In this issue of the Journal, Pinney and Wasserman describe the case of a patient who survives acute aortic dissection complicated by occlusion of the left main coronary ostium and anterior myocardial infarction (MI), due in part to the fortuitous presence of an anomalous left circumflex artery. The case illustrates the challenges of diagnosing aortic dissection, even in the current era of accurate and rapid aortic imaging, in individuals with concurrent acute MI. These comments are focused in this comment on two key aspects of the case: (1) How commonly do acute aortic dissections lead to myocardial ischemia and MI? and (2) When should clinicians consider ruling out acute aortic dissection in the setting of acute MI?