Spontaneous tear in the intimal wall of a<unk><unk>  leading to a false lumen and intramural hematoma, similar to aortic<unk> 
Much more common in young women
Hormonal changes in vessel wall (eg pregnancy, contraceptives)
Shear forces
Fibromuscular dysplasia
Underling connective tissue disorder
Iatrogenic (during<unk>  angiography)
Coronary artery dissection
Cardiac
Left ventricular pseudoaneurysm
ST-segment elevation myocardial infarction 
Missile embolus
Post-MI 
Myocardial rupture
Previous MI with recurrent ischemia in same area