A 55-year-old man is admitted with complete heart block (third-degree AV block) following inferior STEMI. His rate is 42 bpm with a stable blood pressure of 90/60 mmHg. The CORRECT initial management is:

• A Immediate permanent pacemaker implantation
• B IV atropine 1 mg bolus; if no response, transcutaneous pacing
• C IV dopamine infusion; no pacing needed for inferior MI
• D Temporary transvenous pacemaker; observe for spontaneous recovery (often resolves within 2 weeks) ✓

Explanation

Complete AV block complicating inferior STEMI is typically due to increased vagal tone and ischaemia of the AV node (supplied by RCA). It is almost always transient, resolving within days to 2 weeks. Management involves temporary transvenous pacing if the patient is haemodynamically unstable or symptomatic (rate <40 bpm); permanent pacing is usually not required. Unlike anterior STEMI-associated AV block (infranodal, more persistent), inferior MI block is supranodal with narrow escape rhythm. Atropine may help transiently but is not definitive.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

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Written and medically reviewed by the StethoPrep medical team.