What can hypokalemia lead to in terms of cardiac ECG findings?

• A. ST elevation
• B. T wave flattening
• C. ST segment depression
• D. Prolonged QT interval

Answer: (C)

Hypokalemia, which is a condition characterized by low levels of potassium in the blood, has specific effects on the cardiac electrical activity that can be observed through an ECG. One of the hallmark ECG changes associated with hypokalemia is ST segment depression. This finding occurs because low potassium levels disrupt the normal repolarization process of the cardiac myocytes, which can lead to a manifestation of altered ventricular repolarization on the ECG.

In patients with hypokalemia, the cellular mechanisms of repolarization are affected due to the imbalance of potassium gradients across the cell membrane. As a result, the ST segment can appear depressed. Recognizing this change on an ECG is crucial as it can signify increased risks of arrhythmias and other cardiac complications due to the effects of low potassium levels on heart function.

While other ECG changes can occur with hypokalemia, such as T wave flattening or prolongation of the QT interval, ST segment depression is often regarded as one of the more direct manifestations.