What happens to the T-waves in hyperkalemia?

In the context of hyperkalemia, T-waves on an electrocardiogram (ECG) display characteristic changes due to the effects of elevated potassium levels on myocardial cells. In hyperkalemia, the increase in extracellular potassium concentration leads to alterations in cardiac depolarization and repolarization processes.

The T-waves specifically become tall and tented, reflecting a delayed repolarization of the myocardial cells. This is because elevated potassium causes a rise in the resting membrane potential, making it closer to the threshold for action potentials, and disrupting the normal ionic flow during repolarization. Consequently, the T-wave morphology changes to exhibit a tall, peaked appearance that is often described as "tented."

This finding is critical for clinicians as it serves as a visual indicator of the underlying electrolyte imbalance, prompting further evaluation and management of the patient's condition.