PATENT FORAMEN OVALE SIZE AND POTENTIAL CARDIOVASCULAR EMBOLIC RISK -BIPLANAR TRANSESOPHAGEAL ECHOCARDIOGRAPHIC STUDY

The goal of the study was to assess the ability of transesophageal ech ocardiographic (TEE) longitudinal (l) and horizontal (h) planes (pl) i n detecting and sizing patent foramen ovale (PFO) and in identifying s ubgroups of patients (pts) with PFO at risk of embolic events (E). Our study group was composed of 180 patients referred to our institutions for clinical suspicion of cardiac source of emboli without atheroscle rotic plaques in epiaortic arteries by echography. All patients underw ent biplane TEE contrast (c) examination. Hemagel, injected into an up per arm vein, was used as contrast medium. A contrast study was consid ered positive if at least two clearly seen targets, confirmed by two o bservers, appear in the left atrium within three cardiac cycles. Stati stical analysis was performed by Student's t test and by linear regres sion. Thirty-six out of 180 patients had a positive study for PFO. The actual opening of PFO was visualized in 21/36 patients by 1 pl and in 1/36 patients by h pl. The diameter of the PFO opening (OF) ranged fr om 2 to 10 mm, mean 5.85 +/- 2.23; 11/21 patients had previous E. PFO OP ranged from 4 to 10 mm, mean 6.9 +/- 1.97, in patients with E and f rom 2 to 8 mm, mean 4.8 +/- 2.04, in patients without E (p < 0.03). A meaningful correlation between the number of microbubbles and the PFO dimensions was found too (r = 0.71; p < 0.001). The diameter PFO OP wa s larger in patients with E; this observation suggests that only large r PFO may act as a conduct for paradoxical embolism. TEE v pl is able to visualize and size PFO OF. The ability to size PFO OP might help in identifying subgroups of patients at high risk of E. Further studies are needed to confirm this hypothesis.