells was similar. Single-cell RNA sequencing revealed that lean-type pigs reserved a higher proportion of Myo-lineage cells in skeletal muscle relative to obese-type pigs. Besides, Myo-lineage cells of the lean-type pig settled closer to the original stage of muscle-derived progenitor cells. Proteomics analysis found that differentially expressed proteins between two sources of Myo-lineage cells are mainly involved in muscle development, cell proliferation and differentiation, ion homeostasis, apoptosis, and the MAPK signaling pathway. The regulation of intracellular ion homeostasis, Ca²⁺ in particular, significantly differed between two sources of Myo-lineage cells. Ca²⁺ concentration in both cytoplasm and endoplasmic reticulum was lower in Myo-lineage cells of lean-type pigs relative to obese-type pigs. In conclusion, a higher proportion and stronger differentiation capacity of Myo-lineage cells are the main causes for the higher capability of myogenic differentiation and lower intramuscular fat deposition. Relative low concentration of cellular Ca²⁺ is advantageous for Myo-lineage cells to keep a potent differentiation potential.

Interpretation of T-wave inversion in physiological and pathological conditions: Current state and future perspectives

The presence of T‐wave inversion (TWI) at 12‐lead electrocardiogram (ECG) in competitive athletes is one of the major diagnostic challenges for sports physicians and consulting cardiologists. Indeed, while the presence of TWI may be associated with some benign conditions and it may be occasionally seen in healthy athletes presenting signs of cardiac remodeling, it may also represent an early sign of an underlying, concealed structural heart disease or life‐threatening arrhythmogenic cardiomyopathies, which may be responsible for exercise‐related sudden cardiac death (SCD). The interpretation of TWI in athletes is complex and the inherent implications for the clinical practice represent a conundrum for physicians. Accordingly, the detection of TWI should be viewed as a potential red flag on the ECG of young and apparently healthy athletes and warrants further investigations because it may represent the initial expression of cardiomyopathies that may not be evident until many years later and that may ultimately be associated with adverse outcomes. The aim of this review is, therefore, to report an update of the literature on TWI in athletes, with a specific focus on the interpretation and management.

Utility of genetic testing in athletes

Athletes are some of the fittest members of our society, yet paradoxically carry an increased risk of sudden cardiac death (SCD). The athlete's underlying risk of SCD in sports may be increased due to a number of underlying structural, arrhythmic and inherited cardiac conditions (ICCs). There are also physiological adaptations, which occur in the cardiovascular system in athletes as a result of high‐level athletic activity and may be misinterpreted as pathology. Differentiation of “athlete's heart” from heart disease may be challenging due to the effects of exercise on the electrical and structural cardiac remodeling. Features such as prolongation of the QT interval, left ventricular hypertrophy and cavity dilatation, create significant overlap between physiology and inherited channelopathies and cardiomyopathies. Most inherited cardiac conditions have an underlying genetic basis to disease and genetic testing in an athlete can have diagnostic, prognostic and therapeutic implications, including guiding exercise recommendations. Therefore, genetic testing can be a useful diagnostic tool when used carefully and appropriately by a trained cardio‐genetics expert.

[ECG in sportsmen: Distinguishing the normal from the pathological]

An ECG is recommended by the French Society of Cardiology in the screening of a competitive athlete. An intense and prolonged physical activity (>4 hours of intense sport/week) can lead to a physiological electric remodeling. In addition to physical activity (type, intensity, duration), the ECG should be interpreted according to the athlete's ethnicity and age. It is necessary to know the physiological modifications related to sport practice to avoid either false reassurances or the realization of unjustified additional examinations because of a wrong interpretation. The latest athlete ECG classification published in 2017 can be used to identify in which athlete additional tests are recommended (figure 1).

Canadian Cardiovascular Society Cardiovascular Screening of Competitive Athletes: The Utility of the Screening Electrocardiogram to Predict Sudden Cardiac Death

Prevention of sudden cardiac arrest/death (SCA/D) among athletes is a universal goal, although the optimal strategy for its achievement is controversial, with the inclusion of the 12-lead electrocardiogram (ECG) at the center of the debate. The ECG exhibits superior sensitivity over history and physical examination to detect conditions associated with SCA/D. However, the identification of disease does not necessarily lead to a significant reduction in SCA/D. The "Canadian Cardiovascular Society/Canadian Heart Rhythm Society Joint Position Statement on the Cardiovascular Screening of Competitive Athletes" recommended against the routine performance of an ECG for the initial cardiovascular screening of competitive athletes. The incidence of SCA/D among athletes (<35 years of age), the risk of SCA/D during sport participation among individuals with abnormalities found on screening ECG, the efficacy of the ECG to identify conditions associated with SCA/D, and the positive predictive value of an abnormal ECG to predict SCA/D are critically examined. This review presents the evidence informing the panel's recommendation.

Prevalence and significance of T-wave inversion in Arab and Black paediatric athletes: Should anterior T-wave inversion interpretation be governed by biological or chronological age?

BACKGROUND

International electrocardiographic (ECG) recommendations regard anterior T-wave inversion (ATWI) in athletes under 16 years to be normal.

DESIGN

The aim of this study was to identify the prevalence, distribution and determinants of TWI by ethnicity, chronological and biological age within paediatric athletes. A second aim was to establish the diagnostic accuracy of international ECG recommendations against refinement within athletes who present with ECG variants isolated to ATWI (V₁-V₄) using receiver operator curve analysis. Clinical context was calculated using Bayesian analysis.

METHODS

Four hundred and eighteen Arab and 314 black male athletes (11-18 years) were evaluated by ECG, echocardiogram and biological age (by radiological X-ray) assessment.

RESULTS

A total of 116 (15.8%) athletes presented with ATWI (V₁-V₄), of which 96 (82.8%) were observed in the absence of other ECG findings considered to be abnormal as per international recommendations for ECG interpretation in athletes; 91 (12.4%) athletes presented with ATWI confined to V₁-V₃, with prevalence predicted by black ethnicity (odds ratio (OR) 2.2, 95% confidence interval (CI) 1.3-3.5) and biological age under 16 years (OR 2.0, 95% CI 1.2-3.3). Of the 96 with ATWI (V₁-V₄) observed in the absence of other ECG findings considered to be abnormal, as per international recommendations for ECG interpretation in athletes, diagnostic accuracy was 'fail' (OR 0.47, 95% CI 0.00-1.00) for international recommendations and 'excellent' (OR 0.97, 95% CI 0.92-1.00) when governed by biological age under 16 years, providing a positive and negative likelihood ratio of 15.8 (95% CI 1.8-28.1) and 0.0 (95% CI 0.0-0.8), respectively.

CONCLUSION

Interpretation of ECG variants isolated with ATWI (V₁-V₄) using international recommendations (chronological age <16 years) warrants caution, but governance by biological age yielded an 'excellent' diagnostic accuracy. In the clinical context, the 'chance' of detecting cardiac pathology within a paediatric male athlete presenting with ATWI in the absence of other ECG findings considered to be abnormal, as per international recommendations for ECG interpretation in athletes (positive likelihood ratio 15.8), was 14.4%, whereas a negative ECG (negative likelihood ratio 0.0) was 0%.

Left Ventricular Hypertrophy in Athletes: Differentiating Physiology From Pathology

PURPOSE OF REVIEW

The changes that occur in athlete's heart are influenced by a number of factors including age, gender, ethnicity and the type of cardiovascular training. It is therefore important that the clinician is able to integrate all of these factors when assessing athletes to be able to guide investigations appropriately and to distinguish pathology from physiology. This review discusses the potential diagnostic conundrums when trying to differentiate physiological left ventricular hypertrophy from pathological hypertrophic cardiomyopathy in athletes. The mechanism of physiological and pathological hypertrophy is discussed together with history, clinical and investigational findings that can help to identify pathology.

RECENT FINDINGS

Athletes with hypertrophic cardiomyopathy are more likely to have non-concentric left ventricular hypertrophy (LVH), an elevated relative wall thickness, lateral ECG changes and a smaller LV cavity than athletes with physiological LVH. Certain diastolic echocardiographic parameters when used as part of an algorithm (e'; E/E'; E/A) can help to distinguish physiology from pathology, and there is evidence that assessment of global longitudinal strain during exercise echocardiography may be of use in the future. Cardiac MRI is an important imaging modality that can have an additive effect over echocardiography in the diagnosis of cardiomyopathy. Late gadolinium enhancement is a recognised advantage for cardiac magnetic resonance to allow detection of fibrosis in hypertrophic cardiomyopathy. T1 mapping and extracellular volume quantification may be a tool for the future to help distinguish athlete's heart from HCM. Cardiac adaptation to exercise and training in athletes, the athlete's heart causes electrophysiological and geometric changes that may mimic mild phenotypes of a pathological cardiomyopathy. This review article summarises a systematic approach to the assessment of left ventricular hypertrophy in athletes and describes pertinent clinical and investigation findings that can help to differentiate physiology from pathology.