Spontaneous Left Main Coronary Artery Dissection

Case Presentation: Upon hearing of the death of her brother, a 35 yo woman experienced the sudden onset of retrosternal chest pain, SOB, diaphoresis, and syncope. She had no prior cardiac or neurologic history, nor family history of either. She was 5 weeks post-partum following the uneventful vaginal delivery of her 3rd child. She denied cocaine, alcohol, prescription or other drug use, HTN, DM, or dyslipidemia. There was a 10 year history of 5 cigarettes a day.

When examined in the ED 30 minutes after onset of Sx, vital signs and physical exam were unremarkable. Initial EKG demonstrated an idioventricular rhythm with inverted T waves in the anterior leads, and cardiac enzymes were strongly positive. V/Q scan was negative. Echocardiogram revealed LVEF of 25% with anteroapical hypokinesis, and no aortic dissection. Repeat EKG revealed ST segment elevations in the anterior leads. Emergent catheterization revealed a dissection of the left main coronary artery; the right coronary vessels were completely normal. The patient was taken to CABG, where LIMA LAD and radial artery obtuse marginal artery bypasses were successfully performed.

Immediate post-operative EKG revealed new ST segment elevations in the anterior leads. Repeat catheterization demonstrated complete dissection of the LAD to the apex with multiple dissection planes. The LAD was successfully repaired with multiple stents. Although the patient initially required intensive post-operative support including IABP, she recovered uneventfully and was discharged with LVEF 30% by echocardiography.

Discussion: Spontaneous coronary artery dissection, although very rare, is the most common cause of infarction in the post-partum period, and is lethal in more than 2/3 of all cases. The cause is poorly understood, but pathological evidence strongly suggests an autoimmune inflammatory component; at least one case has been successfully treated with prednisone and cytoxan. The left-sided coronary vasculature is involved in ~80% of cases, with ~18% involving the left main coronary artery (LMCA). Angioplasty has been successful in similar non-atherosclerotic lesions affecting the LMCA, but has never been attempted in a case of spontaneous dissection. Two prior cases have been reported in which LIMA LAD bypass was performed; both had positive outcomes. There are no prior reports of the use of arterial grafts in this syndrome.

Recurrent MI is not uncommon, occurring in ~21% of cases, almost exclusively as a result of a second spontaneous dissection.

Causality could not be established between this patient hearing bad news and the dissection of her coronary arteries. Although a transient catecholamine surge may have exacerbated an already existing arterial weakness, there is no other reasonable explanation except unfortunate coincidence.

This abstract was submitted as part of an Associate's competition amongst all residents in the state of Massachusetts, and was selected as one of only 4 abstracts to be given as an oral presentation at the 2002 Annual Meeting of the ACP-ASIM. The presentation won a second place award and was presented as a poster at the national competition in April, 2003. The abstract was required to conform to certain size and space restrictions.

Click Here to view the poster that was presented in San Diego at the National ACP-ASIM Conference. This file is in PDF format.

Thanks to Stewart Babbott MD, Michael Picchioni MD, and Steven Ryzewicz MD for their assistance in editing this abstract, with particular thanks to Dr. Babbott for his assistance with the poster.

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