What heart rhythm changes may occur in a patient with hypocalcemia?

In cases of hypocalcemia, one significant change observed on an electrocardiogram (ECG) is the prolonged QT interval, which is directly related to the decreased levels of calcium in the blood. This prolongation affects the duration of the cardiac action potential, leading to a longer QT interval. Additionally, the ST segment can also be affected, often presenting as being longer due to the influence of low calcium levels on myocardial electrical activity.

The prolonged QT interval poses a risk of potentially life-threatening arrhythmias, such as torsades de pointes, as the heart's electrophysiological properties are altered. The relationship between calcium homeostasis and cardiac electrical activity emphasizes the critical role calcium plays in maintaining normal heart rhythm. Thus, in the context of hypocalcemia, recognizing these changes on an ECG is vital for timely diagnosis and management in critical care settings.