A 60-year-old female presents with epigastric pain, nausea and vomiting,
heart rate of 50, and pronounced first-degree AV block on ER cardiac
monitor. Blood pressure is 130/80. The coronary artery most likely to be
involved in this process is the
A. Right coronary B. Left main
C. Left anterior descending
B. Circumflex
Ans. A. The right coronary artery supplies most of the inferior myocardium and supplies the AV node in over 70% of patients. Thus occlusion of this artery can cause ischemia of the AV node with AV block or bradycardia, as well as symptoms of an inferior MI as seen in this patient. AV block can occur with anterior MI related to LAD occlusion, but this generally implies a greater area of myocardial involvement and hemodynamic instability.
