Abstract 16788: Classification of Patent Foramen Ovale Tunnel Morphology; A Real Time 3-Dimentional Transesophageal Echocardiographic Study

Abstract

Background: Shape of patent foramen ovale (PFO) tunnel has been classified anatomically into 3 types by 2D-TEE. However, PFO morphology is 3-dimensional structure, which may be difficult to classify the type accurately by 2D-TEE.

Methods: We studied 49 patients with PFO who underwent 2D and real time 3-dimensional transesophageal echocardiography (RT3D-TEE). Tunnel type was classified based on the minimum overlap of septum primum (SP) and septum secundum (SS) under Valsalva maneuver with 3D-TEE images. Type 1 was defined as complete overlap, type 2 as partial overlap (≧ 4 mm) and type 3 as little or zero overlap (< 3 mm) (Figure 1). Furthermore, the number of shunt bubbles was counted in 3-D space and defined less than 9 as grade 1, 10 to 29 as grade 2 and more than 30 bubbles as grade 3.

Results: Type 1 was observed in 23 (46.9 %), type 2 in 4 (8.2 %) and type 3 in 22 (44.9 %) patients. Bubble grade 1 was observed in 8 (16.3 %), grade 2 in 15 (30.6 %) and grade 3 in 26 (53.1 %) patients. There was an association between tunnel type and bubble grade (p=0.041, Figure 2). Furthermore, there was an association between tunnel type and cerebral event (p=0.035, Figure 2).

Conclusion: RT3D-TEE could provide accurate information of PFO morphology and may be useful to clarify high risk patients with PFO.