What change in the electrocardiogram (ECG) is possible when administering haloperidol (Haldol)?

The administration of haloperidol, an antipsychotic medication, can lead to a prolonged QT interval on the electrocardiogram (ECG). This is significant because a prolonged QT interval increases the risk of developing life-threatening arrhythmias, such as Torsades de Pointes. The mechanism behind this effect is related to haloperidol's ability to block certain potassium channels responsible for repolarization of the cardiac action potential. As a result, there is a delay in the repolarization phase, which manifests as a prolonged QT interval.

Understanding this effect is crucial for healthcare providers, as monitoring the ECG of patients receiving haloperidol is important to avoid potential cardiac complications. Patients with existing risk factors for prolonged QT, such as electrolyte imbalances or concurrent use of other medications that affect the QT interval, are at particular risk and require closer monitoring.

In contrast, the other options do not accurately describe the typical ECG changes associated with haloperidol administration. A shortened QT interval is not a known effect of this medication, nor is there evidence showing that haloperidol consistently leads to elevation of ST segments or bradycardia as direct outcomes. Thus, recognizing the potential for a prolonged QT interval allows for proactive management of patients receiving