ECG library
Hypokalemia
coreThe vomiting patient from the alkalosis case: potassium 2.9.
25 mm/s · 10 mm/mV · synthetic tracing
100%
Calipers:2000 ms50.0 small boxes30 bpm if R-RDrag the orange markers. One small box = 40 ms.
Key findings
- Flat T waves
- U waves after the T
- Apparent long QT (really QU)
Learning points
- The U wave is hypokalemia's signature; look after the T in V2 to V4.
- Hypokalemia potentiates digoxin toxicity and torsades; the QT you measure may be a QU.
- Refractory hypokalemia is hypomagnesemia until proven otherwise.
Connected