What does hyperkalemia cause on an EKG?

Hyperkalemia, which refers to elevated potassium levels in the blood, has characteristic effects on the electrocardiogram (EKG). One of the earliest EKG changes seen with hyperkalemia is the development of peaked T waves. These tall, narrow, and symmetrical T waves are a direct reflection of altered repolarization effects caused by high potassium levels.

As potassium concentration increases, it affects the myocardial cells, leading to a more rapid repolarization, which manifests as the peaked appearance of the T waves on the EKG. This change can serve as an important indicator for clinicians to identify hyperkalemia promptly, as it may lead to more serious arrhythmias if not addressed.

In contrast, flat T waves, U waves, and QT prolongation are more associated with different clinical scenarios or electrolyte imbalances. Flat T waves may indicate ischemia or hypokalemia, U waves are commonly seen in scenarios of hypokalemia or certain drug effects, and QT prolongation is often linked to various conditions such as congenital long QT syndrome or electrolyte imbalances like hypocalcemia. Thus, the specific feature of peaked T waves aligns distinctly with the presence of hyperkalemia.