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
