Mechanisms of aortic dissection
Intimal tear
Medial hemorrhage due to rupture of vasa vasorum, extending into the lumen
Location of initmal tear in aortic dissection
Near the aortic valve
Region of ligamentum arteriosum
Stanford classification of aortic dissection
Depending only on the location of the dissection, not on the location of the intimal tear
A: Ascending aorta is involved
B: Ascending aorta is not involved
DeBakey classification of aortic dissection
II ascending aorta
I originates in ascending aorta and extends at least till the arch
III descending aorta
Genetic conditions predisposing to aortic dissection
Marfan syndrome
Ehlers Danlos syndrome
Turner syndrome
Post cardiac surgery aortic dissection
Commonest cause of post cardiac surgery dissection is after aortic valve replacement
Echocardiogram in aortic dissection
Aortic dissection is diagnosed by visualizing the flap in more than one view, with independent motion and different colour flows in true and false lumens.
Transthoracic echo may miss one third of aoric dissections while transeosophageal can detect almost all cases. Distal ascending aorta and part of the proximal aortic arch may not be visualized well on transoesphageal echo due to the intervening air passages.
Acute aortic syndrome
Aortic dissection, penetrating aortic ulcer, intramural hematoma, pseudo aneurysm, impending rupture of a true aneurysm
All these conditions cause acute chest pain mimicking aortic dissection