What does this ECG show? Try it before you go on. screen-shot-2011-10-24-at-94337-pm

From ‘theecglibrary.com’

Let’s use the ‘ECG in 20 Seconds’ approach.

Step one: this is most likely an ischaemia or a PE given the history.

Rate = 25 (complexes across the whole ECG) x 6 = 150bpm

Rhythm = P waves are seen (best in lead II) – sinus. If unsure in the clinical picture, just look at the rate and see if it alters.

QRS = Widened QRS with RBBB

ST segments = There is T wave inversion in leads V1, V2 and III

Intervals = PR and QT intervals look OK

 

So this is a sinus rhythm ECG at 150 bpm, with a RBBB and T inversions in V1-2 and III.

If we are thinking of ischaemia, that’s fine, but I would be concerned about a Pulmonary Embolism.

We certainly can see the S1Q3T3 pattern. This only occurs in about 13% of cases.

There is also sinus tachycardia and a RBBB.

What I see is this pattern of T inversion in V1 and III. That concerns me more. A small retrospective study in the American Journal of Cardiology 15 March 2007, found a specificity of 99% for PE and a positive predictive value for PE of 97% when there is T wave inversion in V1 and III.

Not bad. Something to think about.