Blood flow in arteries in spontaneous coronary artery dissection (SCAD)
In spontaneous coronary artery dissection (SCAD), a tear forms in an artery in the heart. This can cause blood to pool in the area between the layers. Blood trapped between the layers can form a blood clot (hematoma). SCAD can reduce or block blood flow through the artery, which can cause a heart attack. However, a heart attack in SCAD is different from a heart attack caused by hardening of the arteries (atherosclerosis), shown in the bottom image.