Which ECG findings are commonly associated with hypokalemia?

• A. Peaked T waves
• B. Prominent U waves
• C. Narrow QRS complexes
• D. Shortened QT interval

Answer: (B)

Prominent U waves are a hallmark finding on an electrocardiogram (ECG) associated with hypokalemia. When potassium levels are low, the repolarization of the cardiac muscle can be altered, resulting in the presence of U waves, which appear as small waves following the T wave. These U waves can become more pronounced as the degree of hypokalemia increases.

Additionally, under hypokalemic conditions, the T wave can become flattened, although this is not the primary characteristic. As potassium affects the electrical activity in the heart, the altered repolarization can lead to these prominent U waves. This is why recognizing U waves on an ECG is critical for assessing a patient's potassium levels and related cardiac risk.