Which medication is commonly used to treat premature ventricular contractions (PVCs)?

Lidocaine is a class 1b antiarrhythmic medication that is often used to treat ventricular arrhythmias, including premature ventricular contractions (PVCs). Its mechanism involves stabilizing the cardiac membrane, making it less likely to become overly excitable. Lidocaine is particularly effective at suppressing abnormal electrical activity in the ventricles, which is a hallmark of PVCs.

The other medications listed have different primary uses. Atenolol is a beta-blocker primarily used to manage hypertension and angina, and it can be helpful in some arrhythmias, but it is not the first choice specifically for PVCs. Diltiazem is a calcium channel blocker used mainly for controlling heart rate in conditions like atrial fibrillation or for managing hypertension, and it does not have primary indications for treating PVCs. Epinephrine is a powerful sympathomimetic agent that can increase heart rate and contractility, but it is not used for managing PVCs and can actually exacerbate arrhythmias in some cases.

Therefore, lidocaine stands out as the appropriate choice specifically for treating PVCs due to its action on the cardiac electrical conduction system.