- Acute coronary syndrome (ACS) involves rupture or erosion of a coronary plaque with exposure of the subendothelial matrix to circulating blood and subsequent platelet adhesion, platelet activation, and platelet aggregation
- A thrombus forms, resulting in partial or complete occlusion of the lumen of the coronary artery
- The initial ECG is nondiagnostic in up to 50% of patients presenting with chest pain, but remains a critical part of the evaluation
- Complete heart block (CHB) may be associated with an anterior or inferior wall MI
- High degree AV block is associated with an increase in mortality in patients with an inferior or anterior myocardial infarction
- Complete heart block with inferior MI generally results from an intranodal lesion and isassociated with a narrow QRS complex and develops in a progressive fashion from 1st to 2nd to 3rd degree block
- Patients with inferior MI and CHB may be resistant to atropine and its use during active ischemia may cause ventricular fibrillation!
- Temporary transvenous pacing is recommended
- Patients with inferior MI and CHB typically don’t need permanent pacing as the rhythm is transient and resolves within 5-7 days
Click on the link below to see an ECG of inferior MI with complete heart block!