Patent Foramen Ovale: A Fatal Trap

Abstract

A 39-year-old man referred to us with a complaint of dyspnea and palpitation of 3 days’ duration.  The patient was tachycardic but normotensive with a normal blood oxygen saturation level of about 91%. His electrocardiogram showed a sinus rhythm with an incomplete right bundle branch block. There was no known risk factor for vein thrombosis in his past medical history. Transthoracic and then transesophageal echocardiography revealed a large, hypermobile elongated mass (about 10×1 cm) in the right atrium. The mass was in transit through a large patent foramen ovale (Figure 1, Video 1). There was also severe right ventricular dilation with moderate systolic dysfunction on echocardiography, suggestive of pulmonary thromboembolism (PTE). Consequently, multiple-detector computed tomography angiography was performed to determine mortality risk and help the decision-making regarding the duration of anticoagulation therapy. The angiographic procedure revealed massive bilateral PTE (Figure 2).

The patient was referred for atriotomy and pulmonary embolectomy on cardiopulmonary bypass (Figure 3).

A thrombus in transit is a life-threatening, albeit rare, type of right-heart thrombosis with mortality rates of 80-100% in untreated patients,¹ necessitating urgent assessment and treatment. A thrombus in transit can result in catastrophic systemic embolism in a patient with PTE; therefore, taking heed of this issue in the presence of a right atrial mass is of great therapeutic significance. Meticulous imaging modalities in such patients are mandatory to prove the existence of a patent foramen ovale with a view to deciding on an emergent individualized therapeutic management of the patient’s condition.