Saddle pulmonary embolism (SPE) is a severe and life-threatening condition when a blood clot (embolus) becomes lodged in the main pulmonary artery, blocking blood flow to both lungs. The term “saddle” refers to the shape of the clot, which straddles the bifurcation of the pulmonary artery, resembling a saddle.
The symptomatology of SPE can be highly variable and ranges from mild chest pain and dyspnea to cardiovascular collapse, often due to right heart failure. Options include blood thinners, thrombolytic therapy, mechanical thrombectomy, and open surgery. As with any clot, it’s important to identify any provoking risk factors (surgery, malignancy, immobility, hormone-based contraceptives, etc.) that can be addressed or modified.
In this chest CT (PE protocol), one can appreciate the filling defect in the main pulmonary artery (mPA) straddling the bifurcation. Furthermore, there is CT evidence of RV strain due to the increased afterload of the pulmonary vasculature.