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.
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.
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...