Prognosis

Bradycardias are common within the first 24 hours ^b but are more problematic with inferior MI. ^a

Note:

• A fifth of patients have bradycardia within 4 hours of symptom onset 21% (95% CI: 17% to 25%), but many settle - only a tenth have bradycardia after this time (9.0%: 95% CI: 4.2% to 13%). ^b
• One in ten patients with an inferior MI go onto develop complete heart block (9.4%: 95% CI: 7.1% to 11%). ^a
• Second or third degree heart block within 24 hours of admission is not clearly associated with death. ^b