Veins
The myocardium does not have blood flow to the arm. The myocardium is the muscle of the heart and therefore only supplies blood to the heart.
The Right Coronary Artery supplies blood to the inferior myocardium
The myocardium (middle layer) has the bulk of the muscle which pumps blood from the ventricles.
Oxygenated blood is brought to the myocardium by coronary arteries. These arteries are located all around he surface of the heart.
Unoxygenated
Veins. Veins carry unoxygenated blood towards the heart.
coronary
Coronary arteries
Infarction
Unoxygenated blood would be found in a vein.
Right Ventricle