Cardiac Medicine Certification (CMC) Practice Exam

What is a common electrical disturbance associated with anterior wall myocardial infarction?

1. Complete heart block

2. Atrial fibrillation

3. Increased heart rate

4. Junctional rhythm

The correct answer is: Complete heart block

The association of complete heart block with anterior wall myocardial infarction can be attributed to the anatomical and electrical properties of the heart. Anterior wall myocardial infarctions typically affect the left anterior descending artery, which supplies a significant portion of the heart's conducting system, particularly the bundle branches and the anterior wall of the left ventricle. Damage to the conduction system due to ischemia or infarction can lead to disturbances in electrical transmission. Complete heart block occurs when there is a failure of conduction through the atrioventricular node or the bundle branches, which can occur in cases where the infarct impacts the bundle branches that serve the anterior wall. This condition may present as a sudden drop in heart rate and can lead to significant hemodynamic instability, making it a critical issue to monitor in patients suffering from anterior wall myocardial infarctions. In contrast, while conditions like atrial fibrillation, increased heart rate, and junctional rhythm can be seen in various cardiac conditions, they are not specifically tied to anterior wall myocardial infarction in the same way that complete heart block is. Atrial fibrillation, for example, is more likely to occur in cases of atrial enlargement or rapid ventricular response. Increased heart rate can occur due to various factors like stress or