ECG of the Week: ECG of the Week - 30th July 2018

Wednesday, 1 August 2018

ECG of the Week - 30th July 2018 - Interpretation

This ECG is from a 69 yr old female who presented complaining of palpitations. She has a background of paroxysmal AF and her medications include a NOAC.

Click to enlarge

Rate:

Mean ventricular rate 96 bpm

Rhythm:

Bigemny

Sinus complex following by unifocal PVC in 1:1 relationship

Axis:

Normal

Intervals - sinus complexes:

PR - Normal (~140ms)
QRS - Normal (80ms)

Additional:

ST Depression leads I, II, III, aVF, V4-6
ST Elevation leads aVR and aVL
Significant baseline wander

There are multiple causes of PVC's and bigeminy including:

Anxiety
Altered sympathetic tone
Drug toxicity especially digoxin
Excess caffeine
Electrolyte disturbance
Ischaemia
Myocarditis

The presence of bigeminy can be very distracting and careful review of the ECG is required to make sure you're not missing anything. The presence of ST / T wave changes can be easily missed due to the expected ST segment abnormalities associated with PVC's creating a visual distraction.

I like to cover up the PVC's with a bit of paper so I can focus on the sinus complexes and then do the same for the sinus complexes as the PVC's can sometimes give additional clues as to what's going on. I think the ST changes in the sinus complexes are easier to appreciate when the PVCs are removed in the image below.