Elderly patient feeling generally unwell. PMHx of T2DM, hypertension, IHD, CCF, osteoarthritis. Describe the ECG.
Describe and interpret this ECG
ECG ANSWER and INTERPRETATION
- Bizarre appearing complexes
- Marked T wave peaking in V2-6.
- Gross QRS prolongation (~200 ms)
- Some leads (I, aVR) are starting to take on a sine wave appearance
The combination of…
- Bizarre complexes
- QRS prolongation
- Peaked T waves
- Sine wave appearance
… are all strongly suggestive of severe hyperkalemia.
This patient had a serum K of 9.2 mmol/L!
In this elderly patient with multiple medical problems, causes could include renal failure (e.g. due to diuretics, NSAIDs, intercurrent illness) or treatment with ACE-inhibitors, spironalactone or K-supplements.
The push-pull effect
- Hypokalaemia creates the illusion that the T wave is “pushed down”, with resultant T-wave flattening/inversion, ST depression, and prominent U waves
- In hyperkalaemia, the T wave is “pulled upwards”, creating tall “tented” T waves, and stretching the remainder of the ECG to cause P wave flattening, PR prolongation, and QRS widening