A 67-year-old woman with pulmonary hypertension (PH) presented with a 1-day history of worsening shortness of breath and pleuritic chest pain and was found to have a troponin T level of 3755 ng/L (ref. range 0-19 ng/L). An initial diagnostic workup in the emergency department (ED) led to an urgent left heart catheterization which revealed a 90% occlusive right coronary artery blood clot, even though a recent heart catheterization less than a month prior was completely unremarkable. Further workup led to the discovery of a patent foramen ovale (PFO) and an aneurysmal interatrial septum, suggesting the presence of a paradoxical embolism. While typically asymptomatic, a PFO is an important clinical entity that can lead to irreversible cardiac damage. Suspicion should be high for this finding in the case of an acute myocardial infarction (MI) with no clear cause, especially in a patient with elevated right heart pressures.