If a patient presents with STEMI without any evidence of atherosclerotic plaque in the coronaries, it raises the suspicion of an embolic coronary occlusion. Although the simultaneous occurrence of STEMI and Pulmonary Embolism (PE) is infrequent, when present, it suggests Paradoxical Embolism (PDE) through a PFO. Our case highlights this unique scenario.

Our patient is a 48-year-old female, lifelong athlete, who was not expected to have atherosclerotic heart disease; she presents with cardiac arrest secondary to an acute inferior ST elevation myocardial infarction. The patient was in her usual state of health, physically very active, performing daily exercise; on the eventful day, she complained to a family member of the sudden onset of severe chest and back pain, followed by a witnessed cardiac arrest at home. When EMS arrived, no shockable rhythm was noted, CPR was initiated, and eventually she was successfully resuscitated. A 12-lead electrocardiogram (ECG) in the field showed inferior ST-segment elevation (Figure 1), consistent with myocardial infarction. After being transported to the emergency room, she underwent urgent computer tomography angiography (CTA) to rule out aortic dissection, which revealed bilateral pulmonary emboli (Figure 2) without right ventricular strain.

Figure 1.12-lead electrocardiogram (ECG) in the field showed inferior ST-segment elevation.

As pulmonary embolism was not a saddle and no evidence of RV strain, likely this cardiac arrest related to acute myocardial injury. She was emergently taken to the cardiac catheterization lab to undergo coronary angiography, which revealed thrombotic occlusion of the mid-right coronary artery (RCA) (Figure 3). After successful mechanical aspiration of the thrombus, the angiography exhibited no coronary plaque (Figure 4). This raised the question of an embolic phenomenon in the coronary artery, prompting a transthoracic echocardiogram that demonstrated right-to-left shunting of saline bubbles, suggesting a patent foramen ovale (PFO). Our patient had right to left shunt without any evidence of right ventricular RV strain but probably patient had intermittent high right atrial pressure especially during Valsalva maneuver. Lower extremities doppler study was also performed which was negative for DVT. A transesophageal echocardiogram confirmed this (Figure 5). The patient was subsequently discharged on anticoagulation therapy Apixaban along with aspirin and Prasugrel in a stable condition. Apixaban was discontinued after 6 months. After a few months, the patient underwent a successful percutaneous closure of the PFO (Figure 6). Patient remains on DAPT (Dual antiplatelet therapy) for total 12 months from initial event. Three years after her initial event, she remains free from any recurrent episodes.

Figure 2.Computer tomography angiography showing bilateral pulmonary emboli.

Figure 3.Thrombotic occlusion of the mid-right coronary artery (RCA).

Figure 4.Normal coronaries after mechanical aspiration of the right coronary artery.

Figure 5.Transesophageal echocardiogram confirming patent foramen ovale.

Figure 6.Percutaneous closure of the PFO angiography.

Acute coronary occlusion due to paradoxical embolism is rare, but an astute physician can arrive at the correct diagnosis or have a high suspicion if the following scenarios are present. If no atherosclerotic disease is noted after clearing the thrombus in the coronaries, and 1) there is a concomitant diagnosis of pulmonary embolus, or 2) if the patient presents with concomitant stroke, or systemic embolus. Our patient presented with PE and heart attack, leading to suspicion for paradoxical embolism (PDE) through a PFO, which was promptly diagnosed and closed successfully.