In suspected second- or third-degree heart block, how should pacing be approached?

• A. Atropine is first-line therapy
• B. Transcutaneous pacing should be pursued directly
• C. Begin amiodarone
• D. Observe

Answer: (B)

When there is suspected high-grade AV block, the priority is to ensure a reliable heart rate and adequate blood flow. The fastest way to achieve this is temporary pacing, started promptly as a bridge to a more durable solution. In second-degree Mobitz II or third-degree block, the conduction failure lies below the AV node, so impulses from the SA node may not reach the ventricles. Medications that increase AV nodal conduction, like atropine, often fail in this situation because the block is distal to the AV node, making pacing the more dependable option. Amiodarone is aimed at tachyarrhythmias and can worsen bradycardia, so it isn’t appropriate here. Observation leaves the patient at ongoing risk of deterioration, which is why pacing is pursued directly to stabilize rhythm. Transcutaneous pacing provides immediate, temporary support while preparing for longer-term pacing, such as transvenous pacing or a permanent pacemaker.