Hypokalemia electrocardiogram: Difference between revisions
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==Electrocardiogram== | ==Electrocardiogram== | ||
===ECG Changes=== | ===ECG Changes=== | ||
# [[ST segment depression]], decreased [[T wave]] amplitude, prominent [[U waves]] | # [[ST segment depression]], decreased [[T wave]] amplitude, and prominent [[U waves]]: | ||
#* Seen in 78% of patients with a K < 2.7 meq | #* Seen in 78% of patients with a K < 2.7 meq | ||
#* Seen in 35% of patients with a K > 2.7 and < 3.0 | #* Seen in 35% of patients with a K > 2.7 and < 3.0 | ||
| Line 17: | Line 17: | ||
# Increase in the amplitude and duration of the [[P-wave]] | # Increase in the amplitude and duration of the [[P-wave]] | ||
# [[Cardiac arrhythmias]] and [[AV block]] | # [[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 | |||
#* [[Premature ventricular complex]] | |||
#* [[Ventricular tachycardia]] | |||
#* [[Ventricular fibrillation]] | |||
===ECG Examples=== | ===ECG Examples=== | ||
Latest revision as of 20:36, 21 October 2014
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Hypokalemia Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Hypokalemia electrocardiogram On the Web |
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American Roentgen Ray Society Images of Hypokalemia electrocardiogram |
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Risk calculators and risk factors for Hypokalemia electrocardiogram |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]; Assistant Editor(s)-In-Chief: Jack Khouri
Overview
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.
Electrocardiogram
ECG Changes
- ST segment depression, decreased T wave amplitude, and prominent U waves:
- Seen in 78% of patients with a K < 2.7 meq
- Seen in 35% of patients with a K > 2.7 and < 3.0
- Seen in 10% of patients with a K > 3.0 and < 3.5
- U waves are also prominent in bradycardia and LVH
- 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
ECG Examples
Shown below is an example of hypokalemia with long QT interval, ST segment depression, low T waves amplitude and TU wave fusion.
Shown below is an example of hypokalemia with Left Ventricular Hypertrophy.
The EKG below demonstrates characteristics of hypokalemia including: T wave inversions and U waves circled in red; flattening of ST segment and prolonged Q- U interval as circled in green.
The EKG changes of hypokalemia are rapidly reversible with potassium repletion.