Abstract 14878: Be Aware of False Negative Bubble Study in Diagnosis of Patent Foramen Ovale!

Abstract

Introduction: Echocardiography plays an important role in diagnosis of Patent Foramen Ovale (PFO). However, there are some anatomic variations which may result in a false negative study. Case presentation: A 55-year-old male was hospitalized for acute right-hemiplegia. The EKG revealed normal sinus rhythm. Brain imaging revealed acute bilateral infarcts. The transthoracic echocardiogram (TTE) showed a normal ejection fraction without significant valve disease and a negative agitated saline Bubble study. A Trans-esophageal echocardiogram (TEE) revealed a negative Bubble study using intravenous access via the left arm. The TEE also revealed an atrial septal aneurysm and large eustachian valve (EV). The Bubble study was then repeated with agitated saline injected from lower extremity. This demonstrated a significant right to left shunt through a PFO. Discussion: EV is a remnant of the valve of the inferior vena cava that directs blood flow through the fossa ovalis during embryonic life. A large or prominent EV may be a risk factor for paradoxical embolism by preventing spontaneous foramen closure. Agitated saline originating from the superior vena cava (SVC) may result in a false-negative study due to the prominent EV preventing microbubbles from the SVC from crossing the interatrial septum. In this case, the patient’s age, clinical presentation and the finding of EV and atrial septal aneurysm raised the suspicion of PFO. Repeating the bubble study using a lower extremity peripheral access was positive. This step played a crucial role in the diagnosis of PFO in this patient and his subsequent management. Conclusion: Cardiologists should be aware that the presence of a prominent EV may result in a false negative bubble study result when the injection is performed via upper limb intravenous access.