Which drug can be used to combat bradycardia?

• A. Atropine
• B. Lidocaine
• C. Amlodipine
• D. Epinephrine

Answer: (A)

Bradycardia happens when the heart rate is slow, often from too much vagal (parasympathetic) input to the heart. To raise the rate quickly, you need to block that parasympathetic influence on the SA and AV nodes. Atropine does exactly this: it blocks muscarinic receptors, removing the vagal braking and letting the SA node fire faster and conduction through the AV node speed up. This makes atropine a first-line option for symptomatic bradycardia, given as a rapid IV bolus and repeated as needed.

Lidocaine won’t help with a slow heart rate because it’s used to treat ventricular arrhythmias, not bradycardia. Amlodipine is a calcium channel blocker that can slow the heart rate further, so it would worsen bradycardia. Epinephrine can increase heart rate via adrenergic receptors, but it’s typically reserved for more severe situations like cardiac arrest or shock, not as the initial treatment for isolated bradycardia.