ECGs - Take The Test

In the following cases you are given clinical details (Stem) and an ECG for analysis. You may be given additional information e.g X-rays or CT scans or blood test results.

Your task is to:

  • List the significant findings in each ECG
  • Provide the most likely or important diagnosis

This combined approach is a better way of testing your analysis ability than one based just on getting the correct diagnosis. Listing the significant findings is sometimes the only option when faced with a complex or unfamiliar ECG tracing.

Example Case

Stem: Sixty year old woman with epigastric discomfort

+ ECG Analysis

  • The rhythm is regular
  • The ventricular rate is 60 beats per minute
  • The atrial rate is about 94 beats per minute
  • Complete heart block is present (2)
  • A junctional escape rhythm is present (3)
  • There is marked ST segment elevation and tall T waves in Leads II, III and aVF - the patient has a inferior STEMI
  • There is marked ST segment depression and T inversion in Leads 1 and aVL
  • Other ST-T changes are
    • Concave ST elevation in Leads V1 and V2
    • J point depression and a biphasic T wave in Lead V3
    • J point elevation and slight elevation of the ST segments in Leads V5 and V6.

Notes

While not part of the answer, assessing the QRS width, intervals, axis and transition zone is a good starting point for analysis:

  • The QRS width and the QT interval are normal
  • The frontal plane QRS axis is normal
  • The transition zone is in Lead V3

P waves are visible, but there is no relationship between the P waves and the QRS complexes in the rhythm strip. Comparing the ventricular rate and the atrial rate allow us to use the correct terminology for this situation:

  • AV dissociation is present if the ventricular rate (VR) is the same or faster the atrial rate (AR) i.e. VR ≥ AR. An example of this is ventricular tachycardia where there is a very rapid ventricular rate (e.g. 180 beats per minute) and simultaneously a slower atrial rate (e.g. 80 beats per minute). The faster ventricular rate causes a "functional" AV block that isolates (or dissociates) the atrial impulses from the impulses in the ventricles (except for occasional "capture" or "fusion beats").
  • Complete heart block is present if the ventricular rate (VR) is the less than the atrial rate (AR) i.e. VR < AR

The normal width of the QRS complexes means that the ventricular pacemaker is located near the AV node - the shorthand term for this is a junctional [escape] rhythm. The normal rate of a junctional (AV) rhythm is between 40-60 beats per minute - junctional rhythms with a rate faster than 60 beats per minute are called a "accelerated junctional rhythm".

Ok..now on to the cases...