Table of Contents
What is hyperkalemia in ECG?
The ECG findings of hyperkalemia change as the potassium level increases, from slightly high levels to very high levels. The ECG findings include: Peaked T waves best seen in the precordial leads, shortened QT interval and, at times, ST segment depression.
What does hyperkalemia look like on an ECG strip?
The ECG manifestations associated with hyperkalemia include: Prominent T waves. PR-interval prolongation. Loss of the P wave.
Why does hyperkalemia affect ECG?
Early changes of hyperkalemia include peaked T waves, shortened QT interval, and ST-segment depression. These changes are followed by bundle-branch blocks causing a widening of the QRS complex, increases in the PR interval, and decreased amplitude of the P wave (see the images below).
Why does hyperkalemia cause wide QRS?
As serum potassium levels increase to greater than 6.5 mEq/L, the rate of phase 0 of the action potential decreases, leading to a longer action potential and, in turn, a widened QRS complex and prolonged PR interval.
What ECG changes occur with hypokalemia?
ECG changes typically occur when serum potassium is < 3 mEq/L (< 3 mmol/L), and include ST segment sagging, T wave depression, and U wave elevation. With marked hypokalemia, the T wave becomes progressively smaller and the U wave becomes increasingly larger.
What are the ECG changes in hypokalemia?
ECG changes include flattening and inversion of T waves in mild hypokalemia, followed by Q-T interval prolongation, visible U wave and mild ST depression4 in more severe hypokalemia. Severe hypokalemia can also result in arrhythmias such as Torsades de points and ventricular tachycardia.
How does potassium affect ECG?
When potassium levels are <2.7 mmol/L, changes in the ECG include dynamic changes in T-wave morphology (T-wave flattening and inversion), ST-segment depression, and U waves, which are often best seen in the mid-precordial leads (V1–V4).
How is hyperkalemia treated in ECG?
Patients with hyperkalemia and characteristic ECG changes should be given intravenous calcium gluconate. Acutely lower potassium by giving intravenous insulin with glucose, a beta2 agonist by nebulizer, or both. Total body potassium should usually be lowered with sodium polystyrene sulfonate (Kayexalate).
What does EKG look like with low potassium?
Similar to elevated potassium levels, low potassium levels can cause myocardial arrhythmias and significant ectopy. EKG changes can include increased amplitude and width of P wave, T wave flattening and inversion, prominent U waves and apparent long QT intervals due to merging of the T and U wave.
When Is ECG used in hypokalemia?
ECG changes generally do not manifest until there is a moderate degree of hypokalaemia (2.5-2.9 mmol/L). The earliest ECG manifestation of hypokalaemia is a decrease in T wave amplitude.
How is hypokalemia detected on ECG?
Electrocardiographic characteristics associated with hypokalemia include dynamic changes in T-wave morphology, ST-segment depression, and U waves, which are often best seen in the mid-precordial leads (V2–V4). The PR interval can also be prolonged along with an increase in the amplitude of the P wave.
How does potassium affect an ECG?