Spontaneous Coronary Artery Dissection
(SCAD)
Overview
Arteries are strong tubes, or blood vessels, that carry blood from your heart to the rest of your body. They’re made up of three layers: a smooth inner layer, a thick middle layer, and a rough outer layer. A tear in the inner layer (tunica intima) of an artery is known as a spontaneous coronary artery dissection (SCAD). When this tear occurs, blood flows between the inner and outer layers of the artery, causing further separation of the layers of the artery wall, restricting the amount of blood flowing through it—or even blocking it entirely—and causing a heart attack.
An artery is composed of several layers, all surrounding where the blood flows, called the lumen. A lumen is the inside space of a tubular structure, akin to where fuel flows for a fuel line in a car. When this tear occurs, blood flows between the inner and outer layers of the artery, causing further separation of the layers of the artery wall. Essentially, the normal lumen of the artery becomes two lumens—one that feeds the downstream muscle (true lumen) and one that ends in a dead end (false lumen). The false lumen can compress the true lumen (where the blood is supposed to be flowing), restricting the amount of blood flowing through it or blocking it entirely and causing a heart attack.
About 80% of SCAD cases occur in young, healthy, and active people—30% occur in women* who recently had a child.1 Although SCAD is uncommon, there’s some risk for reoccurrence—up to 19% if you’ve already had SCAD.2 Because of this risk of reoccurrence, in addition to the condition spontaneously occurring, it’s important for SCAD patients to seek immediate treatment if they experience signs of a heart attack.
*The term “women” in the context of “women’s cardiovascular health” applies to individuals assigned female at birth (AFAB) who have a female biological reproductive system, which includes a vagina, uterus, ovaries, Fallopian tubes, accessory glands, and external genital organs.
*The term “men” in the context of “cardiovascular health” applies to individuals assigned male at birth (AMAB) who have a male biological reproductive system, which includes a penis, scrotum, testes, epididymis, vas deferens, prostate, and seminal vesicles.