Bradycardia can be caused by myocardial infarction in which region?

• A. Inferior wall
• B. Anterior wall
• C. Lateral wall
• D. Posterior wall

Answer: (A)

Bradycardia from a myocardial infarction most often points to involvement of the heart’s nodal conduction system, which is especially vulnerable when the inferior region is affected. In most people, the right coronary artery supplies the inferior wall and also feeds the AV node. If a right coronary artery occlusion causes an inferior wall infarction, the AV node can become ischemic and its ability to conduct impulses from the atria to the ventricles diminishes. That disruption leads to slower heart rates and, in some cases, varying degrees of AV block.

By contrast, anterior wall infarctions—coming from the left anterior descending artery—tend to impact the left ventricle and can cause other electrical disturbances, but bradycardia is less characteristic there. Lateral and posterior wall infarctions involve different vascular territories and are not as closely linked to nodal ischemia, so they’re less likely to produce bradycardia as a classic presentation.

So, the region whose infarction most reliably produces bradycardia is the inferior wall because its blood supply commonly feeds the AV node, and ischemia there directly impairs nodal conduction.