How does hyperkalemia appear on an ECG?

Hyperkalemia, which is an elevated level of potassium in the bloodstream, has distinct characteristics on an electrocardiogram (ECG). The correct answer highlights these key features: peaked T waves, widened QRS complexes, and the potential loss of P waves.

The peaked T waves are often the first ECG change that can be observed as potassium levels rise. This occurs due to alterations in the cardiac muscle's repolarization process. As hyperkalemia progresses, the widening of the QRS complex indicates that conduction through the ventricles is also becoming impaired. In severe cases, the P waves may become less visible or disappear altogether, indicating that the atrial activity is compromised.

The other choices do not accurately reflect the expected ECG changes associated with hyperkalemia. Flat T waves, a prolonged QT interval, and inverted T waves can be seen in other conditions but are not characteristic of hyperkalemia itself. Understanding these specific ECG changes is crucial for recognizing and managing the complications associated with high potassium levels effectively.