Neuroleptics have a risk of which cardiac complication?

• A. Hypertension
• B. Atrial fibrillation
• C. Dysrhythmias such as Torsades de Pointes due to QT prolongation
• D. Myocardial infarction

Answer: (C)

Neuroleptics can prolong the heart’s repolarization phase, showing up as a longer QT interval on the ECG. This happens because many of these drugs block the IKr (hERG) potassium channels in cardiac cells, delaying repolarization. When repolarization is extended, the heart becomes more susceptible to early afterdepolarizations, which can trigger a rapid, irregular ventricular rhythm called torsades de pointes. This arrhythmia can collapse into more dangerous rhythms, making it a well-recognized and serious cardiac risk with these medications.

Other options don’t fit this typical pattern. Hypertension isn’t a direct, characteristic effect of neuroleptics, and atrial fibrillation isn’t the hallmark drug-induced issue for this class. Myocardial infarction can occur for various reasons but isn’t the classic cardiac complication taught for neuroleptics; the QT-prolongation–torsades link is the key concept to remember. In practice, monitoring QT interval and electrolytes helps mitigate this risk, especially with agents known to affect QT more strongly.