Hypokalemia electrocardiogram On the Web
American Roentgen Ray Society Images of Hypokalemia electrocardiogram
The most notable EKG findings in hypokalemia are due to the delayed ventricular repolarization, manifesting as (QT-U) with prominent U waves. The EKG changes of hypokalemia are commonly seen at potassium levels < 3 meq/Li. 90% of the patients with potassium levels <2.7 meq/L have abnormal ECG findings.
- ST segment depression, decreased T wave amplitude, and prominent U waves:
- Prolongation of the QRS duration
- Uncommon except in severe hyperkalemia
- Increase in the amplitude and duration of the P-wave
- Cardiac arrhythmias and AV block
- Contrary to popular belief there is not prolongation of the QTc, this is artifactually prolonged due to the U wave. In some cases there is fusion of the T and U waves making interpretation impossible.
- Ventricular ectopy
Shown below is an example of hypokalemia with Left Ventricular Hypertrophy.
The EKG changes of hypokalemia are rapidly reversible with potassium repletion.