Radiology Teaching Files > Case 4956139

Contributed by: Arman Forouzannia.
Patient: 96 year old female
History: 96yr old female with SOB of breath, orthopnea, chest pain.

Fig. 1: Saddle embolus at the bifurcation. Large thrombus burden in bilateral main pulmonary arteries.

Fig. 2: Saddle embolism at the bifurcation.

Fig. 3: Thrombus extending from the bifurcation to the left.

Fig. 4: High thrombus burden in the distal right pulmonary artery. Additional thrombus also seen on the left.

Fig. 5: More prominent right ventricular enlargment. Subtle suggestion of interventricular deviation at this level.

Fig. 6: Dilated right ventricle and deviated interventricular septum towards the left ventricle.
Findings: Large saddle pulmonary embolism extending into all lobar branches of the pulmonary artery system.  There is large thrombus burdon on the heart and there is evidence of right ventricular expansion and deviation of the interventricular septum suggesting right heart strain and right heart failure.  No significant reflux into the hepatic viens/IVC was demonstrated although this a classic additional finding.
Diagnosis: Saddle Pulmonary Embolism with Right Heart Strain.

Saddle thromboemboli occurs when pulmonary emboli occurs at  the level of the bifurcation of the pulmonary trunk and extends into the main right and left pulmonary arteries.

Such proximal thrombus are generally regarded as unstable, "in-transit" embolus, which can fragment spontaneously or secondary to treatment and obstruct multiple, distal pulmonary arteries. Often there are findings associated with right heart strain as a result of increased afterload on the right ventricle from a large thrombus burdun.  In the acute setting the RV cannot compensate for the afterload increase and there is development of right ventricular dilatation with pump failure (falling of the Starling Curve). 

The general understanding is that emergent interventional treament is required with catheter directed TPA. Patients with saddle embolism have also been clinically treated with various methods including IV heparin, IV TPA, or open thrombectomy. 

High mortality is generally associated with saddle pulmonary embolism and can be a cause of sudden cardiac arrest.


Short term clinical outcome of acute saddle pulmonary embolism, P Pruszczyk1, R Pacho2, M Ciurzynski3, M Kurzyna4, B Burakowska4, W Tomkowski4, A Bochowicz1 and A Torbicki4, Heart 2003;89:335-336

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Additional Details:

Case Number: 4956139Last Updated: 06-10-2006
Anatomy: Vascular/Lymphatic   Pathology: Vascular
Modality: CTExam Date: Access Level: Readable by all users
Keywords: saddle pulmonary embolism right heart strain

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