Which ECG change is most likely seen with hypokalemia?

Hypokalemia, which refers to low levels of potassium in the blood, is known to produce specific changes in the electrocardiogram (ECG). Among these changes, increasingly prominent U waves are the hallmark characteristic associated with hypokalemia.

U waves are the small deflections that occur after the T wave in a normal ECG and are generally not prominent in healthy individuals. However, when potassium levels drop, the repolarization process of the cardiac muscle cells can be altered, leading to enhanced visibility and prominence of the U waves on the ECG. This change is particularly significant and can often be a crucial indicator of the underlying electrolyte disturbance caused by hypokalemia.

Monitoring U wave changes can therefore be a practical approach in clinical settings to assess potassium balance, especially in patients presenting with symptoms like muscle weakness or arrhythmias. This association makes the presence of increasingly prominent U waves a key finding that healthcare professionals look for when diagnosing hypokalemia.