Athlete's Heart and ECG
Last update: May 2020
Cardiovascular causes of sudden death in young competitive athletes in the United States
  Most common: Hypertrophic cardiomyopathy, Congenital coronary artery anomaly
  Less common: Myocarditis, Aortic rupture (Marfan syndrome), Mitral valve prolapse.
  Uncommon: Arrhythmogenic RV cardiomyopathy, Atherosclerotic coronary artery disease,
Conduction system abnormalities, Aortic valve stenosis
The following ECG abnormalities may be observed in well-trained athletes and are not generally regarded as abnormal
  Sinus bradycardia.
- Normally heart rate should increase during exercise in athletes (as in normal healthy population).
- In athletes, sinus bradycardia generally does not result in syncope or dizziness.
- In athletes, no further investigation is needed unless heart rate decreases below 30/minute at rest.
- The sinus bradycardia at rest may diasappear after cessation of professional athletic training .
  Sinus arrhythmia. No need for further investigation unless there is a pause > 3 seconds while the patient is awake (during daytime).
  Early repolarization (in 50% of the athletes)
  Black athlete early repolarization variant: J-point elevation and convex (‘domed’) ST-segment elevation followed by T-wave inversion in leads V1-V4
in black athletes.
  Ectopic atrial rhythm
  Junctional rhythm
  Increased QRS voltage for left ventricular hypertrophy or right ventricular hypertrophy
  First-degree atrioventricular (AV) block (35%). Generally disappears during exercise (If PR interval ≥ 400 ms, this is abnormal and needs further investigation).
  2nd degree, type 1 (Wenkebach) atrioventricular (AV) block (10%). Generally disappears during exercise .
  Incomplete right bundle branch block (35%) ( may disappear after the cessation of professional athletic training ).
  Persistent juvenile T pattern (negative T waves in leads V1 to V3)
The following ECG abnormalities are borderline. Further investigation is needed if ≥ 2 of them are observed in an athlete:
  Left atrial abnormality
  Right atrial abnormality
  Left axis deviation (-30° to -90°)
  Right axis deviation (>120°)
  Complete right bundle branch block: rSR' pattern in lead V1 and a S wave wider than R wave in lead V6 with QRS duration ≥ 120 ms
The following ECG abnormalities are not related to sports. When observed in an athlete's ECG, they call for further investigation:
  T wave negativity other than juvenile T wave pattern (≥ 1 mm in depth in two or more contiguous leads; excludes leads aVR, III, and V1):
- Negative T waves in lateral or inferior leads is usually abnormal.
- Deep T wave negativity in any lead.
  ST segment depression ≥ 0.5 mm in depth in two or more contiguous leads.
  Left atrial abnormality
  Pathologic Q waves: Q/R ratio ≥ 0.25 or ≥ 40 ms in duration in two or more leads (excluding III and aVR).
  QRS ≥ 140 ms duration
  Epsilon wave
  Profound sinus bradycardia ( < 30 beat/minute)
  PR interval ≥ 400 ms
  Atrial tachyarrhythmias (supraventricular tachycardia, atrial fibrillation, atrial flutter)
  Ventricular arrhythmias (including 2 or more VPCs per 10 s tracing)
  Complete AV block
  Mobitz type II, 2nd degree AV block: Intermittently non-conducted P waves with a fixed PR interval.
  Complete left bundle branch block: QRS ≥ 120 ms, predominantly negative QRS complex in lead V1 (QS or rS), and upright notched or slurred
R wave in leads I and V6
  Preexcitation pattern
  Prolonged QT interval: QTc ≥ 470 ms (male), QTc ≥ 480 ms (female), QTc ≥ 500 ms (marked QT prolongation)
  Short QT interval
  Brugada Type 1 pattern
References
  J Am Coll Cardiol 2017;69:1057-1075. (International Recommendations for Electrocardiographic Interpretation in Athletes.) (free full-text)
  Eur Heart J 2009;30:1728-1735.
  Eur Heart J 2010;31,243-259.
  European Heart Journal 2005;26:516-524. (ESC Report Cardiovascular pre-participation screening of young competitive athletes for prevention of
sudden death: proposal for a common European protocol) (free full-text)
ECG 1. The ECG above belongs to a 38 years-old professional football player.
His ECHOcardiography and treadmill exercise tests were normal.
Sinus bradycardia is seen. He does not take any heart rate slowing medication.
Click here for a more detailed ECG