Transesophageal echocardiography for quantifying size of patent foramen ovale in patients with cryptogenic cerebrovascular events

Background and Purpose-Patent foramen ovale (PFO) is a risk factor for paradoxical embolism, and severe shunting and wide opening of PFO are risk factors for severe and recurrent cerebrovascular events. Neither contrast echocardiography nor 2-dimensional (2D) measurement of PFO size have been validated or compared with invasive balloon sizing. Methods-We performed transesophageal echocardiography (TEE) in 100 patients with cryptogenic stroke and catheter closure of PFO. The amount of contrast shunting through the PFO during cubital and femoral contrast delivery and the PFO size measured by 2D TEE were compared with balloon sizing. Results-There was a significant correlation (r(2)=0.8; P<0.0001) between 2D TEE measurement and invasive balloon sizing. Mean balloon-sized PFO diameter was significantly larger than mean PFO diameter measured by 2D TEE (8.3 +/- 2.6 versus 5.2 +/- 1.7 mm). Semiquantitative contrast TEE correlated with PFO size (r(2)=0.7; P<0.0001) only if the contrast agent was administered through a femoral vein. Correlation was poor when the contrast agent was administered via a cubital vein. Conclusions-We conclude that 2D TEE measurement of a PFO size is more accurate than the traditionally used contrast technique.