Fibromuscular Dysplasia with Spontaneous Coronary Artery Disease Presenting as Acute Myocardial Infarction

A 40-year-old female presented to a rural hospital with crushing substernal chest pain. An initial electrocardiogram showed ST elevation in lead II and aVF with elevated troponin I. She was immediately transferred to a tertiary care hospital. An emergent coronary angiogram did not show any significant coronary artery disease. On the second day, the patient experienced recurrence of severe chest pain with ST elevations in leads I, aVL, V5-V6, ST depressions in V1-V3, T-wave inversion over V2-V5. The troponin I level increased to > 40 ng/ml (normal 0.0 to 0.04 ng/ml). An emergent angiogram was performed revealing local dissection of the mid to distal left main coronary artery and a totally occluded diagonal artery. It was deemed unsafe to perform percutaneous coronary intervention because it was a non-flow limiting left main coronary artery dissection and was difficult to cannulate with the guide catheter. Subsequently, an elective angiogram was performed after a 48-hour interval to evaluate the progression of dissection and to make a definitive decision for revascularization versus medical management. On the third angiogram, stenosis seen in the diagonal branch on the previous angiogram progressed to dissection, and local dissection of the left main coronary artery seen on the previous angiogram spontaneously resolved. The patient was symptom-free and hemodynamically stable. It was decided to manage the patient conservatively due to the spontaneous resolution of occlusion in the diagonal artery and dissection of the left main coronary artery. The patient was started on conservative medical treatment. A magnetic resonance angiography of the right internal carotid artery revealed a "string of beads" appearance, which confirmed the diagnosis of fibromuscular dysplasia. She was followed closely in the clinic and has remained asymptomatic for the past one year.