Which ECG changes are most commonly seen in hyperkalemia?

In cases of hyperkalemia, which refers to elevated levels of potassium in the blood, specific changes in the electrocardiogram (ECG) are characteristic. The most prominent ECG changes include a widened QRS complex and tall, peaked T waves.

The widening of the QRS complex indicates that the conduction time through the ventricles is prolonged, which occurs due to the effects of high potassium levels on the myocardial cells. Elevated potassium levels impact the cell membrane's resting potential, leading to slower depolarization and repolarization, thus resulting in the characteristic wide QRS.

Additionally, tall, peaked T waves are often one of the earliest signs of hyperkalemia. The T wave changes reflect alterations in the repolarization phase of the cardiac cycle, directly linked to the increase in extracellular potassium, which makes repolarization occur more rapidly but with a different morphology—often leading to a more peaking appearance of the T wave.

Considering the other options, while a shortened PR interval could potentially be seen in other conditions, it is not a hallmark of hyperkalemia. A regular rhythm does not specifically indicate hyperkalemia and can occur in various conditions. Inverted T waves may be associated with different electrolyte imbalances or ischemia