(164) The Silent Thief: Aortic Dissection Presenting as Myocardial Infarction

Introduction: Acute myocardial infarction as a result of acute Stanford type A aortic dissection is a rare but devastating event, occurring in approximately 3% of patients with aortic dissection. Differentiating acute Stanford A aortic dissection with coronary malperfusion from true acute myocardial infarction is challenging and misdiagnosis is prevalent in patients with ST-segment elevation on initial ECGs. Inappropriate treatment with antiplatelet and thrombolytic agents can provoke severe hemorrhage and can be fatal.

Description: We illustrate a case of an 83-year-old female with a past medical history of hypertension presented to the emergency department with chest pain. EKG revealing inferolateral STEMI. Patient was initiated on heparin and transported for immediate PCI. Coronary angiography revealed an ascending aortic dissection extending into the right coronary artery (RCA). A drug-eluting stent was placed in the RCA and the patient was then immediately transitioned to the operating room for emergent Bentall procedure consisting of aortic root and valve replacement as well as coronary artery bypass graft of the RCA. Post-operatively, the patient's course was complicated by undifferentiated shock with severe hypotension and elevated lactate. Transesophageal echocardiogram showed that the dissection had progressed to the level of the iliac arteries. CT angiography revealed contrast extravasation, severe narrowing of the subclavian and iliac arteries, and a thrombosed false lumen. The patient then developed an abrupt loss of her left lower extremity pulses necessitating an emergent endovascular procedure with placement of peripheral stents in the iliac and left mid-common iliac arteries.

Discussion: Although angina with ST elevations on EKG often elicit a reflexive course of treatment with immediate thrombolytics and antiplatelet agents, it is imperative to consider a wider differential as illustrated by the case described above. Type A aortic dissections with extension into the coronary arteries present with many identical findings and should be considered when presented with ST-elevation myocardial infarction, especially in the inferior leads and risk factors or historical data that elevates the risk for dissection