Long-term follow-up of early repolarization pattern in elite athletes

Cardiac Morphofunctional Characteristics of Individuals with Early Repolarization Pattern: A Literature Review

The early repolarization pattern (ERP) is an electrocardiographic phenomenon characterized by the appearance of a distinct J-wave or J-point elevation at the terminal part of the QRS complex. ERP is associated with an increased risk of ventricular arrhythmias in susceptible individuals. The cardiac morphofunctional parameters in subjects with ERP have been characterized mainly by imaging techniques, which suggests that certain changes could be identified in the background of the electrical pathomechanism: however, in this regard, current data are often contradictory or insufficiently detailed. For clarification, a more comprehensive cardiac imaging evaluation of a large patient population is necessary. This review summarizes and analyses the data from the literature related to cardiac morphofunctional characteristics in individuals with ERP.

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.

Electrocardiographic Findings in Professional Male Athletes

OBJECTIVE

To generate granular normative electrocardiogram (ECG) data and characterize the variation by ethnicity and sport played.

DESIGN

Cross-sectional study; ECGs were collected from preseason screening programs from 2012 to 2019 and interpreted in accordance with athlete-specific guidelines.

SETTING

Of the professional athletes based in Vancouver, the North Shore Heart Centre performs the annual preparticipation ECG screening.

PARTICIPANTS

Seven hundred fifty-three professional male athletes competing in hockey, football, lacrosse, skiing, and snowboarding.

INTERVENTIONS

Independent variables include commonly transcribed electrocardiographic findings, for example, those indicating benign and pathologic findings.

MAIN OUTCOME MEASURES

Prevalence of and variance in electrocardiographic findings by sport played and ethnicity.

RESULTS

Of the 753 athletes, 171 (22.3%) were National Hockey League, 358 (47.5%) were Canadian Football League, 163 (21.6%) were Major League Soccer and/or the Canadian National Soccer team, and 61 (8%) others. The most common finding, sinus bradycardia, was more likely in both soccer (P < 0.001) and hockey (P < 0.001) versus football players. Early repolarization (ER) was more likely in soccer players versus both hockey (P < 0.001) and football players (P = 0.001). Within football, Black athletes (BA) were more likely than White athletes to display ER (P = 0.009), left ventricular hypertrophy (P = 0.004), and nonspecific ST changes (P = 0.027).

CONCLUSION

Our study contributes to the generation of normative data for ECG findings while accounting for ethnic and sport-specific variation. The expected clinical presentation of endurance athletes, including soccer players, and the possible predisposition of BA to develop distinct adaptations can augment clinical care by delineating physiology from pathologic changes.

Why Is There an Increased Risk for Sudden Cardiac Death in Patients With Early Repolarization Syndrome?

The last two decades have changed the viewpoint on early repolarization syndrome (ERS). The prevalence of the early repolarization pattern is variable and ranges between 3-24% depending upon age, gender, and criteria used for J-point upliftment from baseline (0.05mV vs. 1 mV). While this pattern was previously linked with a benign result, multiple recent investigations have found a link between early repolarization and Sudden Cardiac Death (SCD) by causing life-threatening arrhythmias like Ventricular tachycardia/Ventricular fibrillation, a condition known as early repolarization syndrome. The syndrome falls under a broader bracket of J wave syndromes, which can be caused by early repolarization or depolarization abnormalities. The characteristics of early repolarization that are considered high risk for Sudden Cardiac Death include the amplitude of J-point upliftment from baseline ( > 0.2 mV), Inferior-lateral location of Early Repolarization pattern, and horizontal and downsloping ST-segment. Patients with symptomatic early repolarisation patterns on ECG are more likely to have repeated cardiac episodes. Implantable Cardioverter-Defibrillator (ICD) implantation and isoproterenol are the recommended treatments in symptomatic patients. On the other hand, asymptomatic patients with early repolarization patterns are prevalent and have a better outcome. Risk categorization is still obscure in asymptomatic early repolarization patterns. This traditional review outlines the known knowledge of pathophysiology behind the increased risk of sudden cardiac death, risk stratification of patients with ERS, and the treatment guidelines for patients with ERS. Further prospective studies are recommended to elucidate the exact mechanism for ventricular arrhythmogenesis in ERS patients and to risk stratifying asymptomatic patients with ERS.

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.

Evaluation of the Seattle and International Criteria in elite Nigerian athletes

BACKGROUND

The Seattle Criteria (SC) and International Criteria (IC) were both developed for cardiovascular pre-participation screening in young athletes. Neither set of Criteria has been systematically evaluated in high level indigenous black African athletes.

OBJECTIVES

(1) To determine the pattern of ECG findings in athletes of the University of Port Harcourt, Nigeria; (2) To determine the predictors of altered repolarization in these athletes; and (3) To evaluate the diagnostic performance of the SC and IC in these athletes.

METHODS

77 athletes (42 males, 35 females) without any known cardiovascular disease were recruited alongside 78 similarly healthy non-athletic controls (44 males, 34 females). The two groups were matched for age, sex, and body mass index. Clinical assessment was according to the Lausanne Recommendations. All subjects underwent electrocardiography and echocardiography. Analysis with the IC was retrospective.

RESULTS

The most common physiological finding in the athletes was sinus bradycardia (n = 37; 48.1%). Early repolarization pattern, ERP (n = 27, 35.1% with SC; n = 42, 54.5% with IC), and dome-shaped ST-segment elevation with T-wave inversion (DSSTWI) in leads V1-4 (n = 21, 29.3% with both criteria), were also prevalent. Compared to controls, only male sex (adjusted odds ratio 2.89, 1.05 to 7.97, p = .040 with SC; OR 2.57, 1.19 to 5.53, p = .016 with IC) and ECG LVH (OR 2.82, 1.18 to 6.75, p = .020 with SC alone) independently predicted ERP, while athletic status (OR 4.76, 1.66 to 13.68, p = .004 with both criteria) alone had a significant multivariate association with DSSTWI. Three athletes (3.9%) had abnormal ECGs while two (2.6%) had major echocardiographic abnormalities. The sensitivity, specificity and accuracy of the SC for structural cardiac disease in the athletes were 50.0% (1.3 to 98.7), 97.3% (90.7 to 99.7) and 96.1% (89.0 to 99.2) respectively. The respective figures for the IC were 50.0% (1.3 to 98.7), 98.7% (92.8 to 100) and 97.4% (90.9 to 99.7).

CONCLUSION

Both criteria showed high accuracy in this Black African cohort with a high frequency of electrocardiographic repolarization changes. While ERP seems to be primarily related to black ethnicity, DSSTWI appears to be a bona fide marker of Athlete's Heart in blacks.

Early repolarization pattern in adult females with eating disorders

INTRODUCTION

The risk of cardiovascular death is increased in patients with eating disorders (ED), but the background for this is unknown. Early repolarization pattern (ERP) on the electrocardiogram (ECG) has been associated with increased risk of sudden cardiac death.

METHODS

We investigated the prevalence of ERP in 233 female patients with anorexia nervosa (AN) and bulimia nervosa (BN) (age 18-35 years) compared with 123 healthy female controls.

RESULTS

Early repolarization pattern was present in 52 (22%) of ED patients (16 (15%) AN patients and 36 (29%) BN patients) and 17 (14%) of healthy controls. When adjusting for age, BMI, heart rate, use of selective serotonin reuptake inhibitors (SSRI), and potassium level, the odds ratio (OR) for ERP was 2.1 (95% CI 1.1-4.2, p = .03). There was an increased prevalence of inferolateral ERP in patients with ED compared with healthy controls (OR = 4.3, 95% CI 1.7-11.3, p = .003) as well as ERP with a downward/horizontal sloping ST segment (OR = 3.1, 95% CI 1.3-7.6, p = .01). Additionally, J-point elevation >0.2 mV was more prevalent in patients with ED (OR = 3.3, 95% CI 1.1-9.7, p = .03).

CONCLUSION

The prevalence of ERP was increased in patients with ED compared with healthy controls. This finding may provide a possible explanation for the increased cardiovascular mortality in ED patients.

Worldwide prevalence of early repolarization pattern in general population and physically active individuals: A meta-analysis

BACKGROUND

The early repolarization pattern (ERP) has recently been associated with cardiac events such as ventricular arrhythmias and sudden cardiac death. However, estimates of the prevalence of ERP vary widely, especially between the general population and physically active individuals. We performed this systematic review and meta-analysis to quantitatively evaluate the worldwide prevalence of ERP in the general population and physically active individuals.

METHODS

We thoroughly searched the PubMed, EMBASE, Web of science, the Cochrane Library, and Scopus databases for relevant studies published until December 20, 2020. Studies in which prevalence was presented or could be estimated from eligible data were included. The pooled prevalence was analyzed using a random-effect model.

RESULTS

Finally, we included 29 studies (182,135 subjects) in the general population and 14 studies (8087 subjects) in the physically active individuals. The worldwide pooled prevalence of ERP in the general population was 11.6% (95% confidence interval [CI]: 10.0%-13.3%). The incidence of ERP was 17.0% and 6.2% in men and women, respectively. The prevalence was 20.9% in blacks, 13.4% in Asians, and 10.1% in Caucasians. Additionally, the prevalence of ERP in physically active individuals was 33.9% (95% CI: 25.3%-42.6%).

CONCLUSION

A significant difference in the worldwide prevalence of ERP is revealed in this study. The ERP is highly prevalent in men, blacks, and physically active individuals.

Early repolarisation among athletes

Objectives

Traditionally, early repolarisation (ER) is considered a benign ECG variant, predominantly found in youths and athletes. However, a limited number of studies have reported an association between ER and the incidental occurrence of ventricular fibrillation or sudden cardiac death. Yet definite, direct comparisons of the incidence of ER in unselected, contemporary populations in athletes as compared with non-athletes and across different sports are lacking. This study therefore aimed to investigate whether ER is more common among athletes as compared with non-athletes, and if ER patterns differ between sport disciplines based on static and dynamic intensity.

Methods

To assess ER we retrospectively analysed ECGs of 2241 adult subjects (2090 athletes, 151 non-athletes), who had a sports medical screening between 2010 and 2014 in an outpatient clinic. The outcome was tested for confounders in a multivariable logistic regression analysis.

Results

ER was found in 502 athletes (24%). We found a 50% higher prevalence of ER in the athlete group compared with the control group (OR 1.5 (SE 0.34), adjusted 95% CI 1.0 to 2.4) in multivariable analysis. A 30% higher prevalence of ER in the inferior leads only (OR 1.3 (SE 0.38), adjusted 95% CI 0.74 to 2.3), a 120% higher prevalence of ER in the lateral leads only (OR 2.2 (SE 1.0), adjusted 95% CI 0.87 to 5.4), and a 20% higher prevalence of ER in the inferior and lateral leads (OR 1.2 (SE 0.49), adjusted 95% CI 0.55 to 2.7) was found in athletes.

Conclusion

Athletes had a 50% higher prevalence of ER and a 30% higher prevalence of ER in the inferior leads specifically. There was no association between training duration or sports discipline and ER.

Different habitus but similar electrocardiogram: Cardiac repolarization parameters in children - Comparison of elite athletes to obese children

Introduction:

The standard 12-lead electrocardiogram (ECG) remains a widely used tool in the basic cardiac evaluation of children and adolescents. With the emergence of inherited arrhythmia syndromes, the period of cardiac repolarization has been the focus of attention. So far, data on cardiac repolarization and its normal variants in healthy children are scarce. This may cause uncertainties in the differentiation between pathologies and normal variants. As abnormal autonomic regulation seems to be a major influencing factor on cardiac repolarization, this study aimed to evaluate the parameters of cardiac repolarization of children in extremely good physical shape to obese children to improve knowledge about cardiac repolarization in these subgroups of pediatric patients that are vastly affected by the alterations of autonomic regulation.

Methods:

A total of 426 pediatric volunteers (84 lean, healthy controls; 130 obese healthy pediatric volunteers; and 212 elite athletes) were enrolled in the study, and the parameters of cardiac repolarization were determined in 12-lead ECG.

Results:

Most importantly, there were no pathological findings, neither in the healthy controls nor in the obese or athletes. Athletes showed overall shorter corrected QT intervals than children from the other groups. This is also true if a correction of the QT interval is performed using the Hodges formula to avoid bias due to a tendency to lower heart rates in athletes. Athletes showed the shortest Tpeak-to-end ratios between the groups. The comparison of athletes from primarily strength and power sports versus those from endurance sports showed endurance-trained athletes to have significantly longer QT intervals.

Conclusions:

This study suggests that neither obesity nor extensive sports seems to result in pathological cardiac repolarization parameters in healthy children. Therefore, pathology has to be assumed if abnormal repolarization parameters are seen and might not be simply attributed to the child's habitus or an excellent level of fitness.

Performance and cardiac evaluation before and after a 3-week training camp for 400-meter sprinters - An observational, non-randomized study

Objective

To study the performance and cardiovascular function after a 3-week training camp in athletes competing in an anaerobically dominant sport.

Methods

Twenty-three competitive 400-m athletes were enrolled in this non-randomized study, 17 took part in a 3-week training camp in South-Africa (intervention), but one declined follow-up assessment, while 6 pursued in-door winter training in Sweden and served as controls. Electrocardiography, transthoracic echocardiography, blood test analyses, maximal exercise tolerance test, and a 300-m sprint test with lactate measurements ([La]peak) were performed before and after the training camp period.

Results

At baseline, there were no clinically significant pathological findings in any measurements. The training period resulted in improved 300m-sprint performance [n = 16; running time 36.71 (1.39) vs. 35.98 (1.13) s; p<0.01] and higher peak lactate values. Despite 48% more training sessions than performed on home ground (n = 6), myocardial biomarkers decreased significantly (NT-pro BNP -38%; p<0.05, troponin T -16%; p<0.05). Furthermore, resting heart rate (-7%; p<0.01) and left ventricular systolic and diastolic volumes decreased -6% (p<0.01) and -10% (p<0.05), respectively.

Conclusions

Intense physical activity at training camp improved the performance level, likely due to improved anaerobic capacity indicated by higher [La]peak. There were no clinically significant adverse cardiac changes after this period of predominantly anaerobic training.

The early repolarization pattern: Echocardiographic characteristics in elite athletes

BACKGROUND

The electrocardiographic early repolarization (ER) pattern is associated with idiopathic ventricular fibrillation and increased long-term cardiovascular mortality. Whether structural cardiac aberrations influence the phenotype is unclear. Since ER is particularly common in athletes, we evaluated its prevalence and investigated predisposing echocardiographic characteristics and cardiopulmonary exercise capacity in a cohort of elite athletes.

METHODS

A total of 623 elite athletes (age 21 ± 5 years) were examined during annual preparticipation screening from 2006 until 2012 including electrocardiography, echocardiography, and exercise testing. ECGs were analyzed with focus on ER. All athletes participated in a clinical follow-up.

RESULTS

The prevalence of ER was 17% (108/623). ER-positive athletes were predominantly male (71%, 77/108), showed a lower heart rate (57.1 ± 9.3 bpm versus 60.0 ± 11.2 bpm; p = 0.015) and a higher lean body mass compared to ER-negative participants (88.1% ± 5.6% versus 86.5% ± 6.3%; p = 0.015). Echocardiographic measurements and cardiopulmonary exercise capacity in male and female athletes with and without ER largely showed similar results. Only the notching ER subtype (n = 15) was associated with an increased left atrial diameter (OR 7.01, 95%CI 1.65-29.83; p = 0.008), a higher left ventricular mass (OR 1.02, 95%CI 1.00-1.03; p = 0.038) and larger relative heart volume (OR 1.01, 95%CI 1.00-1.01; p = 0.01). During a follow-up of 7.4 ± 1.5 years, no severe cardiovascular event occurred in the study sample.

CONCLUSIONS

In elite athletes presence of ER is not associated with distinct alterations in echocardiography and cardiopulmonary exercise. Athletes presenting with ER are rather male, lean with a low heart rate.

Seven years follow-up of early repolarisation patterns in French elite special forces

BACKGROUND

The early repolarization pattern (ERP) may be a marker of increased risk for sudden cardiac death (SCD). Influence of ethnicity on the ERP has not been extensively studied. The aim of this study was to evaluate the epidemiology of ERP in a male multiethnic population.

METHODS

ECG analysis was performed among consecutive recruits from the French Foreign Legion. ERP was characterized by a J-point elevation ≥0.1 mV in two continuous inferior-lateral leads, and high amplitude early repolarization (HAER-potentially malignant pattern) by an elevation ≥0.2 mV. Ethnical affiliation and level of physical activity were recorded.

RESULTS

A total of 2508 healthy men (24 ± 5 years old) from 105 different native countries were divided into three ethnic groups: 1689 Whites, 388 Afro-Caribbean, and 431 Asians. ERP was found in 489 recruits (19%), 14% in Whites, 33% in Afro-Caribbeans, and 27% in Asians without any difference according to age and physical activity. Sub-Saharan Africans or Caribbeans had the highest rate of ERP (30%), and Hispanics the lowest (8%). People from occidental countries, Middle East, Central Asia or India had a rate of 12%-18%, East and South-Asia 20%-25%. Madagascar was an exception with only 16% of ERP. HAER (2.9%) was more frequent among Asian recruits. After 5 ± 2 years of follow up, one SCD occurred in the ERP group (p = 0.042).

CONCLUSION

This study reports a large multiethnic analysis of ERP. HAER was more frequent in recruits from East and South-East Asia where sudden unexplained nocturnal death syndrome is endemic.

The prevalence of electrocardiogram abnormalities in professional divers

BACKGROUND

The underwater environment presents physiological challenges for the cardiovascular, renal and pulmonary systems. Increases in external hydrostatic pressure reduce the capacity of the venous compartment and cause blood to move toward the lung. The aim of this study was to evaluate retrospectively electrocardiographic (ECG) changes in a cohort of professional divers.

METHODS

Between January 2009 and January 2012, 225 randomly selected professional divers, 204 male (91%) and 21 female (9%) attended our clinic for their biannual diving medical assessment. Their ECG records were evaluated retrospectively.

RESULTS

The most common ECG abnormality observed was incomplete right bundle branch block (IRBBB) in 30 divers (13.3%). Eleven divers (4.9%) showed right QRS axis deviation (seven with IRBBB). Six divers had a sinus tachycardia; in four divers there was early repolarization; three divers had ventricular extrasystoles; one diver had ST elevation in lead V3; there was one with sinus arrhythmia and another with T-wave inversion in leads V2, V3 and aVF. These ECG changes were evaluated retrospectively by a cardiologist who made various recommendations for further review including bubble contrast echocardiography for IRBBB.

CONCLUSIONS

No serious ECG abnormalities were identified, but IRBBB should be further investigated because of its association with persistent (patent) foramen ovale. Rapid cardiological review of ECGs could be achieved using modern communications technology, such as telecardiography, and further clinical investigations directed by specialist recommendation arranged promptly if indicated.

Early repolarization syndrome: A cause of sudden cardiac death

Early repolarization syndrome (ERS), demonstrated as J-point elevation on an electrocardiograph, was formerly thought to be a benign entity, but the recent studies have demonstrated that it can be linked to a considerable risk of life - threatening arrhythmias and sudden cardiac death (SCD). Early repolarization characteristics associated with SCD include high - amplitude J-point elevation, horizontal and/or downslopping ST segments, and inferior and/or lateral leads location. The prevalence of ERS varies between 3% and 24%, depending on age, sex and J-point elevation (0.05 mV vs 0.1 mV) being the main determinants. ERS patients are sporadic and they are at a higher risk of having recurrent cardiac events. Implantable cardioverter-defibrillator implantation and isoproterenol are the suggested therapies in this set of patients. On the other hand, asymptomatic patients with ERS are common and have a better prognosis. The risk stratification in asymptomatic patients with ERS still remains a grey area. This review provides an outline of the up-to-date evidence associated with ERS and the risk of life - threatening arrhythmias. Further prospective studies are required to elucidate the mechanisms of ventricular arrhythmogenesis in patients with ERS.