Case Presentation: A 50 year-old female with a past medical history of migraines on triptan therapy presented to an outside ED with a 1 day history of chest pain and was transported emergently to a tertiary hospital for suspected STEMI. She had a troponin of < 0.012 with inferior ST elevations on ECG. STEMI was consequently activated and her chest pain diminished with fentanyl. She was started on aspirin and heparin gtt.She described the pain as if someone were sitting on her chest. The pain radiated to her right arm, but not her left. She sat up in bed for 10-25 min in an attempt to alleviate the pain. However, the pain did not change and she decided to go to the ED. She reported that she last experienced chest pain 5 years ago, but it resolved within minutes, therefore she never pursued further work up. She endorsed recent progressively increasing fatigue and exhaustion. She denied any nausea, abdominal pain, diaphoresis, shortness of breath, lightheadedness, dizziness, or syncope. She denied any prior cardiac history. No CAD in her family, however father does have atrial fibrillation. She did not have a history of hypertension, hyperlipidemia, or diabetes. She is a social drinker and never smoker. No illicit drug use. Reported 15 year triptan use for treatment of her chronic migraines.

Discussion: The patient’s cardiac catheterization reassuringly did not show any signs of CAD, which coupled with her normal serum troponin effectively ruled out ACS as an etiology of the patient’s pain. Bedside ultrasound showed a large mass in the left atrium. Her TTE showed a mobile large-sized spherical mass in the left atrial cavity attached to the atrial septum with a stalk at the aortic root. MRI showed a heterogeneously enhancing hypervascular mass with areas of internal myxomatous changes arising from the left interatrial septum filling the majority of the left atrium measuring approximately 5.5 x 3.8 x 4.3 cm all suggestive of cardiac myxoma. She underwent left atrial myxoma resection and septal reconstruction with bovine pericardial patch via trans-septal approach without any surgical complications. The most likely etiology is that her cardiac myxoma caused transient inferior ST elevations from small coronary embolus. Given her history of chronic abortive triptan therapy and her newly discovered hypervascular left trial tumor, it is also possible that she may have had a coronary vasospasm as the underlying cause of her chest pain with transient ST elevations.

Conclusions: It is important to be aware of the symptoms that atrial myxomas can mimic particularly chest pain in the setting of transient ST elevations from coronary embolus. Bedside TTE are a great modality for initial screening with formal TTE and cardiac MRI confirming the diagnosis. Cardiac myxomas should be kept on the differential as the cause of chest pain presenting with transient ST elevations, however with no findings of coronary occlusion on catheterization. Cardiothoracic surgical resection leads to a favorable prognosis.