Response: Pulmonary embolism and shunt in acute myocardial infarction

We thank the authors for these clinically important observations relating to the management of right ventricular (RV) failure in the ED and their discussion of several interesting cases. Pulmonary embolism (PE) should be considered in the differential diagnosis of a patient presenting to the ED with acute RV failure. Additional etiologies to consider include valvular heart disease, tamponade physiology, and cardiomyopathies [ ]. Differentiation of PE and acute myocardial infarction (AMI) can be clinically challenging, as ST elevation in leads V1–V4 may be present in up to 5% of acute PE [ ]. The time pressure to achieve early revascularization for AMI can lead to delays in recognizing PE [ ]. Rarely, AMI and PE can present concomitantly due to paradoxical embolism from the PE across an atrial septal defect (ASD) or patent foramen ovale (PFO) causing AMI [ ]. Early cardiology consultation for echocardiography and possible revascularization are critical for this patient population [ ]. PE should remain on the differential diagnosis in patients with ECG changes suggestive of AMI, particularly for patients with severe hypoxemia without pulmonary edema or in those with clinical history suggestive of PE [ ].