March 23, 2015
August 5, 2015


Electrocardiogram Screening in Athletes: Athletes who collapse secondary to cardiac causes:  typically do so suddenly, may demonstrate seizure activity secondary to ventricular tachycardia, and may have shockable rhythms (either ventricular tachycardia or ventricular fibrillation) when an AED is attached.

These are conditions you want to look for on ECG especially if history of sudden syncope (no prodrome of weak, dizzy, diaphoretic).

See below or attached PDF for clearer images (Electrocardiogram Screening in Athletes)

Also See Sport Medicine ECG quiz (Sports Medicine Quiz)

  1. Brugada
  2. HOCM
  3. Prolonged QT syndrome
  4. Wolf Parkinson White
  5. ARVD
  6. Short QT syndrome

ECG findings in keeping with potential Sudden Cardiac Death:

  1. Brugada Syndrome – It is due to a genetic mutation of cardiac sodium channel.

ECG: ST elevation > 2mm in in V1-3 followed by a negative twave ….  athletes with brugada syndrome may require an implantable cardioverter defribillator (ICD).
Figure 1 – ST elevation in V1 and V1 with downslope (


Figure 2 – Close-up of downsloping ST elevation in V1


Figure 3 – ECG with Brugada ST changes in V1, V2


  1. Hypertrophic obstructive cardiomyopathy (HOCM) – Hypertrophy of the cardiac myocardium potentially causing obstruction of outflow (N.B. association with WPW)


  1. Voltage criteria for Left ventricular Hypertrophy
  2. Deep narrow “dagger-like” Q waves in I, aVL, V5,6 and/or II, III, aVF
  3. Other ( Axis deviation, atrial enlargement, ST-T wave abnormalities)
    Figure 4 – Hypertrophic changes on EGG (Medscape via BJSM)



  1. Prolonged QT – Long QT syndrome or could be secondary to medications (TCAs, SSRI’s, antibiotics).

ECG: a simple way of estimating whether prolonged QT is long is comparing the QT to the RR interval.  If QT is more than half the distance of RR – you have a prolonged QT.

Figure 5- Prolonged QT syndrome close up of lead II


Figure 6 – Prolonged QT syndrome 12-lead ECG


 4.  Wolff-Parkinson White (WPW) – It is an accessory pathway that allows preexcitation.

ECG:  Delta wave – Delta waves are seen as a slow sloped beginning to an R wave. WPW is also associated with a shortened PR interval (<120).
Figure 7- Delta wave (


Figure 8 – shortened PR wave and delta waves


5.  Arrhythmogenic Right Ventricular Dysplasia (ARVD) – also known as arrhtymogenic right ventricular cardiomyopathy. Can lead to PVC’s and Ventricular tachycardia.

ECG: Epislon wave – wave occurs after QRS complex, and is a sign of ARVD
Figure 9 – ECG: Epislon wave – wave occurs after QRS complex, and is a sign of ARVD


Figure 10 – epsilon waves after QRS interval:


6.  Short QT syndrome – Characterized by a shortened QT length. Although there is no consensus on a single QT interval for diagnsosis, a QTc of <330 ms should be diagnostic for males and a QTc of < 340 ms in females.  It can lead to atrial fibrillation, ventricular tachycardia, ventricular fibrillation and sudden cardiac death.

Figure 11 ECG with short qt syndrome:


Dr. Neil Dilworth (2015/11/5 updated Oct 30, 2017)