Abstract 16784: Dynamic Change of Patent Foramen Ovale Area throughout Cardiac Cycle: A Real Time Three-Dimensional Transesophageal Echocardiographic Study

Abstract

Background: Patent foramen ovale (PFO) is a three-dimensional structure with dynamic change which makes it difficult to assess the morphology using two-dimensional (2D) methods. We aimed to assess geometry of PFO and change of PFO area throughout cardiac cycle using real time three-dimensional transesophageal echocardiography (RT3D TEE).

Methods: We studied 49 patients with PFO who underwent 2D and RT3D-TEE. The PFO area was measured at entrance (right atrium side), mid and exit (left atrium side) portion derived from longitudinal bicaval view at end diastole (QRS identified by ECG), early systole (aortic valve opening identified by RT3D-TEE), late systole (aortic valve closure), early and late diastole (Figure 1, 2).

Results: The shape of PFO was not circular but elongated in all patients (Vertical / Horizontal distance ratio: exit, 0.20±0.08, mid, 0.18±0.08, entrance, 0.18±0.10, Figure 1). Area of entrance was greater than that of exit at all the time except late systole (end diastole, 0.10±0.02 vs. 0.06±0.01 cm²,p=0.01;early systole, 0.18±0.02 vs. 0.08±0.01 cm², p<0.001; early diastole, 0.11±0.01 vs. 0.07±0.01 cm², p=0.01; late diastole, 0.11±0.02 vs. 0.06±0.01 cm², p=0.001; Figure 2). Furthermore, PFO area was largest at early systole in all portions. Especially, entrance area at early systole was significantly larger in a cardiac cycle (Figure 2).

Conclusion: RT3D-TEE could provide detailed and unique information of PFO morphology and dynamics.