Clinical Significance of Abnormal Electrocardiographic Patterns in Trained Athletes

Abstract

Background-The prevalence, clinical significance, and determinants of abnormal ECG patterns in trained athletes remain largely unresolved. Methods and Results-We compared ECG patterns with cardiac morphology (as assessed by echocardiography) in 1005 consecutive athletes (aged 24Ϯ6 years; 75% male) who were participating in 38 sporting disciplines. ECG patterns were distinctly abnormal in 145 athletes (14%), mildly abnormal in 257 (26%), and normal or with minor alterations in 603 (60%). Structural cardiovascular abnormalities were identified in only 53 athletes (5%). Larger cardiac dimensions were associated with abnormal ECG patterns: left ventricular end-diastolic cavity dimensions were 56.0Ϯ5.6, 55.4Ϯ5.7, and 53.7Ϯ5.7 mm (PϽ0.001) and maximum wall thicknesses were 10.1Ϯ1.4, 9.8Ϯ1.3, and 9.3Ϯ1.4 mm (PϽ0.001) in distinctly abnormal, mildly abnormal, and normal ECGs, respectively. Abnormal ECGs were also most associated with male sex, younger age (Ͻ20 years), and endurance sports (cycling, rowing/canoeing, and cross-country skiing). A subset of athletes (5% of the 1005) showed particularly abnormal or bizarre ECG patterns, but no evidence of structural cardiovascular abnormalities or an increase in cardiac dimensions. Conclusions-Most athletes (60%) in this large cohort had ECGs that were completely normal or showed only minor alterations. A variety of abnormal ECG patterns occurred in 40%; this was usually indicative of physiological cardiac remodeling. A small but important subgroup of athletes without cardiac morphological changes showed striking ECG abnormalities that suggested cardiovascular disease; however, these changes were likely an innocent consequence of long-term, intense athletic training and, therefore, another component of athlete heart syndrome. Such false-positive ECGs represent a potential limitation to routine ECG testing as part of preparticipation screening. (Circulation. 2000;102:278-284.)

Electrocardiograms of Collegiate Football Athletes

“…13 The abnormal frequency we noted is also considerably higher than the 45% prevalence reported in a large sample of athletes in various sports that did not include American football players. 7 Since our data are descriptive, we cannot confirm that our abnormal ECG findings are caused by football participation, nor can we predict that sport termination would resolve them. However, the magnitude of the abnormal frequency (79%), coupled with the results of other studies in athletes, 2,4,7 supports the speculation that football participation is a contributing causal factor.…”

“…7 Since our data are descriptive, we cannot confirm that our abnormal ECG findings are caused by football participation, nor can we predict that sport termination would resolve them. However, the magnitude of the abnormal frequency (79%), coupled with the results of other studies in athletes, 2,4,7 supports the speculation that football participation is a contributing causal factor. Others have reported that the cardiac changes in athletes that accompany training are generally benign and are reversible when training ceases.…”

“…2 The surface ECG reflects changes in cardiac morphology, and physically trained men and women often exhibit ECG patterns that would be considered abnormal in the untrained. 4,7 Defining the limits of ECG changes in healthy athletes engaged in various sports provides clinicians with criteria essential for an accurate diagnosis of health and disease.…”

“…The ECG changes reflect the cardiac remodeling that accompanies physical training. 4,7 Thus, cardiac adaptations and related ECG changes are expected as a consequence of sport-specific training by American football athletes.…”

“…More men than women athletes exhibit ECG abnormalities, and data are limited for African-American athletes. 4,7 Most sport-related ECG research has been conducted on endurance athletes, and rarely have American football athletes been studied. American football players were not included in a recent review on cardiac adaptations in athletes.…”