Electrocardiographic observations in professional football players

ECG findings in professional rugby players using international screening recommendations

Background

While World Rugby guidelines do not mandate the inclusion of an electrocardiogram (ECG) for all players, this is required for entry into international rugby competitions. We, therefore, sought to describe sport-specific normative ECG values and evaluate the performance of contemporary athlete ECG guidelines in male and female professional rugby players.

Methods

We retrospectively analysed professional rugby players' ECGs (n=356, male 79%) obtained during preparticipation screening (2010-2022), comparing by sex and playing position (forwards vs backs). ECGs were categorised as normal 'training-related', borderline and abnormal findings, as defined by the 2017 International Recommendations.

Results

84% of players had one or more normal, 'training-related' findings, with males having a higher prevalence than females (91% vs 60%, p<0.001). Most ECG findings did not vary by position. No female player had borderline or abnormal ECG findings. Borderline findings were present in 3% (n=12/356) of players. Abnormal findings were present in 2% (n=7/356) of players. Overall, 2.2% of ECGs were 'positive' (n=8/356, including n=1 ECG with two borderline findings).

Conclusions

The application of contemporary ECG interpretation criteria resulted in a low positivity rate isolated to male players. These results help inform the logistic feasibility of ECG-inclusive screening, which is already required to enter major tournaments.

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.

Electrocardiographic characteristics of trained and untrained standardbred racehorses

Background

Long‐term exercise induces cardiac remodeling that potentially influences the electrical properties of the heart.

Hypothesis/objectives

We assessed whether training alters cardiac conduction in Standardbred racehorses.

Animals

Two hundred one trained and 52 untrained Standardbred horses.

Methods

Cross‐sectional study. Resting ECG recordings were analyzed to assess heart rate (HR) along with standard ECG parameters and for identification of atrial and ventricular arrhythmias. An electrophysiological study was performed in 13 horses assessing the effect of training on sinoatrial (SA) and atrioventricular (AV) nodal function by sinus node recovery time (SNRT) and His signal recordings. Age and sex adjustments were implemented in multiple and logistic regression models for comparison.

Results

Resting HR in beats per minute (bpm) was lower in trained vs untrained horses (mean, 30.8 ± 2.6 bpm vs 32.9 ± 4.2 bpm; P = .001). Trained horses more often displayed second‐degree atrioventricular block (2AVB; odds ratio, 2.59; P = .04). No difference in SNRT was found between groups (n = 13). Mean P‐A, A‐H, and H‐V intervals were 71 ± 20, 209 ± 41, and 134 ± 41 ms, respectively (n = 7). We did not detect a training effect on AV‐nodal conduction intervals. His signals were present in 1 horse during 2AVB with varying H‐V interval preceding a blocked beat.

Conclusions and Clinical Importance

We identified decreased HR and increased frequency of 2AVB in trained horses. In 5 of 7 horses, His signal recordings had variable H‐V intervals within each individual horse, providing novel insight into AV conduction in horses.

Electrocardiographic and Echocardiographic Findings in Black Athletes: A General Review

BACKGROUND

Participation in regular physical activity produces electrophysiological and structural cardiac changes in electrocardiograms (ECGs) and echocardiographs (ECHOs) of athletes, and the term "athlete's heart" is used to describe these physiological cardiovascular adaptations. Extent and type of sporting discipline, age, sex, body dimensions, and ethnicity have an influence on cardiac remodeling.

OBJECTIVE

As the recent scientific literature increasingly reports on ethnicity-specific ECG and ECHO findings in black athletes, it is the aim of this review to provide an overview of ECG and ECHO findings among athletes of black African/Afro-Caribbean descent.

DATA SOURCES

A systematic search of PubMed and MEDLINE databases up to and including August 2017 was conducted using the following terms/phrases "black OR African OR Afro-Caribbean athlete heart," "black OR African OR Afro-Caribbean athlete electrocardiogram," and "black OR African OR Afro-Caribbean athlete echocardiogram." The search generated a total of 130 papers, out of which 16 original articles fitted our criteria and were selected for this review.

MAIN RESULTS

The various studies reviewed revealed that about 10% to 30% of black African/Afro-Caribbean athletes had abnormal ECG. R/S voltage criteria exceeding hypertrophic indices were found in about 60% to 89% of black African/Afro-Caribbean athletes. ST-segment elevation (17%-90%) and T-wave inversions were also common findings among this ethnicity. About 10% to 12% of black African/Afro-Caribbean athletes had a left ventricular wall thickness ranging from 13 to 15 mm. Cavity dimensions ranged from 40 to 66 mm in black African/Afro-Caribbean athletes with a relative wall thickness >0.44.

CONCLUSIONS

Updated ethnic-specific guidelines are required to discriminate physiological from pathologic hypertrophy and repolarization changes. Future studies should focus on homogeneous cohorts of African athletes.

Cardiac Structure and Function in Elite Female and Male Soccer Players

Importance

Population-specific normative data are essential for the evaluation of competitive athletes. At present, there are limited data defining normal electrocardiographic (ECG) and echocardiographic values among elite US soccer players.

Objective

To describe ECG and echocardiographic findings in healthy elite US soccer players.

Design, Setting, and Participants

This cross-sectional study analyzed Fédération Internationale de Football Association-mandated screening sessions performed at US Soccer National Team training locations from January 2015 to December 2019. US women's and men's national team soccer players undergoing mandated cardiovascular screening were included.

Main Outcomes and Measures

Normal training-related and abnormal ECG findings were reported using the International Recommendations for Electrocardiographic Interpretation in Athletes. Echocardiographic measurements of structural and functional parameters relevant to cardiovascular remodeling were assessed relative to American Society of Echocardiography guideline-defined normal ranges.

Results

A total of 238 athletes (122 [51%] female; mean [SD] age, 20 [4] years; age range, 15-40 years) were included. Male athletes demonstrated a higher prevalence of normal training-related ECG findings, while female athletes were more likely to have abnormal ECG patterns (14 [11%] vs 0 in male cohort), largely accounted for by abnormal T-wave inversions. Echocardiography revealed no pathologic findings meeting criteria for sport restriction, but athletes frequently exceeded normal ranges for structural cardiac parameters responsive to exercise-induced remodeling including body surface area-indexed left ventricular (LV) mass (58 of 113 female athletes [51%] and 67 of 114 male athletes [59%]), indexed LV volume (89 of 115 female athletes [77%] and 76 of 111 male athletes [68%]), and LV wall thickness (37 of 122 female athletes [30%] and 47 of 116 male athletes [41%]). Age-stratified analysis revealed age-dependent increases in LV wall thickness, mass, and volumes among female athletes and LV wall thickness and mass among male athletes.

Conclusions and Relevance

These data represent the first set of comprehensive normative values for elite US soccer players and one of the largest sport-specific echocardiographic remodeling studies in female athletes. Abnormal ECG findings were more common in female athletes, while both female and male athletes frequently exceeded clinical normality cut points for remodeling-associated echocardiographic parameters.

Electrocardiographic Findings in National Basketball Association Athletes

Importance

While it is known that long-term intensive athletic training is associated with cardiac structural changes that can be reflected on surface electrocardiograms (ECGs), there is a paucity of sport-specific ECG data. This study seeks to clarify the applicability of existing athlete ECG interpretation criteria to elite basketball players, an athlete group shown to develop significant athletic cardiac remodeling.

Objective

To generate normative ECG data for National Basketball Association (NBA) athletes and to assess the accuracy of athlete ECG interpretation criteria in this population.

Design, Setting, and Participants

The NBA has partnered with Columbia University Medical Center to annually perform a review of policy-mandated annual preseason ECGs and stress echocardiograms for all players and predraft participants. This observational study includes the preseason ECG examinations of NBA athletes who participated in the 2013-2014 and 2014-2015 seasons, plus all participants in the 2014 and 2015 NBA predraft combines. Examinations were performed from July 2013 to May 2015. Data analysis was performed between December 2015 and March 2017.

Exposures

Active roster or draft status in the NBA and routine preseason ECGs and echocardiograms.

Main Outcomes and Measures

Baseline quantitative ECG variables were measured and ECG data qualitatively analyzed using 3 existing, athlete-specific interpretation criteria: Seattle (2012), refined (2014), and international (2017). Abnormal ECG findings were compared with matched echocardiographic data.

Results

Of 519 male athletes, 409 (78.8%) were African American, 96 (18.5%) were white, and the remaining 14 (2.7%) were of other races/ethnicities; 115 were predraft combine participants, and the remaining 404 were on active rosters of NBA teams. The mean (SD) age was 24.8 (4.3) years. Physiologic, training-related changes were present in 462 (89.0%) athletes in the study. Under Seattle criteria, 131 (25.2%) had abnormal findings, compared with 108 (20.8%) and 81 (15.6%) under refined and international criteria, respectively. Increased age and increased left ventricular relative wall thickness (RWT) on echocardiogram were highly associated with abnormal ECG classifications; 17 of 186 athletes (9.1%) in the youngest age group (age 18-22 years) had abnormal ECGs compared with 36 of the 159 athletes (22.6%) in the oldest age group (age 27-39 years) (odds ratio, 2.9; 95% CI, 1.6-5.4; P < .001). Abnormal T-wave inversions (TWI) were present in 32 athletes (6.2%), and this was associated with smaller left ventricular cavity size and increased RWT. One of the 172 athletes (0.6%) in the lowest RWT group (range, 0.24-0.35) had TWIs compared with 24 of the 163 athletes (14.7%) in the highest RWT group (range, 0.41-0.57) (odds ratio, 29.5; 95% CI, 3.9-221.0; P < .001).

Conclusions and Relevance

Despite the improved specificity of the international recommendations over previous athlete-specific ECG criteria, abnormal ECG classification rates remain high in NBA athletes. The development of left ventricular concentric remodeling appears to have a significant influence on the prevalence of abnormal ECG classification and repolarization abnormalities in this athlete group.

Higher Prevalence of Abnormal Electrocardigrams (ECG) in African Americans Undergoing Screening ECG and Echocardiography

BACKGROUND

African American (AA) has higher prevalence of abnormal electrocardigrams (ECG) in general population. However, the degree of these abnormalities in a healthy population undergoing screening echocardiography is not known. The goal of this study was to evaluate the prevalence of ECG abnormalities reported during screening echocardiography based on race.

METHOD

The Anthony Bates Foundation has been performing screening across the United States for the prevention of sudden death since 2001. We evaluated a total of 633 participants with documented race and ECG for the presence of any abnormalities.

RESULTS

The age of the study population ranged between 6 and 75 years old. The prevalence of abnormal ECG in AA participant was 20.7% (12/58) versus 6.6% (38/578) in other races [odds ratio (OR), 3.70; confidence interval (CI), 1.8-7.58; P < 0.001]. Using multivariate analysis adjusting for age, sex, body mass index, left ventricular hypertrophy, and hypertension (systolic blood pressure >140 and diastolic blood pressure of >90), AA race remained independently associated with abnormal ECG (OR, 2.58; CI, 1.12-5.97; P = 0.02). Limiting our study only to teenagers (age, 13-19 years), AA race remained significantly associated with higher prevalence of ECG abnormalities [23.1% (12/58) of teenage AA had abnormal ECG vs. 7.5% (24/321) of other teenage races; OR, 3.71; CI, 1.36-10.11; P = 0.006]. After excluding benign ECG abnormalities such as sinus bradycardia and early repolarization, AA race remained significantly associated with higher prevalence of abnormal ECG (16.7% vs. 7.3%; OR, 2.52; CI, 0.998-6.39; P = 0.054).

CONCLUSIONS

The prevalence of abnormal ECG is higher in AA race independent of echocardiographic abnormalities or demographics. However, some of these abnormalities appear to be related to sinus bradycardia and early repolarization.

"Persistent Juvenile" T-Wave Pattern May Not Be Persistent: Case Series and Literature Review

BACKGROUND

T-wave inversions (TWI) can signify serious pathology, but may also represent a benign variant. One such variant has been termed the "persistent juvenile" T-wave pattern (PJTWP). It is characterized by TWI in the right precordium, and has been understood to represent an arrested stage of the normal electrocardiographic evolution from childhood.

CASE REPORT

A series of four African-American (AA) women, ages 20 to 43 years, presented to the Emergency Department, and were found to have right precordial TWI that was absent on prior electrocardiograms. The diagnostic evaluation did not reveal acute cardiopulmonary causes for these new TWIs. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The "persistent" juvenile pattern may not be actually persistent in the individual patient. In an appropriate patient, such as a young AA woman, where acute cardiopulmonary disease has been reasonably ruled out, the finding of new right precordial TWI should not preclude the diagnosis of PJTWP.

T wave inversions in athletes: a variety of scenarios

Athletic intensive exercise is associated with repolarization changes affecting the ST-segment and T-wave morphology. The prevalence and distribution of these alterations are influenced by several demographic factors. One of the most challenging conundrums for both the cardiologist and the sports medicine physician is the correct interpretation of these repolarization changes to prevent an erroneous diagnosis with potentially serious consequences. A 12-lead electrocardiogram (ECG) demonstrating inverted T-waves may represent the first and only sign of such inherited heart muscle diseases, and may precede the detection of any structural changes in the heart, however, T-wave inversion in leads V1-V4 in black athletes may represent ethnic variation which is exaggerated by exercise.

Prevalence and significance of isolated T wave inversion in 1755 consecutive American collegiate athletes

BACKGROUND

We evaluated the prevalence of isolated T-wave inversions (TWI) in American athletes using contemporary ECG criteria. Ethnic and gender disparities including the association of isolated TWI with underlying abnormal cardiac structure are evaluated.

METHODS

From 2004 to 2014, 1755 collegiate athletes at a single American university underwent prospective collection of medical history, physical examination, 12-lead ECG, and 2-dimensional echocardiography. ECG analysis was performed to evaluate for isolated TWI as per contemporary ECG criteria.

RESULTS

The overall prevalence of isolated TWI is 1.3%. Ethnic and gender disparities are not observed in American athletes (black vs. white: 1.7% vs. 1.1%; p=0.41) (women vs. men: 1.5% vs. 1.1; p=0.52). No association was found with underlying cardiomyopathy.

CONCLUSION

A lower prevalence of isolated TWI in American athletes than previously reported. Isolated TWI was not associated with an abnormal echocardiogram. No ethnic or gender disparity is seen in American college athletes.

Sports reporting: a comprehensive review of the medical literature regarding North American professional sports

BACKGROUND

The increased physical demands of professional athletes predispose this patient population to a unique set of injuries typically not seen in the general population. This systematic literature review investigates the nature of injury reporting (both orthopedic and nonorthopedic conditions) in the medical literature of professional athletes in the National Football League (NFL), Major League Baseball (MLB), the National Basketball Association (NBA), and the National Hockey League (NHL). Rigorous reporting of sports injuries helps clinicians better understand disease mechanisms relevant to specific sports.

HYPOTHESIS

The nature of injury reporting will differ within each professional sport and reflect the anatomic emphasis of each sport.

METHODS

An electronic literature search of all publications addressing injuries and medical conditions among professional athletes in the NFL, MLB, NBA, and NHL was conducted using the Pubmed/Medline, Scopus, and Embase databases through January 2013. Retrieved publications were categorized by journal type, medical type, and area of focus.

RESULTS

A total of 536 publications met all inclusion criteria. There were a higher number of articles regarding the NFL (n = 211) and MLB (n = 216) when compared with the NBA (n = 34) or NHL (n = 75). The NFL had significantly more articles addressing nonorthopedic injuries/medical issues than were found with the MLB, NBA, or NHL (109 vs 75, 14, 41, respectively). Both the NFL (33 of 109, 30%) and NHL (6 of 41, 15%) had a relatively high percentage of articles regarding concussions/neurology, and MLB had a relatively high percentage of articles dedicated to vascular medicine (13 of 65, 20%). The proportion of publications dedicated to the knee/lower leg were highest in the NFL (29 of 102, 28%) and NBA (9 of 20, 45%), those dedicated to the shoulder/elbow were highest in MLB (113 of 151, 75%), and those dedicated to the hip/pelvis were highest in the NHL (16 of 34, 47%).

CONCLUSIONS

The number and type of publications vary among the 4 professional sports leagues, and generally reflect the nature of the sport being played.

Impact of ethnicity on cardiac adaptation to exercise

The increasing globalization of sport has resulted in athletes from a wide range of ethnicities emerging onto the world stage. Fuelled by the untimely death of a number of young professional athletes, data generated from the parallel increase in preparticipation cardiovascular evaluation has indicated that ethnicity has a substantial influence on cardiac adaptation to exercise. From this perspective, the group most intensively studied comprises athletes of African or Afro-Caribbean ethnicity (black athletes), an ever-increasing number of whom are competing at the highest levels of sport and who often exhibit profound electrical and structural cardiac changes in response to exercise. Data on other ethnic cohorts are emerging, but remain incomplete. This Review describes our current knowledge on the impact of ethnicity on cardiac adaptation to exercise, starting with white athletes in whom the physiological electrical and structural changes--collectively termed the 'athlete's heart'--were first described. Discussion of the differences in the cardiac changes between ethnicities, with a focus on black athletes, and of the challenges that these variations can produce for the evaluating physician is also provided. The impact of ethnically mediated changes on preparticipation cardiovascular evaluation is highlighted, particularly with respect to false positive results, and potential genetic mechanisms underlying racial differences in cardiac adaptation to exercise are described.

The asymptomatic teenager with an abnormal electrocardiogram

Use of medications for attention-deficit hyperkinetic disorder and preparticipation sports physical examination has led to an increase in number of electrocardiograms (ECG) performed during adolescence. Interpreting ECGs in children and young adults must take into account the evolutionary changes with age and the benign variants, which are usually not associated with heart disease. It is crucial for primary-care providers to recognize the changes on ECG associated with heart disease and risk of sudden death. In this article, the significance, sensitivity, specificity, and the diagnostic workup of these findings in the asymptomatic teenager are discussed.

March Madness 2011: for whom the bell tolls?

The American Heart Association has developed 12 recommendations for preparticipation screening of high school and college athletes, but the application of these recommendations across the US is inconsistent. A recent clinical study suggests that the incidence and prevalence of sudden athletic death (SAD) is greater than previously believed. Currently, diagnostic screening is considered too expensive and is delivered sporadically. Logic dictates that the medical community must become more involved in reducing the incidence and prevalence of SAD through an improved preparticipation screening process. An effective screening process must be able to reproducibly predict and prevent potential risk using the most effective resources and keeping the cost-benefit ratio at a minimum. The most effective use of our resources will limit the potential of liability for institutions and physicians and, hopefully, eliminate episodes of SAD.

Prevalence of electrocardiographic abnormalities in an unselected young male multi-ethnic South-East Asian population undergoing pre-participation cardiovascular screening: results of the Singapore Armed Forces Electrocardiogram and Echocardiogram screening protocol

AIMS

Resting 12-lead electrocardiograms (ECGs) have been employed in the pre-participation evaluation of young asymptomatic subjects to detect pre-existing heart diseases. Although the incorporation of routine ECG in pre-participation screening remains controversial, there is increasing evidence that cardiomyopathies and ion channelopathies have ECG changes as the initial manifestation. The causes of sudden cardiac death in young people show significant geographical variation. We aim to determine the prevalence and spectrum of ECG abnormalities in a young male South-East Asian population.

METHODS AND RESULTS

The Singapore Armed Forces Electrocardiogram and Echocardiogram (SAFE) protocol is an ECG-based pre-participation cardiac screening programme modelled after the Italian system. From October 2008 to May 2009, a total of 18 476 young male conscripts (mean age 19.5 years old, range 16-27) underwent mandatory pre-enlistment medical screening at a single medical facility. Subjects with abnormal ECG findings were classified into two groups: Group A had ECG changes that fulfilled a pre-specified checklist to screen for hypertrophic cardiomyopathy and were referred for transthoracic echocardiogram; Group B had other ECG abnormalities [such as Brugada pattern, Wolff-Parkinson-White (WPW) pattern, long QTc] and were referred for secondary screening at a tertiary institution. Of the 18 476 subjects screened, 7.0% (n= 1285) had ECG abnormalities. Of note, 19 (0.10%) had Brugada pattern, 25 (0.14%) had WPW pattern, and 31 (0.17%) had prolonged QT interval on ECG. The prevalence of ECG abnormalities was significantly higher in Chinese than in South Asians (7.2 vs. 5.7%, P= 0.003).

CONCLUSION

The prevalence of ECG abnormalities in a young, South-East Asian male population was 7.0%. There were significant ethnic differences, with ECG abnormalities more prevalent in Chinese than in South Asians (7.2 vs. 5.7%, P= 0.003). The inclusion of universal ECG, in addition to history and physical examination, may increase the sensitivity of a cardiovascular screening programme. Knowledge of the spectrum and prevalence of ECG abnormalities and disease conditions would be pivotal in designing customized screening programmes.

Cardiovascular screening with electrocardiography and echocardiography in collegiate athletes

BACKGROUND

Current guidelines for preparticipation screening of competitive athletes in the US include a comprehensive history and physical examination. The objective of this study was to determine the incremental value of electrocardiography and echocardiography added to a screening program consisting of history and physical examination in college athletes.

METHODS

Competitive collegiate athletes at a single university underwent prospective collection of medical history, physical examination, 12-lead electrocardiography, and 2-dimensional echocardiography. Electrocardiograms (ECGs) were classified as normal, mildly abnormal, or distinctly abnormal according to previously published criteria. Eligibility for competition was determined using criteria from the 36(th) Bethesda Conference on Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities.

RESULTS

In 964 consecutive athletes, ECGs were classified as abnormal in 334 (35%), of which 95 (10%) were distinctly abnormal. Distinct ECG abnormalities were more common in men than women (15% vs 6%, P<.001) as well as black compared with white athletes (18% vs 8%, P<.001). Echocardiographic and electrocardiographic findings initially resulted in exclusion of 9 athletes from competition, including 1 for long QT syndrome and 1 for aortic root dilatation; 7 athletes with Wolff-Parkinson-White patterns were ultimately cleared for participation. (Four received further evaluation and treatment, and 3 were determined to not need treatment.) After multivariable adjustment, black race was a statistically significant predictor of distinctly abnormal ECGs (relative risk 1.82, 95% confidence interval, 1.22-2.73; P=.01).

CONCLUSIONS

Distinctly abnormal ECGs were found in 10% of athletes and were most common in black men. Noninvasive screening using both electrocardiography and echocardiography resulted in identification of 9 athletes with important cardiovascular conditions, 2 of whom were excluded from competition. These findings offer a framework for performing preparticipation screening for competitive collegiate athletes.

The prevalence, distribution, and clinical outcomes of electrocardiographic repolarization patterns in male athletes of African/Afro-Caribbean origin

AIMS

Athletic training in male black athletes (BAs) is associated with marked ECG repolarization changes that overlap with hypertrophic cardiomyopathy (HCM). Differentiating between the two entities is prudent since BAs exhibit a higher prevalence of exercise-related sudden death from HCM compared with white athletes (WAs).

METHODS AND RESULTS

Between 1996 and 2010, 904 BAs underwent serial cardiac evaluations including ECG and echocardiography. Athletes exhibiting T-wave inversions were investigated further for HCM. Results were compared with 1819 WAs, 119 black controls (BCs), and 52 black HCM patients. Athletes were followed up for 69.7 ± 29.6 months. T-wave inversions were present in 82.7% HCM patients, 22.8% BAs, 10.1% BCs, and 3.7% WAs. In athletes, the major determinant of T-wave inversions was black ethnicity. T-wave inversions in BAs (12.7%) were predominantly confined to contiguous anterior leads (V1-V4). Only 4.1% of BAs exhibited T-wave inversions in the lateral leads. In contrast, both BCs and HCM patients exhibited lower prevalence of T-wave inversions in leads V1-V4 (4.2 and 3.8%, respectively) with most T-wave inversions in HCM patients (76.9%) involving the lateral leads. During follow-up one BA survived cardiac arrest and two athletes (one BA, one WA) were diagnosed with HCM. All three exhibited T-wave inversions in the lateral leads.

CONCLUSIONS

T-wave inversions in leads V1-V4 appear to represent an ethnic variant of 'athlete's heart'. Conversely, T-wave inversions in the lateral leads may represent the initial expression of underlying cardiomyopathy and merit further evaluation and regular surveillance.

Risk of sudden death among young individuals with J waves and early repolarization: putting the evidence into perspective

The presence of J waves and ST-segment elevation on the electrocardiogram (ECG), jointly termed "the early repolarization pattern," has traditionally been considered a marker of "good health." However, recent case control series and long-term population studies have established a statistically significant association between this ECG pattern and an increased risk for arrhythmic death. This finding has raised concern among physicians, who now are asked to estimate the "arrhythmic risk" following the incidental discovery of J waves on routine ECG. Therefore, we review the literature linking early repolarization with arrhythmic risk to place this "fear of J waves" in the right perspective. We found five case control studies (involving 331 patients with idiopathic ventricular fibrillation [VF] and 8,649 controls). All of these studies showed that J waves, particularly of large amplitude and recorded in multiple leads, are more prevalent among patients with idiopathic VF. We also found three large population studies (involving >17,000 individuals) looking at the prognostic value of early repolarization. Two of these studies showed that the presence of J waves >2 mm in amplitude in asymptomatic adults is associated with a threefold increased of arrhythmic death during very long-term follow-up. Individuals with J waves do have some degree of increased dispersion of repolarization that places them at increased risk for arrhythmic death, but only in the presence of additional proarrhythmic factors or triggers. A sensible approach for the asymptomatic patient with J waves is proposed.

Cardiovascular screening of adolescent athletes

A preparticipation cardiovascular screening is recommended for all athletes with the aim of identifying conditions that increase the risk for adverse cardiac event, including sudden death. History and physical examination are the mainstay of cardiovascular screening of young athletes. The ability to identify athletes at risk, however, based on history and physical examination alone is low, and inclusion of an electrocardiogram as a screening tool has been suggested to improve the sensitivity of screening. This article provides an overview of key aspects of cardiovascular screening currently recommended in the United States for young athletes.

Addition of the electrocardiogram to the preparticipation examination of college athletes

OBJECTIVE

Although the use of standardized cardiovascular (CV) system-focused history and physical examination is recommended for the preparticipation examination (PPE) of athletes, the addition of the electrocardiogram (ECG) has been controversial. Because the impact of ECG screening on college athletes has rarely been reported, we analyzed the findings of adding the ECG to the PPE of Stanford athletes.

DESIGN

For the past 15 years, the Stanford Sports Medicine program has mandated a PPE questionnaire and physical examination by Stanford physicians for participation in intercollegiate athletics. In 2007, computerized ECGs with digital measurements were recorded on athletes and entered into a database.

SETTING

Although the use of standardized CV-focused history and physical examination are recommended for the PPE of athletes, the addition of the ECG has been controversial. Because the feasibility and outcomes of ECG screening on college athletes have rarely been reported, we present findings derived from the addition of the ECG to the PPE of Stanford athletes. For the past 15 years, the Stanford Sports Medicine program has mandated a PPE questionnaire and physical examination by Stanford physicians for participation in intercollegiate athletics. In 2007, computerized ECGs with digital measurements were recorded on athletes and entered into a database.

MAIN OUTCOME MEASURES

Six hundred fifty-eight recordings were obtained (54% men, 10% African-American, mean age 20 years) representing 24 sports. Although 68% of the women had normal ECGs, only 38% of the men did so. Incomplete right bundle branch block (RBBB) (13%), right axis deviation (RAD) (10%), and atrial abnormalities (3%) were the 3 most common minor abnormalities. Sokolow-Lyon criteria for left ventricular hypertrophy (LVH) were found in 49%; however, only 27% had a Romhilt-Estes score of >or=4. T-wave inversion in V2 to V3 occurred in 7%, and only 5 men had abnormal Q-waves. Sixty-three athletes (10%) were judged to have distinctly abnormal ECG findings possibly associated with conditions including hypertrophic cardiomyopathy or arrhythmogenic right ventricular dysplasia/cardiomyopathy. These athletes were offered further testing but this was not mandated according to the research protocol.

RESULTS

Six hundred fifty-three recordings were obtained (54% men, 7% African American, mean age 20 years), representing 24 sports. Although 68% of the women had normal ECGs, only 38% of the men did so. Incomplete RBBB (13%), RAD (10%), and atrial abnormalities (3%) were the 3 most common minor abnormalities. Sokolow-Lyon criteria for LVH were found in 49%; however, only 27% had a Romhilt-Estes score of >or=4. T-wave inversion in V2 to V3 occurred in 7% and only 5 men had abnormal Q-waves. Sixty-five athletes (10%) were judged to have distinctly abnormal ECG findings suggestive of arrhythmogenic right ventricular dysplasia, hypertrophic cardiomyopathy, and/or biventricular hypertrophy. These athletes will be submitted to further testing.

CONCLUSIONS

Mass ECG screening is achievable within the collegiate setting by using volunteers when the appropriate equipment is available. However, the rate of secondary testing suggests the need for an evaluation of cost-effectiveness for mass screening and the development of new athlete-specific ECG interpretation algorithms.

Ethnic differences in physiological cardiac adaptation to intense physical exercise in highly trained female athletes

BACKGROUND

Ethnicity is an important determinant of cardiovascular adaptation in athletes. Studies in black male athletes reveal a higher prevalence of electric repolarization and left ventricular hypertrophy than observed in white males; these frequently overlap with those observed in cardiomyopathy and have important implications in the preparticipation cardiac screening era. There are no reports on cardiac adaptation in highly trained black females, who comprise an increasing population of elite competitors.

METHODS AND RESULTS

Between 2004 and 2009, 240 nationally ranked black female athletes (mean age 21+/-4.6 years old) underwent 12-lead ECG and 2-dimensional echocardiography. The results were compared with 200 white female athletes of similar age and size participating in similar sports. Black athletes demonstrated greater left ventricular wall thickness (9.2+/-1.2 versus 8.6+/-1.2 mm, P<0.001) and left ventricular mass (187.2+/-42 versus 172.3+/-42 g, P=0.008) than white athletes. Eight black athletes (3%) exhibited a left ventricular wall thickness >11 mm (12 to 13 mm) compared with none of the white athletes. All athletes revealed normal indices of systolic and diastolic function. Black athletes exhibited a higher prevalence of T-wave inversions (14% versus 2%, P<0.001) and ST-segment elevation (11% versus 1%, P<0.001) than white athletes. Deep T-wave inversions (-0.2 mV) were observed only in black athletes and were confined to the anterior leads (V(1) through V(3)).

CONCLUSIONS

Systematic physical exercise in black female athletes is associated with greater left ventricular hypertrophy and higher prevalence of repolarization changes than in white female athletes of similar age and size participating in identical sporting disciplines. However, a maximal left ventricular wall thickness >13 mm or deep T-wave inversions in the inferior and lateral leads are rare and warrant further investigation.

Adding an electrocardiogram to the pre-participation examination in competitive athletes: a systematic review

No matter how rare, the death of young athletes is a tragedy. Can it be prevented? The European experience suggests that adding the electrocardiogram (ECG) to the standard medical and family history and physical examination can decrease cardiac deaths by 90%. However, there has not been a randomized trial to demonstrate such a reduction. While there are obvious differences between the European and American experiences with athletes including very differing causes of athletic deaths, some would highlight the European emphasis on public welfare vs the protection of personal rights in the USA. Even the authors of this systematic review have differing interpretation of the data: some of us view screening as a hopeless battle against Bayes, while others feel that the ECG can save lives. What we all agree on is that the USA should implement the American Heart Association 12-point screening recommendations and that, before ECG screening is mandated, we need to gather more data and optimize ECG criteria for screening young athletes.

Electrocardiograms of collegiate football athletes

BACKGROUND

The prevalence of electrocardiogram (ECG) abnormalities in American collegiate football athletes is virtually unknown.

PURPOSE

The purpose of this study was to characterize the type and frequency of ECG abnormalities in a sample of football athletes entering National Collegiate Athletic Association (NCAA) Division I Football Bowl Subdivision university program.

METHODS

Over a 4-y period, resting and exercise 12-lead ECG recordings were analyzed by a cardiologist from 68 freshmen and 9 transfer football athletes (n=77; 54 African-Americans and 23 Caucasians, aged 18 +/- 1 y, height=1.89 +/- 0.06 m, weight= 104.4 +/- 19.8 kg) as part of their entry physical examination.

RESULTS

A total of 79% of the athletes demonstrated at least 1 abnormal ECG finnding, and significantly more African-America athletes (85%) than Caucasian (65%) athletes. Wolff-Parkinson-White (WPW) syndrome was found in 1 African-American player. Frequencies of various ECG abnormal findings in all athletes were: left ventricular hypertrophy = 64.5%, ST-T wave = 6.5%, interventricular conduction delay = 2.6%, sinus bradycardia = 9.1%, sinus arrhythmia = 15.6%, first-degree atrioventricular (AV) block = 11.7%, left atrial enlargement = 48.1%, early repolarization = 33.8%, and right axis deviation = 20.8%. Average values for the PR (0.17 +/- 0.03 s), QRS (0.08 +/- 0.02 s), and QT intervals (0.38 +/- 0.05 s), P-wave duration (0.10 +/- 0.02 s), and QRS axis (79.1 +/- 18.2 degrees) were normal. The ECG responses to maximal treadmill exercise stress tests were evaluated as normal without ischemia or arrhythmias.

CONCLUSION

Abnormal resting ECG findings are common in a sample of collegiate football athletes, exceeding the rate expected for their age, and are more frequent in African-American athletes as compared with Caucasian athletes.