SCAD is the abbreviation for Spontaneous Coronary Artery Dissection. It is a rare condition that occurs when there is a tear in the wall of an artery supplying the heart. This can lead to a heart attack, as the blood supply to the heart is interrupted. The name SCAD can be broken down as follows:

• Spontaneous: there is no injury, apparent disease or other direct cause for the dissection of the coronary artery, it appears to "just happen".
• Coronary: dissections can happen in other parts of the body, but when it happens in a blood vessel supplying the heart muscle tissue, it can cause a heart attack.
• Artery: Arteries supply blood (carrying oxygen) to a muscle or organ of the body, veins carry the blood back to the heart.
• Dissection: the technical term for separation of the layers of the blood vessel wall

SCAD can present in different ways:

In some cases there is a visible dissection flap with a communication between the part of the artery supplying blood to the heart, and the split in the wall. In other cases this communication is not seen but there is an intramural haematoma, where the artery wall is damaged and a collection of blood leaks into the tissue. This causes a swelling which blocks the blood flow.