A rare case of simultaneous pulmonary and paradoxical emboli with a thrombus straddling a patent foramen ovale

Abstract

Background: Paradoxical embolism is a rare event and the exact contribution of patent foramen ovale in stroke is unclear. Intracardiac thrombi or 'embolus-in-transit' are associated with high mortality. Acutely elevated pulmonary arterial pressure due to pulmonary embolism or Valsalva maneuver make foramen ovale patent and promote right to left migration of intraatrial clot. A large thrombus trapped during its passage produces impending paradoxical embolism, which though proposed, is documented very rarely in live patients. This is a high-risk situation. Surgical embolectomy, like our case, has shown to have better outcomes in overall patient survival.

Case: A 66-year-old female with acute left main cerebral artery infarct and acute bilateral pulmonary embolism. In initial assessment, lower extremities venous Doppler study revealed left leg deep venous thrombosis and transthoracic echocardiogram showed a long biatrial clot straddling through patent foramen ovale and a right-to-left interatrial shunt. After heparinization and inferior vena caval filter placement, she underwent successful surgical embolectomy along with closure of patent foramen ovale with subsequent uneventful recovery.

Conclusion: 'Embolus in transit' is a high-risk situation and should be actively searched for in patients of pulmonary embolism and stroke. We recommend surgical embolectomy over other treatment modalities in such situations.

Keywords: Biatrial thrombus; Embolectomy; Paradoxical embolism; Patent foramen ovale; Pulmonary embolism; Stroke.

Figure 1

Transesophageal echocardiogram showing biatrial clot straddling through patent foramen ovale, the inferior end is prolapsing through the tricuspid valve into the RV. RA, right atrium; LA, left atrium; AO, aorta; RV, right ventricle.

Figure 2

An 18–20 cm clot was removed in one piece, which consists of two parts: a predominantly red clot of about 10 cm in the right atrium, and a 10 cm strand-like white clot extending across the septum into the left atrium.