Electrical and structural adaptations of the paediatric athlete’s heart: a systematic review with meta-analysis

Electrocardiographic characteristics of pediatric and adolescent football players

Electrocardiographic characteristics of children and adolescents present differences compared to adults. The aim of our work was to study electrocardiograms (ECGs) of football male players from childhood to late adolescence and examine if the ECG parameters are influenced by systematic exercise. One thousand fifty-four football players participated and formed four groups. Group A included 89 players aged 5-7 years, group B 353 players aged 8-11 years, group C consisted of 355 football players 12-15 yearsold and group D of 257 players with 16-18 years of age. All participants underwent preparticipation screening, including 12-lead surface ECG. Heart rate (HR), PR, RR, QRS, QT, QTc intervals, QT dispersion (QTdisp) and QRS axis were calculated. All ECGs were evaluated according to the current preparticipation cardiac screening guidelines, that refer to athletes aged 12-35 years and do not include pediatric players. Eleven percent of the participants presented an ECG finding. Group D obtained the lowest values of HR, QTc and the highest of PR, RR, QRS, QT intervals and QTdisp, whereas no differences in QRS axis were reported. Incomplete Right Bandle Branch Block (RBBB) was the most frequent ECG peculiarity, detected in 7.3% of the participants. Years of training were statistically significantly correlated to HR, PR, RR, QRS and QT intervals. In conclusion, guidelines for ECG interpretation of athletes in childhood, early and late adolescence are needed.

Adaptation of Left Ventricular Twist Mechanics in Exercise-Trained Children Is Only Evident after the Adolescent Growth Spurt

BACKGROUND

The extent of structural cardiac remodeling in response to endurance training is maturity dependent. In adults, this structural adaptation is often associated with the adaptation of left ventricular (LV) twist mechanics. For example, an increase in LV twist often follows an expansion in end-diastolic volume, whereas a reduction in twist may follow a thickening of the LV walls. While structural cardiac remodeling has been shown to be more prominent post-peak height velocity (PHV), it remains to be determined how this maturation-dependent structural remodeling influences LV twist. Therefore, we aimed to (1) compare LV twist mechanics between trained and untrained children pre- and post-PHV and (2) investigate how LV structural variables relate to LV twist mechanics pre- and post-PHV.

METHODS

Left ventricular function and morphology were assessed (echocardiography) in endurance-trained and untrained boys (n = 38 and n = 28, respectively) and girls (n = 39 and n = 34, respectively). Participants were categorized as either pre- or post-PHV using maturity offset to estimate somatic maturation.

RESULTS

Pre-PHV, there were no differences in LV twist or torsion between trained and untrained boys (twist: P = .630; torsion: P = .382) or girls (twist: P = .502; torsion: P = .316), and LV twist mechanics were not related with any LV structural variables (P > .05). Post-PHV, LV twist was lower in trained versus untrained boys (P = .004), with torsion lower in trained groups, irrespective of sex (boys: P < .001; girls: P = .017). Moreover, LV torsion was inversely related to LV mass (boys: r = -0.55, P = .001; girls: r = -0.46, P = .003) and end-diastolic volume (boys: r = -0.64, P < .001; girls: r = -0.36, P = .025) in both sexes.

CONCLUSIONS

A difference in LV twist mechanics between endurance-trained and untrained cohorts is only apparent post-PHV, where structural and functional remodeling were related.

Distinguishing left ventricular hypertrophy from hypertrophic cardiomyopathy in adolescents: a longitudinal observation study

AIMS

Echocardiographic characteristics to distinguish physiological left ventricular (LV) hypertrophy from pathology are warranted in early adolescent athletes. This study aimed to explore the phenotype, progression, and potential grey zone of LV hypertrophy during adolescence in athletes and hypertrophic cardiomyopathy (HCM) genotype-positive patients.

METHODS AND RESULTS

In this longitudinal observation study, we compared seventy-six 12-year-old athletes with 55 age-matched and sex-matched HCM genotype-positive patients. Echocardiographic parameters were evaluated by using paediatric reference values (Z-scores). Hypertrophic cardiomyopathy genotype-positive patients were included if they had no or mild LV hypertrophy [maximum wall thickness <13 mm, Z-score <6 for interventricular septum diameter (ZIVSd), or posterior wall thickness]. We collected clinical data, including data on cardiac events. The mean follow-up-time was 3.2 ± 0.8 years. At baseline, LV hypertrophy was found in 28% of athletes and 21% of HCM genotype-positive patients (P = 0.42). Septum thickness values were similar (ZIVSd 1.4 ± 0.9 vs. 1.0 ± 1.3, P = 0.08) and increased only in HCM genotype-positive patients {ZIVSd progression rate -0.17 [standard error (SE) 0.05], P = 0.002 vs. 0.30 [SE 0.10], P = 0.001}. Left ventricular volume Z-scores (ZLVEDV) were greater in athletes [ZLVEDV 1.0 ± 0.6 vs. -0.1 ± 0.8, P < 0.001; ZLVEDV progression rate -0.05 (SE 0.04), P = 0.21 vs. -0.06 (SE 0.04), P = 0.12]. Cardiac arrest occurred in two HCM genotype-positive patients (ages 13 and 14), with ZIVSd 8.2-11.5.

CONCLUSION

Left ventricular hypertrophy was found in a similar proportion in early adolescence but progressed only in HCM genotype-positive patients. A potential grey zone of LV hypertrophy ranged from a septum thickness Z-score of 2.0 to 3.3. Left ventricular volumes remained larger in athletes. Evaluating the progression of wall thickness and volume may help clinicians distinguish physiological LV hypertrophy from early HCM.

Right Ventricular Structure and Function in Adolescent Athletes: A 3D Echocardiographic Study

The aim of this study was to characterize the right ventricular (RV) contraction pattern and its associations with exercise capacity in a large cohort of adolescent athletes using resting three-dimensional echocardiography (3DE). We enrolled 215 adolescent athletes (16±1 years, 169 males, 12±6 hours of training/week) and compared them to 38 age and sex-matched healthy, sedentary adolescents. We measured the 3DE-derived biventricular ejection fractions (EF). We also determined the relative contributions of longitudinal EF (LEF/RVEF) and radial EF (REF/RVEF) to the RVEF. Same-day cardiopulmonary exercise testing was performed to calculate VO2/kg. Both LV and RVEFs were significantly lower (athletes vs. controls; LVEF: 57±4 vs 61±3, RVEF: 55±5 vs 60±5%, p<0.001). Interestingly, while the relative contribution of radial shortening to the global RV EF was also reduced (REF/RVEF: 0.40±0.10 vs 0.49±0.06, p<0.001), the contribution of the longitudinal contraction was significantly higher in athletes (LEF/RVEF: 0.45±0.08 vs 0.40±0.07, p<0.01). The supernormal longitudinal shortening correlated weakly with a higher VO2/kg (r=0.138, P=0.044). Similarly to the adult athlete's heart, the cardiac adaptation of adolescent athletes comprises higher biventricular volumes and lower resting functional measures with supernormal RV longitudinal shortening. Characteristic exercise-induced structural and functional cardiac changes are already present in adolescence.

The effect of long-term soccer training on left ventricular structure and function in elite male youth soccer players

AIMS

Cardiac adaptations in elite, male adolescent youth soccer players have been demonstrated in relation to training status. The time course of these adaptations and the delineation of the influence of volatile growth phases from the training effect on these adaptations remain unclear. Consequently, the aims of the study were to evaluate the impact of 3 years of elite-level soccer training on changes in left ventricular (LV) structure and function in a group of highly trained elite youth male soccer players (SP) as they transitioned through the pre-to-adolescent phase of their growth.

METHODS

Twenty-two male youth SP from the highest Level of English Premier League Academy U-12 teams were evaluated once a year for three soccer seasons as the players progressed from the U-12 to U-14 teams. Fifteen recreationally active control participants (CON) were also evaluated over the same 3-year period. Two-dimensional transthoracic echocardiography was used to quantify LV structure and function.

RESULTS

After adjusting for the influence of growth and maturation, training-induced increases in Years 2 and 3 were noted for: LV end diastolic volume (LVEDV; p = 0.02) and LV end systolic volume (LVESV; p = 0.02) in the SP compared to CON. Training-induced decrements were noted for LV ejection fraction (LVEF; p = 0.006) and TDI-S' (p < 0.001).

CONCLUSIONS

An increase in training volume (Years 2 and 3) were aligned with LV volumetric adaptations and decrements in systolic function in the SP that were independent from the influence of rapid somatic growth. Decrements in systolic function were suggestive of a functional reserve for exercise.

Aortic Diameters and Calcifications in Former World-Class Cyclists

PURPOSE

Concerns on whether athletes--particularly older ones--are at an increased risk of pathological aortic dilation exist, and the prevalence of aortic calcifications in these individuals is unknown. We aimed to compare the dimensions, distensibility, and prevalence of calcifications in the thoracic aorta between former male professional cyclists (cases) and sex/age-matched controls.

METHODS

We used a retrospective cohort design, where cases were former finishers of at least one Grand Tour (Tour de France, Giro d' Italia or Vuelta a España) and controls were untrained individuals with no previous sports history and free of cardiovascular risk. All participants underwent magnetic resonance and computer tomography assessments for the measurement of aortic dimensions and calcifications, respectively.

RESULTS

Cases showed larger ( P < 0.05) dimensions than controls for aortic annulus, sinus, and arch, as well as for ascending and descending aorta. However, none of the participants presented with pathological aortic dilation (all diameters <40 mm). A slightly higher prevalence of calcifications in the ascending aorta was observed in cases (13% vs 0% in controls, P = 0.020). Subanalyses confirmed that cases who were still competing (masters category, n = 8) had larger aortic diameters ( P < 0.05) and a greater presence of calcifications in the ascending/descending aorta (38% vs 0% for both segments, P = 0.032) than those who had become inactive ( n = 15). No between-group differences were found for aortic distensibility.

CONCLUSIONS

Former professional cyclists, particularly those who are still competing after retirement, show enlarged aortic diameters (albeit without exceeding upper limits of normality). Former professional cyclists also showed a slightly higher prevalence of calcifications in the ascending aorta than controls, although aortic distensibility was not compromised. The clinical relevance of these findings should be the subject of future studies.

Electrocardiographic findings in pediatric versus young-adolescent athletes: A comparative analysis using general international criteria

BACKGROUND

The inclusion of electrocardiogram (ECG) in medical examinations for sports practice serves as a valuable tool for identifying potential life-threatening conditions during physical exercise. However, its applicability in young individuals remains a subject of controversy, primarily due to relatively high rates of false positives and the associated costs of further investigations. Furthermore, the validation of International Criteria for athletes below 12 years of age in optimizing pre-participation screening for young athletes is yet to be established. In light of these considerations, this study aims to describe the prevalence of ECG findings in a sample of children and young-adolescent athletes aged 11-16 years, employing refined Seattle interpretation criteria. Additionally, we seek to compare these findings based on age group and sex.

METHODS

This was a retrospective and observational study of 3747 athletes 11-16 year-olds. Evaluation included interviewer-administered questionnaires for relevant history, physical examination and resting 12 - lead ECG for each participant. The primary outcome measure was abnormal ECG findings according to the International Recommendations for Electrocardiographic Interpretation in Athletes.

RESULTS

Among the evaluated population of pediatric and young adolescent athletes (77.5% boys; >99% Caucasian), the vast majority exhibited normal electrocardiogram (ECG) results, with adaptive findings related to sports participation being more frequent among young adolescents and males. The presence of significant ECG abnormalities in young-adolescent athletes was uncommon (2.05%; 1.92% children and 2.32% young-adolescent) and required additional examinations. 0.27% of the total population were diagnosed with a previously unknown cardiac pathology only through the ECG.

CONCLUSIONS

This study provides valuable insights into the prevalence of normal, borderline, and abnormal electrocardiogram (ECG) findings in a large population of pediatric and young-adolescent athletes. These findings serve as guidance in detecting potentially serious cardiac alterations within this specific group, considering variations based on age and sex. The study confirms that ECG screening is a useful tool for identifying cardiac abnormalities in pediatric and young-adolescent athletes, even though the prevalence of significant findings in this population is relatively low. Furthermore, our findings support the utilization of the refined Seattle criteria as a sensitive and specific technique for screening pediatric and young-adolescent athletes, further enhancing the accuracy of ECG-based evaluations.

The athlete's heart: insights from echocardiography

The manifestations of the athlete's heart can create diagnostic challenges during an echocardiographic assessment. The classifications of the morphological and functional changes induced by sport participation are often beyond 'normal limits' making it imperative to identify any overlap between pathology and normal physiology. The phenotype of the athlete's heart is not exclusive to one chamber or function. Therefore, in this narrative review, we consider the effects of sporting discipline and training volume on the holistic athlete's heart, as well as demographic factors including ethnicity, body size, sex, and age.

Functional and Morphological Adaptations in the Heart of Children Aged 12-14 Years following Two Different Endurance Training Protocols

This study investigated the cardiac functional and the morphological adaptations because of two endurance training protocols. Untrained children (N = 30, age: 12-14 years) were divided into three groups (N = 10/group). The first group did not perform any session (CONTROL), the second performed ventilatory threshold endurance training (VTT) for 12 weeks (2 sessions/week) at an intensity corresponding to the ventilatory threshold (VT) and the third (IT) performed two sessions per week at 120% of maximal oxygen uptake (VO2max). Two other sessions (30 min running at 55-65% of VO2max) per week were performed in VVT and IT. Echocardiograms (Left Ventricular end Diastolic Diameter, LVEDd; Left Ventricular end Diastolic Volume, LVEDV; Stroke Volume, SV; Ejection Fraction, EF; Posterior Wall Thickness of the Left Ventricle, PWTLV) and cardiopulmonary ergospirometry (VO2max, VT, velocity at VO2max (vVO2max), time in vVO2max until exhaustion (Tlim) was conducted before and after protocols. Significant increases were observed in both training groups in LVEDd (VTT = 5%; IT = 3.64%), in LVEDV (VTT = 23.7%; ITT = 13.6%), in SV (VTT = 25%; IT = 16.9%) but not in PWTLV and EF, after protocols. No differences were noted in the CONTROL group. VO2max and VT increased significantly in both training groups by approximately 9% after training. Our results indicate that intensity endurance training does not induce meaningful functional and morphological perturbations in the hearts of children.

Outcomes of Investigating T Wave Inversion With Echocardiography in an Unselected Young Male Preparticipation Cohort

BACKGROUND Electrocardiography (ECG) may be performed as part of preparticipation sports screening. Recommendations on screening of athletes to identify individuals with previously unrecognized cardiac disease are robust; however, data guiding the preparticipation screening of unselected populations are scarce. T wave inversion (TWI) on ECG may suggest an undiagnosed cardiomyopathy. This study aims to describe the prevalence of abnormal TWI in an unselected young male cohort and the outcomes of an echocardiography-guided approach to investigating these individuals for structural heart diseases, focusing on the yield for cardiomyopathies. METHODS AND RESULTS Consecutive young male individuals undergoing a national preparticipation cardiac screening program for 39 months were studied. All underwent resting supine 12-lead ECG. Those manifesting abnormal TWI, defined as negatively deflected T waves of at least 0.1 mV amplitude in any 2 contiguous leads, underwent echocardiography. A total of 69 714 male individuals with a mean age of 17.9±1.1 years were studied. Of the individuals, 562 (0.8%) displayed abnormal TWI. This was most frequently observed in the anterior territory and least so in the lateral territory. A total of 12 individuals (2.1%) were diagnosed with a cardiomyopathy. Cardiomyopathy diagnoses were significantly associated with deeper maximum TWI depth and the presence of abnormal TWI in the lateral territory, but not with abnormal TWI in the anterior and inferior territories. No individual presenting with TWI restricted to solely leads V1 to V2, 2 inferior leads or both was diagnosed with a cardiomyopathy. CONCLUSIONS Cardiomyopathy diagnoses were more strongly associated with certain patterns of abnormal TWI. Our findings may support decisions to prioritize echocardiography in these individuals.

Protecting the stars of tomorrow: do international cardiovascular preparticipation screening policies account for the paediatric athlete? A systematic review and quality appraisal

OBJECTIVE

(1) Identify and review current policies for the cardiovascular screening of athletes to assess their applicability to the paediatric population and (2) evaluate the quality of these policy documents using the Appraisal of Guidelines for Research & Evaluation II (AGREE II) tool.

DESIGN

Systematic review and quality appraisal of policy documents.

DATA SOURCES

A systematic search of PubMed, MEDLINE, Scopus, Web of Science, SportDiscus and CINAHL.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

An article was included if it was a policy/position statement/guideline/consensus or recommendation paper relating to athletes and cardiovascular preparticipation screening.

RESULTS AND SUMMARY

Of the 1630 articles screened, 13 met the inclusion criteria. Relevance to paediatric athletes was found to be high in 3 (23%), moderate in 6 (46%) and low in 4 (31%), and only 2 provide tailored guidance for the athlete aged 12-18 years. A median 5 related citations per policy investigated solely paediatric athletes, with study designs most commonly being retrospective (72%). AGREEII overall quality scores ranged from 25% to 92%, with a median of 75%. The lowest scoring domains were rigour of development; (median 32%) stakeholder involvement (median 47%) and Applicability (median 52%).

CONCLUSION

Cardiac screening policies for athletes predominantly focus on adults, with few providing specific recommendations for paediatric athletes. The overall quality of the policies was moderate, with more recent documents scoring higher. Future research is needed in paediatric athletes to inform and develop cardiac screening guidelines, to improve the cardiac care of youth athletes.

A New Tool to Aid the Differential Diagnosis of Physiological Remodelling from Cardiac Pathology When Assessing Left Ventricle, Left Atrial and Aortic Structure and Function in Male Arab and Black Paediatric Athletes

Aim: To determine if published Z-scores for left ventricular (LV), left atrial (LA) and aortic structure as well as indices of LV function (Doppler and TDI) in paediatric athletes and non-athletes are appropriate for application in male Arab and black paediatric athletes. If inappropriate, we aim to provide new nomograms and Z-scores for clinical application. Methods: 417 (297 Arab, 120 black) male paediatric (11-18 years) athletes, were evaluated by 2D echocardiography as per British Society of Echocardiography recommendations, and biological age (by radiological X-ray) assessment. Z-scores were tested by residual and correlation analysis together with visual inspection. New Z-scores involved allometric (a*BSA(b+c*chronological age)) and second-order polynomial (y=a*chronological age2+b*chronological age+c) equations for measures of cardiac size and indices of LV function, respectively. Results: Residual linear regression, correlation analysis and visual inspection revealed published z-scores in white peri-pubertal footballers and paediatric non-athletes to be inappropriate for application in male Arab and black paediatric athletes. Residual linear regression revealed new Z-scores for measures of LV, LA and aortic root size to be independent of BSA, ethnicity, chronological and biological age. Residual linear regression revealed new Z-scores for measures of function to be independent of chronological age. Conclusion: Our new z-scores may aid differential diagnosis of suspected pathology versus physiology remodelling, in cardiac screening of the Arab and black paediatric athlete. Nomograms are provided to assist the tracking of the paediatric athlete necessitating annual follow-up and Excel z-score calculation to facilitate use in day-to-day practice.

Young athlete's growing heart: sex differences in cardiac adaptation to exercise training during adolescence

BACKGROUND

Athlete's heart is a condition of exercise-induced cardiac remodelling. Adult male endurance athletes more often remodel beyond reference values. The impact of sex on remodelling through adolescence remains unclear. Paediatric reference values do not account for patient sex or exercise history. We aimed to study the effect of sex on cardiac remodelling throughout adolescence.

METHODS

We recruited 76 male (M) and female (F) 12-year-old cross-country skiers in a longitudinal cohort study. Echocardiography was performed and analysed according to guidelines at age 12 (48 M, 28 F), 15 (34 M, 14 F) and 18 (23 M, 11 F). Repeated echocardiographic measurements were analysed by linear mixed model regression.

RESULTS

Males displayed greater indexed left ventricular end-diastolic volumes (LV EDVi) from age 12 (M 81±7 vs F 76±7, mL/m², p≤0.01), and progressed further until follow-up at age 18 (M 2.3±9.7 vs F -3.9±4.5 ΔmL/m², p≤0.01). LV EDVi remained above adult upper reference values in both groups. Males increased LV Mass Index from age 12 to 18 (M 33±27 vs F 4±19, Δg/m², p≤0.01). Males displayed LV mass above paediatric reference values at ages 15 and 18. A subset of males (35%) and females (25%) displayed wall thickness above paediatric reference values at age 12. Cardiac function was normal. There was no sex difference in exercise hours.

CONCLUSION

Sex-related differences in athlete's heart were evident from age 12, and progressed throughout adolescence. Remodelling beyond reference values was more frequent than previously reported, particularly affecting males. Age, sex and exercise history may assist clinicians in distinguishing exercise-induced remodelling from pathology in adolescents.

Left Ventricular Responses during Exercise in Highly Trained Youth Athletes: Echocardiographic Insights on Function and Adaptation

There is an increase in the prevalence of elite youth sports academies, whose sole aim is to develop future elite athletes. This involves the exposure of the child and adolescent athlete to high-volume training during a period of volatile growth. The large amount of data in this area has been garnered from the resting echocardiographic left ventricular (LV) evaluation of the youth athlete; while this can provide some insight on the functional adaptations to training, it is unable to elucidate a comprehensive overview of the function of the youth athletes' LV during exercise. Consequently, there is a need to interrogate the LV responses in-exercise. This review outlines the feasibility and functional insight of capturing global indices of LV function (Stroke Index-SVIndex and Cardiac Index-QIndex), systolic and diastolic markers, and cardiac strain during submaximal and maximal exercise. Larger SVI and QI were noted in these highly trained young athletes compared to recreationally active peers during submaximal and maximal exercise. The mechanistic insights suggest that there are minimal functional systolic adaptions during exercise compared to their recreationally active peers. Diastolic function was superior during exercise in these young athletes, and this appears to be underpinned by enhanced determinants of pre-load.

Early repolarization in adolescent athletes: A gender comparison of ECG and echocardiographic characteristics

BACKGROUND

The early repolarization pattern (ERp) is an electrocardiographic finding previously associated with arrhythmic risk in adults. The purpose of this study is to evaluate the prevalence and characteristics of ERp in a group of adolescent athletes according to gender. Furthermore, potential associations with clinical, electrocardiographic, and echocardiographic parameters are explored.

METHODS

In this cross-sectional study young athletes (age < 18 years) were consecutively enrolled during the annual pre-participation evaluation, undergoing also transthoracic echocardiography assessment from January 2015 to March 2020.

RESULTS

The prevalence of ERp was 27% in the whole population. Athletes with ERp were more frequently men practicing endurance sports. Women with ERp showed lower heart rate at rest, greater posterior, and relative ventricular wall thickness than those without ERp. Men with ERp presented higher systolic blood pressure at peak exercise, greater septal wall thickness, and indexed left ventricular mass than those without ERp. Both genders with ERp showed increased QRS voltage and narrower QRS duration. The ERp phenotype in men was more frequently notched with higher amplitude and ascending ST segment. Women's ERp presented more frequently a slurred morphology, especially in the inferior leads, and horizontal ST slope. No differences emerged in the occurrence of arrhythmias at rest and during maximal exercise test between groups, even considering higher risk phenotypes.

CONCLUSIONS

ERp is an ECG finding compatible with normal cardiac adaptations to training in young athletes. ERp demonstrated gender differences regarding phenotypes previously associated with increased cardiovascular risk, not showing any differences in arrhythmias during maximal exercise test.

Training intensity influences left ventricular dimensions in young competitive athletes

Background

In young athletes, exercise causes changes in the heart that include growth in wall thickness and mass of the left ventricle and expansion of the heart’s chambers. The heart’s function is either preserved or enhanced, but this may change to the opposite over time.

Objective

This study aimed to assess structural and functional cardiac adaptations in relation to exercise training time, intensity, and performance in young competitive athletes.

Methods

A total of 404 children and adolescents (14.23 ± 2.0 years, 97 females) were enrolled in the Munich Cardiovascular Adaptations in Young Athletes Study (MuCAYA-Study). Eighty-five participants were examined two times a year. Two-dimensional echocardiography was performed to assess left ventricular structure and function. Training time and intensity was measured with the MoMo physical activity questionnaire, maximum aerobic capacity by cardiopulmonary exercise testing, and strength with the handgrip strength test.

Results

Maximum aerobic capacity significantly influenced interventricular septal thickness in diastole. Training intensity significantly influenced left ventricular internal diameter in diastole and systole, and left ventricular mass indexed to body surface area. Within one year, interventricular wall thickness, relative wall thickness and left ventricular mass, indexed to body surface area and height, increased significantly. Training intensity and aerobic capacity contributed to cardiac adaptations in young competitive athletes, as represented by altered structural parameters but preserved cardiac function. Within a year, however, structural changes and a decline in diastolic performance were observed within the longitudinal sub-sample.

Conclusion

Our results confirm the hypothesis that cardiac adaptations to exercise occur at a young age. Cardiac adaptation in our cohort was influenced by exercise intensity and maximum aerobic capacity.

Echocardiographic myocardial work in pre-adolescent male basketball players: a comparison with cardiopulmonary exercise test-derived aerobic capacity

Background: Pressure-strain loop (PSL) analysis provides a novel, less load-dependent non-invasive method to quantify myocardial work and demonstrates a significant correlation with the contractile reserve in adult athletes. We aim to validate PSL-derived markers in characterizing LV function in pre-adolescent basketball players by comparing results before and after the cardiopulmonary exercise test (CPX) and explore its association with CPX-derived aerobic capacity.

Methods: Cardiac morphology and function in 20 pre-adolescent basketball players were assessed at 9.7 years old (9.7 ± 1.1 year) before and after cardiopulmonary exercise testing. Echocardiography was performed in all subjects, including two-dimensional speckle-tracking echocardiography (STE). Simultaneous brachial-cuff-measured blood pressure was recorded to perform PSL analysis.

Results: Nineteen subjects were included in the final analysis. Exercise training in pre-adolescent males was associated with lower global work index (GWI) and global work efficiency (GWE) at rest. GWE at stress was significantly correlated with VO2max and peak O2 pulse (p = 0.0122, r = 0.56; p = 0.00122, r = 0.69, respectively). When indexed by body mass, GWI and GWE both significantly correlated with relative VO2max (p = 0.0086 and 0.0011 respectively, r = 0.58 and 0.69 respectively); GWI and GWE at baseline and stress were all significantly correlated with peak O2 pulse (GWI at baseline, p&lt; 0.0001, r = −0.90; GWE at baseline, p&lt; 0.0001, r = −0.89; GWI at stress, p= 0.0289, r = −0.50; GWE at stress, p&lt; 0.0001, r = −0.83).

Conclusion: PSL-analysis-derived GWI and GWE at rest indexed by body mass are associated with cardiopulmonary exercise test-derived peak oxygen consumption and oxygen pulse in pre-adolescent athletes.

Cardiac Concerns in the Pediatric Athlete

Cardiovascular disease remains the number one cause of death in Americans. It is no secret that exercise mitigates this risk. Exercise and regular physical activity are beneficial for physical health including aerobic conditioning, endurance, strength, mental health, and overall improved quality of life. Unfortunately, today many children and adolescents are sedentary, lacking the recommended daily amount of physical activity, leading to higher rates of obesity, cardiovascular disease, stroke, diabetes, anxiety, and depression. Given this rising concern, the World Health Organization launched a 12-year plan to improve physical activity in children and adolescents by reducing the inactivity rate by 15% in the world. How does this apply to children and adolescents with acquired or congenital heart disease?.

Resting Electrocardiogram and Blood Pressure in Young Athletes and Non-Athletes: A 4-year follow-up

A follow-up data on electrocardiogram (ECG) and blood pressure (BP) changes in adolescent athletes are scarce. We compared ECG and BP between adolescent athletes and non-athletes in a 4-year follow-up. A total of 154 youth sports clubs (SC) in Finland and 100 secondary schools for comparison data participated in this observational follow-up study. Those who maintained or adopted SC participation are referred to as "Always athletes" (n=137), those who never participated in SC as "Never athletes" (n=108) and those who dropped out of SC during the follow-up as "Changers" (n=116). The mean age of the participants was 15.5 (0.6) years in all study groups at baseline. Resting ECG including heart rate, PR interval, QRS duration, QRS axis, QRS amplitude, T axis and QT interval and BP were measured from all participants at baseline and after follow-up. "Always athletes" had lower resting heart rate, more negative T-wave axis and higher QRS amplitude than "Never athletes" at baseline and at 4-years (P < 0.05). "Changers" had lower resting heart rate, more negative T-wave axis and higher QRS amplitude, systolic BP and pulse pressure than "Never athletes" at baseline (P < 0.05). None of the observed differences at baseline, were visible at 4-years (P > 0.05) except the difference in T-wave axis (P = 0.028). The significant group x time interaction between "Changers" and "Never athletes" was found for QRS amplitude (P = 0.017). Adolescent athletes have several training-induced cardiovascular adaptations, which return towards the levels of non-athletes after cessation of regular training. This article is protected by copyright. All rights reserved.

The effect of long-term soccer training on changes in cardiac function during exercise in elite youth soccer players

It is unclear what the effect of long-term, high-volume soccer training has on left ventricular (LV) function during exercise in youth soccer players. This study evaluated changes in LV function during submaximal exercise in a group of highly-trained male soccer players (SP) as they transitioned over a three-year period from pre-adolescent to adolescent athletes. Data were compared to age-and sex-matched recreationally active controls (CON) over the same time period. Twenty-two SP from two professional English Premier League youth soccer academies (age: 12.0 ± 0.3 years at start of the study) and 15 CON (age: 11.7 ± 0.3 years) were recruited. Two-dimensional echocardiography was used to quantify LV function during exercise at the same submaximal metabolic load (approx. 45%VO₂ peak) across the 3 years. After controlling for growth and maturation, there were training-induced changes and superiority (p<0.001) in cardiac index (QIndex) from year 1 in the SP compared to CON. SP (year 1: 6.13 ± 0.76; year 2: 6.94 ± 1.31 and year 3: 7.20 ± 1.81 L/min/m² ) compared to CON (year 1: 5.15 ± 1.12; year 2: 4.67 ± 1.04 and year 3: 5.49 ± 1.06 L/min/m² ). Similar training-induced increases were noted for mitral inflow velocity (E): SP (year 1: 129 ± 12; year 2: 143 ± 16 and year 3: 135 ± 18 cm/s) compared to CON (year 1: 113 ± 10; year 2: 111 ± 12 and year 3: 121 ± 9 cm/s).This study indicated that there was evidence of yearly, training-induced increases in left ventricular function during submaximal exercise independent from the influence of growth and maturation in elite youth SP.

Age-Related Electrocardiographic Characteristics of Male Junior Soccer Athletes

Introduction

Very limited data exist on normal age-related ECG variations in adolescents and no data have been published regarding the ECG anomalies induced by intensive training, which are relevant in pre-participation screening for sudden cardiac death prevention in the adolescent athletic population. The purpose of this study was to establish normal age-related electrocardiographic measurements (P wave duration, PR interval, QRS duration, QT, and QTc interval) grouped according to 2-year age intervals.

Methods

A total of 2,151 consecutive healthy adolescent Soccer athletes (trained for a mean of 7.2 ± 1.1 h per week, 100% male Caucasians, mean age 12.4 ± 1.4 years, range 7–18) underwent pre-participation screening, which included ECG and transthoracic echocardiography in a single referral center.

Results

Their heart rate progressively slowed as age increased (p < 0.001, ranging from 80.8 ± 13.2 to 59.5 ± 10.2 bpm), as expected. The P wave, PR interval, and QRS duration significantly increased in older age classes (p = 0.019, p = 0.001, and p < 0.001, respectively), and after Bonferroni's correction, the difference remained significant in all age classes for QRS duration. The QTc interval diminished progressively with increasing age (p = 0.003) while the QT interval increased progressively (p < 0.001).

Conclusions

Significant variations in the normal ECG characteristics of young athletes exist between different age groups related to increasing age and training burden, thus, age-specific reference values could be adopted, as already done for echocardiographic measurements, and may help to further discriminate potentially pathologic conditions.

Athlete Heart in Children and Young Athletes. Echocardiographic Findings in 331 Cases

The changes of the athlete's heart are not well defined and characterized in children. We aimed to describe the morphological changes of the heart related to sport in young athletes. We evaluated a group of 331 young athletes under 18 years (mean 11.9 ± 3.2) who practice tennis: 58 (16.52%), football: 118 (33.62%), basketball: 16 (4.56%), athletics: 40 (11.4%), and swimming: 99 (28.21%). Type of sport, years of practice, and duration of the training were collected. All children underwent echocardiography with the following M-mode parameters: left atrium diameter (LAD), interventricular septum (IVS), and left ventricle posterior Wall (LVPW), diastolic diameter of the left ventricle (LVDD), and right ventricle outflow tract (RVOT). The major finding of our study was that 20% of the children had a Z score > 2 for the IVS and that increased to 30% for the children playing tennis or swimming. Also, other changes like LA and RVOT dilatation were observed in about 10 and 14% of the cases, respectively. Taken together, these figures indicate that cardiac remodeling is frequent in children. Further studies are needed to establish consensus-based criteria of athlete's heart in young children.

The influence of maturation on exercise-induced cardiac remodelling and haematological adaptation

KEY POINTS

It has long been hypothesised that cardiovascular adaptation to endurance training is augmented following puberty. We investigated whether differences in cardiac and haematological variables exist, and to what extent, between endurance-trained vs. untrained, pre- and post-peak height velocity (PHV) children, and how these central factors relate to maximal oxygen consumption. Using echocardiography to quantify left ventricular (LV) morphology and carbon monoxide rebreathing to determine blood volume and haemoglobin mass, we identified that training-related differences in LV morphology are evident in pre-PHV children, with haematological differences also observed between pre-PHV girls. However, the breadth and magnitude of cardiovascular remodelling was more pronounced post-PHV. Cardiac and haematological measures provide significant predictive models for maximal oxygen consumption in children that are much stronger post-PHV, suggesting that other important determinants within the oxygen transport chain could account for the majority of variance in before puberty.

ABSTRACT

Cardiovascular and haematological adaptations to endurance training facilitate greater maximal oxygen consumption, and such adaptations maybe augmented following puberty. Therefore, we compared left ventricular (LV) morphology (echocardiography), blood volume, haemoglobin (Hb) mass (CO-rebreathe) and in endurance-trained and untrained boys (n = 42, age = 9.0-17.1 years, = 61.6±7.2 mL∙kg∙min, and n = 31, age = 8.0-17.7 years, O_2max = 46.5±6.1 mL∙kg∙min, respectively) and girls (n = 45, age = 8.2-17.0 years, O_2max = 51.4±5.7 mL∙kg∙min and n = 36, age = 8.0-17.6 years, O_2max = 39.8±5.7 mL∙kg∙min, respectively). Pubertal stage was estimated via maturity offset, with participants classified as pre- or post-peak height velocity (PHV). Pre-PHV, only a larger LV end-diastolic volume/lean body mass (EDV/LBM) for trained boys (+0.28 mL∙kg^LBM , P = 0.007) and a higher Hb mass/LBM for trained girls (+1.65 g∙kg^LBM , P = 0.007) were evident compared to untrained controls. Post-PHV, LV mass/LBM (boys:+0.50 g∙kg^LBM , P = 0.0003; girls:+0.35 g∙kg^LBM , P = 0.003), EDV/LBM (boys:+0.35 mL∙kg^LBM , P<0.0001; girls:+0.31 mL∙kgLBM, P = 0.0004), blood volume/LBM (boys:+12.47 mL∙kg^LBM , P = 0.004; girls:+13.48 mL∙kg^LBM , P = 0.0002.) and Hb mass/LBM (boys:+1.29 g∙kg^LBM , P = 0.015; girls:+1.47 g∙kg^LBM , P = 0.002) were all greater in trained vs. untrained groups. Pre-PHV, EDV (R² _adj = 0.224, P = 0.001) in boys, and Hb mass and interventricular septal thickness (R² _adj = 0.317, P = 0.002) in girls partially accounted for the variance in O_2max . Post-PHV, stronger predictive models were evident via the inclusion of LV wall thickness and EDV in boys (R² _adj = 0.608, P<0.0001), and posterior wall thickness and Hb mass in girls (R² _adj = 0.490, P<0.0001). In conclusion, cardiovascular adaptation to exercise training is more pronounced post-PHV, with evidence for a greater role of central components for oxygen delivery. Abstract figure legend: Schematic diagram depicting cardiac structural and haematological differences between trained and untrained boys and girls, pre-peak height velocity (PHV) and post-PHV alongside cardiac and haematological variables contributions to the variance in O_2max . Cardiac and haematological variables are greater in trained vs. untrained pre-pubertal children, and a greater number and magnitude of differences are observed at post-PHV. These variables provide significant predictive models for maximal oxygen consumption in children and are much stronger post-PHV, suggesting that other important determinants within the oxygen transport chain could account for the majority of variance in O_2max before puberty. This article is protected by copyright. All rights reserved.

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

OBJECTIVES

Athletes performing sports on high level are at increased risk for sudden cardiac death. This includes paediatric athletes, even though data on screening strategies in this age group remain scarce. This study aimed to assess electrocardiogram interpretation criteria in paediatric athletes and to evaluate the cost of screening.

METHODS

National, multicentre, retrospective, observational study on 891 athletes of paediatric age (<18 years) evaluated by history, physical examination and 12-lead electrocardiogram. The primary outcome measure was abnormal electrocardiogram findings according to the International Recommendations for Electrographic Interpretation in Athletes. The secondary outcome measure was cost of screening.

RESULTS

19 athletes (2.1%) presented abnormal electrocardiogram findings requiring further investigations, mainly abnormal T-wave inversion. These 19 athletes were predominantly males, performing endurance sports with a mean volume of 10 weekly hours for a mean duration of 6 years of training. Further investigations did not identify any relevant pathology. All athletes were cleared for competition with regular follow-up. Total costs of the screening were 108,860 USD (122 USD per athlete).

CONCLUSIONS

Our study using the International Recommendations for Electrographic Interpretation in Athletes identified a low count of abnormal findings in paediatric athletes, yet raising substantially the cost of screening. Hence, the utility of electrocardiogram-inclusive screening of paediatric athletes remains to be elucidated by longitudinal data.

Implementing the 27 PRISMA 2020 Statement items for systematic reviews in the sport and exercise medicine, musculoskeletal rehabilitation and sports science fields: the PERSiST (implementing Prisma in Exercise, Rehabilitation, Sport medicine and SporTs science) guidance

Poor reporting of medical and healthcare systematic reviews is a problem from which the sports and exercise medicine, musculoskeletal rehabilitation, and sports science fields are not immune. Transparent, accurate and comprehensive systematic review reporting helps researchers replicate methods, readers understand what was done and why, and clinicians and policy-makers implement results in practice. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement and its accompanying Explanation and Elaboration document provide general reporting examples for systematic reviews of healthcare interventions. However, implementation guidance for sport and exercise medicine, musculoskeletal rehabilitation, and sports science does not exist. The Prisma in Exercise, Rehabilitation, Sport medicine and SporTs science (PERSiST) guidance attempts to address this problem. Nineteen content experts collaborated with three methods experts to identify examples of exemplary reporting in systematic reviews in sport and exercise medicine (including physical activity), musculoskeletal rehabilitation (including physiotherapy), and sports science, for each of the PRISMA 2020 Statement items. PERSiST aims to help: (1) systematic reviewers improve the transparency and reporting of systematic reviews and (2) journal editors and peer reviewers make informed decisions about systematic review reporting quality.

The 12-lead electrocardiogram of the elite female footballer as defined by different interpretation criteria across the competitive season

ABSTRACTPre-participation screening (PPS), using a 12-lead electrocardiogram (ECG), is recommended to identify athletes at risk of sudden cardiac death (SCD). ECG interpretation criteria have been developed to address the concern arising from high false-positives in athletes. There are limited ECG data in elite female footballers. The aims of this study were to (1) compare the ECG outcomes using three published ECG criteria (European Society of Cardiology [ESC], Seattle, International) in elite female footballers and (2) compare ECG data at three different stages of a competitive season. Eighty-one elite female footballers (21 ± 4 yr) completed a medical assessment, anthropometrics, resting blood pressure and a resting 12-lead ECG. Each 12-lead ECG was interpreted in accordance with (1) ESC; (2) Seattle; (3) International Criteria to determine training-related and non-training-related ECG changes. A subset of thirteen (26 ± 4 yr) footballers had repeated resting ECG tests at three time points across the competitive season. Eighty percent of females had training-related ECG patterns. Sinus bradycardia (65%) and early repolarization (42%) were the most common. Using the ESC Criteria 25% (20/81) of the athletes were considered to have an abnormal ECG, compared to 0% using the Seattle and International Criteria, mainly due to alterations in QT length criteria. There were no clinically significant differences in ECG data across a competitive season. The Seattle and International ECG Criteria significantly reduced the number of ECG false-positives in elite female footballers and the time point of PPS within a competitive season is unlikely to alter the PPS outcomes.Abbreviations: AMSSM: American Medical Society for Sports Medicine; ANOVA: Analysis of Variance; BSA: Body Surface Area; ECG: Electrocardiogram; ESC: European Society of Cardiology; FA: Football Association; FIFA: The Fédération Internationale de Football Association (FIFA); F-MARC: FIFA Medical Assessment and Research Centre; LAE: Left atrial enlargement; LVH: Left ventricular hypertrophy; PPS: Pre-participation screening; SCD: Sudden cardiac death.

Early Repolarization in Pediatric Athletes: A Dynamic Electrocardiographic Pattern With Benign Prognosis

Background

Early repolarization pattern (ERP) is considered a common training‐related and benign ECG finding in young adult athletes. Few data exist on ERP in the pediatric athletes population. Therefore, we aimed to evaluate the ERP prevalence, characteristics, and prognosis in pediatric athletes aged ≤16 years.

Methods and Results

Eight‐hundred eighty‐six consecutive pediatric athletes engaged in 17 different sports (mean age, 11.7±2.5 years; 7–16 years) were enrolled and prospectively evaluated with medical history, physical examination, resting and exercise ECGs, and transthoracic echocardiography during their preparticipation screening. Known cardiovascular diseases associated with sudden cardiac death was considered exclusion criteria. Athletes were followed up yearly for 4 years. The prevalence of ERP was 117 (13.2%), equally distributed in both sexes (P=0.072), irrespectively of body mass index and classification of sports. The most common ERP localizations were inferolateral and inferior leads (53.8% and 27.3%, respectively). Notching J‐point morphology was the most prevalent (70%), and rapidly ascending ST elevation (96%) was the most common ST‐segment morphology. Athletes with ERP were older (P<0.001) had lower rest and recovery heart rates (P<0.001), increased precordial and limb R‐wave voltages (P<0.001), increased R/S Sokolow index (P<0.001), and longer PR interval (P=0.006) in comparison with the athletes without ERP. Neither major cardiovascular nor arrhythmic events, nor sudden cardiac death were recorded over a median follow‐up of 4.2 years. One hundred seventeen (80.3%) athletes with ERP exhibited a persistent ERP. ERP localization and J‐point morphology changed during follow‐up in 11 (11.7%) and 17 (18%) of athletes, respectively.

Conclusions

ERP is common in pediatric athletes. It was mostly located in the inferolateral leads and associated with concave ascending ST segment with other training‐related ECG changes. The lack of either sudden cardiac death or cardiomyopathies linked to sudden cardiac death over follow‐up suggests that in pediatric athletes, ERP may be considered a benign training‐related ECG phenomenon with a potential dynamic pattern.

Assessment of a Novel, 22-lead Mobile Electrocardiogram in Elite, Adolescent Footballers

The 12-lead electrocardiogram is a key component of cardiac screening in elite adolescent footballers. Current technology hampers mobile electrocardiogram monitoring that could reduce the time-to-diagnosis in symptomatic athletes. Recently, a 22-lead mobile electrocardiogram monitor, CardioSecur (Personal MedSystems GmbH), has been approved for use in adults. In this study, the differences in parameter accuracy between CardioSecur's 22-lead electrocardiogram and the gold standard 12-lead electrocardiogram were assessed in elite adolescent footballers (n=31) using Bland-Altman and paired t-tests/Wilcoxon analysis. Agreement between the two devices was clinically acceptable for heart rate (bias=- 0.633 bpm), PR Interval (bias=- 1.73 ms), Bazzett's corrected QTc interval (bias=2.03 ms), T-wave axis (bias=6.55°), P-wave duration (bias=- 0.941 ms), Q-wave amplitude (bias=0.0195 mV), Q-wave duration (bias=1.98 ms), rhythm (bias=0.0333), ST-segment (bias=- 0.0629), J-point analysis (bias=- 0.01) and extended T wave and QRS duration analysis. Unsatisfactory agreement was observed in QRS axis (bias=- 19.4°), P-wave axis (bias=- 0.670°), QRS amplitude (bias=- 0.660 mV), P-wave amplitude (bias=0.0400 mV) and T-wave amplitude (bias=- 0.0675 mV). CardioSecur's 22-lead electrocardiogram agrees with the gold standard in rhythm, durations, T-wave determination in all leads assessed, permitting its use in adolescent footballers for immediate pitch- or track-side analysis.

Impact of early sports specialisation on paediatric ECG

Athletes of pediatric age are growing in number. They are subject to a number of risks, among them sudden cardiac death (SCD). This study aimed to characterize the pediatric athlete population in Switzerland, to evaluate electrocardiographic findings based on the International Criteria for electrocardiography (ECG) Interpretation in Athletes, and to analyze the association between demographic data, sport type, and ECG changes. Retrospective, observational study of pediatric athletes (less than 18 years old) including medical history, physical examination, and a 12-lead resting ECG. The primary focus was on identification of normal, borderline, and abnormal ECG findings. The secondary observation was the relation between ECG and demographic, anthropometric, sport-related, and clinical data. The 891 athletes (mean 14.8 years, 35% girls) practiced 45 different sports on three different levels, representing all types of static and dynamic composition of the Classification of Sports by Mitchell. There were 75.4% of normal ECG findings, among them most commonly early repolarization, sinus bradycardia, and left ventricular hypertrophy; 4.3% had a borderline finding; 2.1% were abnormal and required further investigations, without SCD-related diagnosis. While the normal ECG findings were related to sex, age, and endurance sports, no such observation was found for borderline or abnormal criteria. Our results in an entirely pediatric population of athletes demonstrate that sex, age, and type of sports correlate with normal ECG findings. Abnormal ECG findings in pediatric athletes are rare. The International Criteria for ECG Interpretation in Athletes are appropriate for this age group.

Pediatric athletes' ECG and diagnostic performance of contemporary ECG interpretation criteria

BACKGROUND

Electrocardiographic (ECG) pre-participation screening(PPS) can prevent sudden cardiac death(SCD) but the Interpretation of the athlete's ECG is based on specific criteria addressed for adult athletes while few data exist about the pediatric athlete's ECG. We aimed to assess the features of pediatric athletes' ECG and compared the diagnostic performance of 2017 International ECG recommendation, 2010 European Society of Cardiology recommendation and 2013-Seattle criteria in detecting clinical conditions at risk of SCD.

METHODS

886 consecutive pediatric athletes (mean age 11.7 ± 2.5 years; 7-16-years) were enrolled and prospectively evaluated with medical history, physical examination, resting and exercise ECG and transthoracic echocardiography during their PPS.

RESULTS

The most common physiological ECG patterns in pediatric athletes were isolated left ventricular hypertrophy criteria (26.9%), juvenile T-wave pattern (22%) and early repolarization pattern (13.2%). The most frequent borderline abnormalities were left axis deviation (1.8%) and right axis deviation (0.9%) while T-wave inversion (0.8%) especially located in inferior leads (0.7%) was the most prevalent abnormal findings. Seven athletes (0.79%) were diagnosed with a condition related to SCD. Compared to Seattle and ESC, the International improved ECG specificity (International = 98% ESC = 64% Seattle = 95%) with lower sensitivity (ESC and Seattle 86%vs International 57%). The false-positive rate decreases from 36% of ESC to 2.2% of International but the latter showed a higher false-negative rate(0.34%).

CONCLUSION

Pediatric athletes like the adult counterpart exhibit a high prevalence of ECG abnormalities mostly representing training-related ECG adaptation. The International criteria showed a lower false-positive rate but at the cost of loss of sensitivity.

Improved Carotid Elasticity but Altered Central Hemodynamics and Carotid Structure in Young Athletes

Young athletes most often exceed the physical activity recommendations of the World Health Organization. Therefore, they are of special interest for investigating cardiovascular adaptions to exercise. This study aimed to examine the arterial structure and function of young athletes 12-17 years old and compare these parameters to reference values of healthy cohorts. Carotid intima-media thickness (cIMT), carotid diameter, cIMT÷carotid diameter-ratio (cIDR), arterial compliance (AC), elastic modulus (Ep), β stiffness index (β), and carotid pulse wave velocity (PWVβ) were determined using ultrasound in 331 young athletes (77 girls; mean age, 14.6 ± 1.30 years). Central systolic blood pressure (cSBP) and aortic PWV (aPWV) were measured using the oscillometric device Mobil-O-Graph. Standard deviation scores (SDS) of all parameters were calculated according to German reference values. The 75th and 90th percentiles were defined as the threshold for elevated cIMT and arterial stiffness, respectively. Activity behavior was assessed with the MoMo physical activity questionnaire, and maximum power output with a standard cardiopulmonary exercise test. One-sample t-tests were performed to investigate the significant deviations in SDS values compared to the value "0". All subjects participated in competitive sports for at least 6 h per week (565.6 ± 206.0 min/week). Of the 331 young athletes, 135 (40.2%) had cIMT >75th percentile, 71 (21.5%) had cSBP >90th percentile, and 94 (28.4%) had aPWV>90th percentile. We observed higher cIMT SDS (p < 0.001), cIDR SDS (p = 0.009), and AC SDS (p < 0.001) but lower β SDS (p < 0.001), Ep SDS (p < 0.001), and PWVβ SDS (p < 0.001) compared to the reference cohort. The cSBP SDS (p < 0.001) and aPWV SDS (p < 0.001) were elevated. In conclusion, cIMT and cIDR were higher in young athletes than in a reference cohort. Furthermore, young athletes presented better carotid elasticity and lower arterial stiffness of the carotid artery. However, central arterial stiffness was higher compared to the reference cohort. The thickening of the carotid intima-media complex in combination with a reduction in arterial stiffness indicates a physiological adaptation to exercise in youth.

Recommendations on Youth Participation in Ultra-Endurance Running Events: A Consensus Statement

Participation in ultra-endurance running (UER) events continues to grow across ages, including youth athletes. The 50- and 100-km are the most popular distances among youth athletes. Most youth athletes are between 16-18 years; however, some runners younger than 12 years have successfully completed UER events. Parents, athletes, coaches, race directors, and medical professionals often seek advice regarding the safety of youth athletes participating in these events, especially with regard to potential short and long-term health consequences. UER may impact key organ systems during growth and development. We propose a decision-making process, based on current knowledge and the experience of the consensus group that addresses age regulations, medical and psychological well-being, training status and race-specific factors (such as distance, elevation change, remoteness, ambient temperatures, level of medical assistance, and type of provisions provided by the race organizers) to use until evidence of long-term consequences of UER in youth athletes is available. These recommendations are aimed at safe participation in UER events for youth athletes with a proper and individualized assessment.

Coronary artery z score values in adolescent elite male soccer players

BACKGROUND

With the increased training loads at very early ages in European elite youth soccer, there is an interest to analyse coronary artery remodelling due to high-intensity exercise.

DESIGN AND METHODS

Prospective echocardiographic study in 259 adolescent elite male soccer players and 48 matched controls.

RESULTS

The mean age was 12.7 ± 0.63 years in soccer players and 12.6 ± 0.7 years in controls (p > 0.05). Soccer players had significant greater indexed left ventricular mass (93 ± 13 g/m2 versus 79 ± 12 g/m2, p = 0.001). Both coronary arteries origin could be identified in every participant. In soccer players, the mean diameter of the left main coronary artery was 3.67 mm (SD ± 0.59) and 2.61 mm (SD ± 0.48) for right main coronary artery. Controls showed smaller mean luminal diameter (left main coronary artery, p = 0.01; right main coronary artery, p = 0.025). In soccer players, a total of 91% (n = 196) and in controls a total of 94% (n = 45) showed left main coronary artery z scores within the normal range: -2.0 to 2.0. In right main coronary artery, a pattern of z score values distribution was comparable (soccer players 94%, n = 202 vs. controls 84%, n = 40). A subgroup of soccer players had supernormal z score values (>2.0 to 2.5) for left main coronary artery (9%, n = 19, p = 0.01) and right main coronary artery (6%, n = 10, p = 0.025), respectively.

CONCLUSION

Elite soccer training in early adolescence may be a stimulus strong enough to develop increased coronary arteries diameters. In soccer players, a coronary artery z score >2.0-2.5 might reflect a physiologic response induced by multiannual high-intensity training.

Assessment of Structure, Function, and Rhythm of the Heart with Echocardiography and Electrocardiography in Adolescent Swimmers

The aim of this study was to evaluate the cardiac parameters by using electrocardiography and echocardiography in adolescent swimmers. Twenty-two adolescent swimmers and 22 gender- and age-matched sedentary controls admitted to our center between November 2018 and May 2019 were included in this study. In addition to demographical characteristics, participants were assessed via a 12-lead electrocardiography and two-dimensional echocardiography for cardiac function. On the echocardiography, end-systolic and end-diastolic interventricular septum, end-systolic and end-diastolic left ventricular posterior wall thicknesses, left atrial width, Tricuspid E, left ventricular mass and left ventricular mass index were higher in the swimmers when compared to the sedentary controls (P < 0.05). On the electrocardiography, Tp-e duration which reflects ventricular transmural repolarization, and Tp-e/QT and Tp-e/corrected QT ratios were higher in the swimmers than the sedentary controls (P < 0.05). In conclusion, swimming exercise in children leads to concentric thickening of left ventricle and induces an increase in Tp-e duration, and Tp-e/QT and Tp-e/corrected QT ratios, which are the novel markers for risk of ventricular arrhythmias.

The determinants of positivisation of anterior T-wave inversion in children

BACKGROUND

Anterior T-wave inversion (aTWI) can be a common electrical sign in cardiomyopathies but also a benign feature regressing with age in healthy children. Unfortunately, little is known about the age of positivisation of aTWI and its determinants in children and longitudinal data are not available. The aim of this longitudinal study was to identify the age and determinants of positivisation of aTWI in healthy children.

METHODS

ATWI was observed in 331 healthy children. They were evaluated yearly until positivisation for a maximum period of 4 years. Positivisation of aTWI was observed in 312 children (94%). The weight, height/length and their respective percentiles at birth and at the time of positivisation of aTWI and weeks of gestation at birth were collected.

RESULTS

Positivisation of aTWI occurred at a mean age of 13.0±2.0 years. When aTWI became positive, the majority of children had a height between 51° and 75° or over the 75° percentile. At the multivariate logistic regression analysis height, weight, percentiles of height and weight at the time of positivisation were identified as the strongest independent predictors of the positivisation of aTWI. No correlation was found for prematurity and anthropometrics characteristics at birth.

CONCLUSIONS

ATWI is a common feature of pediatric ECG, usually regressing with age. Height, weight, percentiles of height and weight at the time of positivisation were identified as determinants of TWI positivisation. These simple anthropometric characteristics should be used in addition to chronological age in order to interpret aTWI in children.

Athlete's Heart in Elite Sport Climbers: Cardiac Adaptations Determined Using ECG and Echocardiography Data

INTRODUCTION

Sudden cardiac death in a young athlete is the leading cause of mortality in athletes during sport. Specific knowledge about cardiac adaptations are necessary for a better understanding of the underlying causes of such events.

METHODS

A retrospective analysis of the electrocardiogram and echocardiographic data obtained during the yearly medical examination of the entire German junior national climbing team was undertaken. First, data from 1 examination were used. In a second step, data from 2 examinations spaced 2 y apart were analyzed for a selected subgroup to gain more knowledge about adaptations to climbing. The data from the subgroup were compared to an age- and sex-matched control group of Nordic skiers from the German junior national Nordic skiing team.

RESULTS

Forty-seven young climbers (20 girls, 27 boys) were examined once. There were no pathological findings in the electrocardiogram or echocardiography. The left ventricular (LV) measurements fell between those for athletes and nonathletes. Eight boys and 6 girls from this group were tested twice over a timeframe of 27.5 mo. All LV measurements increased over time. After 2 y, the measurements from the climbers were comparable to those of the Nordic skiers.

CONCLUSIONS

Hypertrophic cardiomyopathy (hypertrophy of the LV) is the leading cause of sudden cardiac death in athletes. An increase in LV dimensions was observed in the young climbers in this study. LV dimensions being comparable to high-level Nordic skiers after 2 y in the national team imply structural changes over time in this cohort.

Youth running consensus statement: minimising risk of injury and illness in youth runners

Despite the worldwide popularity of running as a sport for children, relatively little is known about its impact on injury and illness. Available studies have focused on adolescent athletes, but these findings may not be applicable to preadolescent and pubescent athletes. To date, there are no evidence or consensus-based guidelines identifying risk factors for injury and illness in youth runners, and current recommendations regarding suitable running distances for youth runners at different ages are opinion based. The International Committee Consensus Work Group convened to evaluate the current science, identify knowledge gaps, categorise risk factors for injury/illness and provide recommendations regarding training, nutrition and participation for youth runners.

Characterisation of LV myocardial exercise function by 2-D strain deformation imaging in elite adolescent footballers

Purpose

Few data exist on the descriptions of LV myocardial mechanics and reserve during dynamic exercise of adolescent athletes. The aim of this study was to describe the LV myocardial and cardiopulmonary changes during exercise using 2-D strain deformation imaging.

Methods

Elite adolescent male football players (n = 42) completed simultaneous cardiopulmonary exercise testing (CPET) and exercise echocardiography measurement of LV myocardial deformation by 2-D strain imaging. LV longitudinal and circumferential 2-D strain and strain rates were analyzed at each stage during incremental exercise to a work rate of 150 W. Additionally, exercise LV myocardial deformation and its relation to metabolic exercise parameters were evaluated at each exercise stage and in recovery using repeated measures ANOVA, linear regression and paired t tests.

Results

LV peak systolic baseline 2-D strain (longitudinal: − 15.4 ± 2.5%, circumferential: − 22.5 ± 3.1%) increased with each exercise stage, but longitudinal strain plateaued at 50 W (mean strain reserve − 7.8 ± 3.0) and did not significantly increase compared to subsequent exercise stages (P > 0.05), whilst circumferential strain (mean strain reserve − 11.6 ± 3.3) significantly increased (P < 0.05) throughout exercise up to 150 W as the dominant mechanism of exercise LV contractility increase. Regression analyses showed LV myocardial strain increased linearly relative to HR, VO₂ and O₂ pulse (P < 0.05) for circumferential deformation, but showed attenuation for longitudinal deformation.

Conclusion

This study describes LV myocardial deformation dynamics by 2-D strain and provides reference values for LV myocardial strain and strain rate during exercise in adolescent footballers. It found important differences between LV longitudinal and circumferential myocardial mechanics during exercise and introduces a methodology that can be used to quantify LV function and cardiac reserve during exercise in adolescent athletes.

Young athletes' ECG: Incomplete right bundle branch block vs crista supraventricularis pattern

BACKGROUND

Incomplete right bundle branch block (IRBBB) is prevalent among athletes, but its etiology remains to be clearly elucidated and the commonly advocated mechanism, an intraventricular conduction delay, does not explain all cases. In the general population, an apparently similar phenomenon but with different pathophysiology and potential consequences, "crista supraventricularis pattern" (CSP, defined as QRS ≤ 100 ms, S wave <40 ms in I or V6 together with an RSR´ pattern in lead-V1) has been described. Yet, this manifestation has not been studied in athletes. Given that IRBBB can be associated with some serious conditions (including Brugada syndrome, arrhythmogenic cardiomyopathy, or atrial septal defects) the differentiation between IRBB and CSP could enhance the accuracy of the pre-participation screening (PPS). We thus aimed to determine the prevalence of CSP in young athletes.

METHODS

Observational study of standard 12-lead resting ECG in a cohort of children (5-16 years) attending a PPS program (August 2018-May 2019).

RESULTS

6,401 children (mean ± SD age 11.2 ± 2.9 years, 99.2% Caucasian, 93.8% male, 97.2% soccer players) were studied. We found CSP in 850 participants (prevalence = 13.3% [95% confidence interval 12.5-14.1]) whereas 553 (8.6%) had IRBBB. The proportion of athletes showing an S1S2S3 pattern was higher in those with CSP compared with the other QRS morphologies (P < .05).

CONCLUSIONS

CSP might have been overlooked in previous reports of sports PPS for children and misdiagnosed as IRBBB, as the proportion of the former condition was higher. Our findings might add useful information to improve the interpretation of the young athletes' ECG and thus the diagnostic value of PPS.

Impact of endurance exercise on the heart of cyclists: A systematic review and meta-analysis

OBJECTIVE

To compare heart structure and function in endurance athletes relative to participants of other sports and non-athletic controls in units relative to body size. A secondary objective was to assess the association between endurance cycling and cardiac abnormalities.

PATIENTS AND METHODS

Five electronic databases (CINAHL, Cochrane Library, Medline, Scopus, and SPORTdiscus) were searched from the earliest record to 14 December 2019 to identify studies investigating cardiovascular structure and function in cyclists. Of the 4865 unique articles identified, 70 met inclusion criteria and of these, 22 articles presented 10 cardiovascular parameters in units relative to body size for meta-analysis and five presented data relating to incidence of cardiac abnormalities. Qualitative analysis was performed on remaining data. The overall quality of evidence was assessed using GRADE. Odds ratios were calculated to compare the incidence of cardiac abnormality.

RESULTS

Heart structure was significantly larger in cyclists compared to non-athletic controls for left ventricular: mass; end-diastolic volume, interventricular septal diameter and internal diameter; posterior wall thickness, and end-systolic internal diameter. Compared to high static and high dynamic sports (e.g., kayaking and canoeing), low-to-moderate static and moderate-to-high dynamic sports (e.g., running and swimming) and moderate-to-high static and low-to-moderate dynamic sports (e.g., bodybuilding and wrestling), endurance cyclists end-diastolic left ventricular internal diameter was consistently larger (mean difference 1.2-3.2 mm/m²). Cardiac abnormalities were higher in cyclists compared to controls (odds ratio: 1.5, 95%CI 1.2-1.8), but the types of cardiac abnormalities in cyclists were not different to other athletes.

CONCLUSION

Endurance cycling is associated with a larger heart relative to body size and an increased incidence of cardiac abnormalities relative to controls.

The adolescent athlete's heart; A miniature adult or grown-up child?

The systematic development of early age talent in sports academies has led to the professionalization of pediatric sport and the sports physician need to be aware of pediatric cardiological problems. Research into the medical cardiac care and assessment of the pediatric athlete are accumulating, but specific pediatric international guidelines are not available yet and reference data for ECG and echocardiography are incomplete, in particular for the age group <12 years of age. This article is an introduction to the physiological and diagnostics specifics of the pediatric athlete. The focus lies in the differences in presentation and diagnosis between pediatric and adult athletes for the most common pathologies. Reference data for electrical and structural adaptations to intensive exercise are sparse particularly in athletes aged below 12 years old. Training related changes include decrease of resting heart rate, increase of cardiac output, ventricular cavity size, and wall thickness. Cardiac hypertrophy is less pronounced in pediatric athletes, as HR mediated cardiac output increase to endurance exercise is the dominant mechanism in peripubertal children. As in adults, the most pronounced cardiovascular adaptations appear in classical endurance sports like rowing, triathlon, and swimming, but the specifics of pediatric ECG and echocardiographic changes need to be considered.