Which of this patient\'s coronary arteries is most likely occluded?

A 61-year-old Caucasian male presents to the emergency room with severe substernal chest pain, diaphoresis, and nausea. Imaging reveals transmural myocardial infarction in the posterior 1/3 of the ventricular septum. Which of this patient’s coronary arteries is most likely occluded?

1.Left cirucumflex
2.left anterior descending
3.Diagonal perforators
4.Septal perforators
5.Right main


The artery supplying the posterior 1/3 of the ventricular septum is referred to as the “dominant” artery. In approximately 80% of people, the right main coronary artery (RCA) is dominant.
The coronary arteries originate as the right and left main coronary arteries, which exit the ascending aorta just above the aortic valve. Both the right and left coronary arteries subdivide into progressively smaller branches that then progress inward to penetrate the epicardium and supply blood to the transmural myocardium. The artery that supplies the posterior descending artery (PDA) determines the coronary dominance. The coronary circulation is “right dominant” if the PDA is supplied by the RCA.
American Family Physician published an article discussing the risks of heart attacks. Major risk factors for coronary heart disease include diabetes, high blood pressure, high cholesterol, male gender, advanced age, current or previous smoking, and either a father who had a heart attack before 55 years of age or a mother who had a heart attack before 65 years of age. Eating a healthy diet, exercising, stopping smoking, using lipid lowering medications if necessary, daily aspirin (for some individuals), and maintaining a healthy weight could help lower one’s risk of heart attacks.
Illustration A depicts the anatomy of the vasculature of the heart. Illustration B is a right anterior oblique view of the cardiac arterial supply. Be familiar with identifying various cardiac anatomy in different orientations.