Which artery is primarily responsible for 80% of inferior myocardial infarctions?

The right coronary artery is primarily responsible for 80% of inferior myocardial infarctions, which typically occur in the area supplied by the posterior descending artery, a branch of the right coronary artery. In right-dominant coronary systems, which is the case in the majority of individuals, the right coronary artery supplies blood to the inferior wall of the heart, including the right ventricle and parts of the left ventricle.

When there is a blockage in the right coronary artery, it can lead to ischemia and subsequent infarction of the inferior portion of the myocardium. Since this artery plays a vital role in supplying blood to this region, the incidence of inferior myocardial infarctions is significantly higher with occlusions in the right coronary artery compared to other coronary arteries.

The left anterior descending artery primarily supplies the anterior wall and septal regions, while the circumflex artery supplies the lateral and posterior walls of the left ventricle but is not associated with the majority of inferior myocardial infarctions. The left main coronary artery bifurcates into the two main coronary arteries and is less frequently blocked than the right coronary artery when considering isolated inferior infarctions.