ECG in Athletes

Athlete ECGs: How to Interpret and Know When and How to Investigate Further

Dr. Sanjay Sharma, co-senior author of the International Recommendations for ECG Interpretation in Athletes, reviewed his approach to the Athlete's ECG. The following are key points from his talk:

1.            Increased vagal tone (e.g., sinus bradycardia, first degree atrioventricular block [AVB]) and increased chamber size due to physiologic remodeling (e.g., left ventricular hypertrophy [LVH], bi-atrial enlargement) account for normal ECG patterns seen in highly trained athletes.

2.            Isolated Sokolow-Lyon voltage criterion for LVH is common in male athletes and does not warrant further investigation. Sinus bradycardia <40 bpm, Mobitz type 1 second degree AVB and junctional rhythm are not uncommon and don't warrant further investigation in asymptomatic athletes.

3.            The early repolarization pattern accompanied by concave ST segment elevation is seen in 25-40% of highly trained athletes; more common among males, black athletes and those with voltage criteria for LVH; usually seen in leads V5 and V6.

4.            The juvenile ECG pattern (T-wave inversion in leads V1-V3) is acceptable up to age 16 years. T-wave inversions beyond V2 after age 16 warrants further assessment in Caucasian athletes.

5.            T-wave inversions in leads V1-V4 are present in 12% of black athletes and are usually preceded by J-point elevation and convex ST segment elevation. These ECG changes, including T-wave inversions, can often return to normal with detraining (see below ECGs); outside the context of age <16 years and black ethnicity, T wave inversions beyond V2 should be investigated. Look for other features of arrhythmogenic cardiomyopathy if the preceding J-point is not elevated.

6.            T wave inversions in contiguous inferior leads or lateral leads warrant investigation in all athletes.

7.            T wave inversions preceded by ST-segment depressions are suggestive of underlying pathology; ST segment depressions should always be considered abnormal; upright T wave in aVR in the context of T wave inversion in V5/V6 is suggestive of pathology involving the left ventricular apex.

8.            A pathological Q-wave (depth exceeding 25% of the height of proceeding R wave) is abnormal. This rule does not apply to aVL.

9.            The presence of left axis deviation, right axis deviation, voltage criterion for left atrial enlargement, voltage criterion for right atrial enlargement or voltage criterion for right ventricular hypertrophy in isolation or with other Group 1 changes (e.g., sinus bradycardia, first degree AVB, incomplete right bundle branch block [RBBB], early repolarization, isolated QRS voltage criteria for LVH) does not warrant investigation in asymptomatic athletes with a normal physical examination.

10.          Left bundle branch block always warrants investigation. RBBB is considered a borderline criterion. In an asymptomatic athlete, RBBB in isolation with QRS duration <140msec and in the absence of significant repolarization abnormalities does not warrant further investigation.

11.          A QTc ≥500 msec is suggestive of long QT syndrome. A QTc >470 msec in males or >480 msec in females is abnormal especially if there is T-wave notching or paradoxical prolongation of the QT interval with exercise. Diagnosis of long QT syndrome in an athlete with a QT interval 460–490 msec should be considered in the presence of at least one of the following: unheralded syncope, torsades de pointes, identification of a long QTc in first degree relative, family history of sudden unexplained death, notched T waves or paradoxical QT prolongation with exercise.

12.          Type 1 Brugada ECG pattern (coved type) is abnormal. Type 2 Brugada ECG pattern (saddle back) is non-specific. If a Type 2 pattern is seen, the ECG needs to repeated to ensure proper lead placement, and a repeat ECG with V1 and V2 in higher intercostal leads should be performed: if there is no evidence of a Type 1 Brugada pattern, no further assessment is required unless there is a history of syncope or relevant family history.

References 

Thank you to the FITs for all their hard work. We hope you enjoy the summaries.

Eugene H Chung, MD, FACC

Editorial Team Lead, Sports & Exercise Cardiology Clinical Topic Collection

https://www.acc.org/latest-in-cardiology/articles/2019/07/17/07/03/athlete-ecgs