Which of the following is a contraindication for beta-blockers?

• A. Hypertension
• B. Second-degree AV block
• C. Asthma
• D. Hyperlipidemia

Answer: (B)

Beta-blockers slow heart rate and also reduce conduction through the AV node. In someone with a second-degree AV block, the AV node already struggles to pass impulses from the atria to the ventricles. Adding a beta-blocker can further slow or block this conduction, potentially causing severe bradycardia or progression to complete heart block. That makes it a contraindication.

Hypertension isn’t a contraindication; beta-blockers are commonly used to treat it. Asthma is a concern because nonselective beta-blockers can trigger bronchospasm, so if one is needed, a cardioselective agent is preferred and used with caution. Hyperlipidemia also isn’t a contraindication.