Spontaneous Left Main Coronary Artery Dissection and the Role of Intravascular Ultrasonography

Objective. Spontaneous left main coronary artery (LMCA) dissection is a rare event with an unknown incidence and high risk of sudden cardiac death. The diagnosis of LMCA dissection is often challenging given the limitations of 2-dimensional angiography. The 3-dimensional perspective of intravascular ultrasonography (IVUS) is often indispensable in confirming or excluding the diagnosis of spontaneous LMCA dissection. We report 2 cases of spontaneous LMCA dissection with unique angiographic presentations wherein IVUS was essential in defining the extent of LMCA involvement and facilitated the subsequent referral for emergent coronary artery bypass grafting. Methods. Two patients presented to our facility with acute coronary syndrome prompting coronary angiography, which was notable for an unusual angiographic appearance of the LMCA. Intravascular ultrasonography was performed in each case, revealing spontaneous LMCA dissection. Results. Intravascular ultrasonography permitted the prompt diagnosis and aided in definitive surgical intervention in our 2 cases of spontaneous LMCA dissection. Conclusions. Intravascular ultrasonography is a useful adjunctive imaging modality in the diagnosis and management of spontaneous LMCA dissection.