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- 72 bpm
- Right axis deviation
- QRS - Prolonged (120ms)
- QT - Measured in lead aVL 440ms
- QT - Measured in leads V4-5 620-640ms
- ST Elevation leads aVR, aVL, V1-3
- ST Depression leads II, III, aVF, V4-6
- U waves best seen in precordial leads
- Associated apparent QT prolongation in precordial leads vs limb leads due to T-U fusion
- T wave inversion leads II, III, aVF, V4-6
- LVH criteria
- V4 R >26mm
- Largest Precordial S + R wave >45mm
- R wave in aVF ~20mm
- Features of hypokalaemia
- Prominent U waves
- Apparent QT prolongation due to T-U fusion in precordial leads
- Cause of / or contributing to T wave inversion & ST depression
- T wave & ST segment changes could be due to LVH
- Potential for ACS
- Needs serial ECG's
What happened ?
Patient's potassium was 2.1 mmol/L. Serial troponins were negative. Partial resolution of ST segment depression and resolution of U waves once K was corrected.
Hypokalemia ECG's on the Web
- ECG of the Week - We've had some examples of hypokalemia previous check them out here & here.
- Dr Smith's ECG Blog - multiple great examples of hypokalaemic ECGs here.
- Dr Ken Grauer's ECG Interpretation - A great walk through of ECG changes in hypokalaemia here.
- Amal Mattu's ECG Video - ECG findings in severe hypokalaemia here.
Life in the Fast Lane
- Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.