Cardiac Medicine Certification (CMC) Practice Exam

Which artery is primarily responsible for supplying the papillary muscles in a lateral wall myocardial infarction?

1. Left anterior descending artery

2. Right coronary artery

3. Circumflex artery

4. Pulmonary artery

The correct answer is: Circumflex artery

The circumflex artery is primarily responsible for supplying the papillary muscles located in the lateral wall of the left ventricle. In the context of a lateral wall myocardial infarction, it is crucial to recognize the role of the circumflex artery as it provides blood flow to the lateral aspects of the left ventricle, including the muscles that attach to the mitral valve, such as the papillary muscles. In patients experiencing a lateral wall myocardial infarction, the damage primarily occurs in the area supplied by the circumflex artery. The papillary muscles depend on adequate blood supply to maintain the structural integrity of the mitral valve apparatus; therefore, when the circumflex artery is compromised, the risk of ischemia or infarction of the papillary muscles increases, potentially leading to significant complications, such as mitral valve dysfunction. Other arteries mentioned play different roles; for instance, the left anterior descending artery mainly supplies the anterior wall of the left ventricle, while the right coronary artery primarily supplies the right side of the heart and the inferior wall in right-dominant coronary systems. The pulmonary artery is not involved in coronary circulation but rather carries deoxygenated blood from the right ventricle to the lungs. Thus, the role of the circum