Dynamic PFO Shunting In Cryptogenic Stroke: ICE Resolves TEE Diagnostic Discrepancy

The above images were obtained during the work-up of recurrent cryptogenic ischemic stroke in an elderly patient. The electrocardiogram (EKG, Figure A) revealed sinus rhythm, right axis deviation, low voltage throughout and nonspecific T wave abnormalities. Transthoracic echocardiography image (TTE, Figure B) with bubble study in the apical 4-chamber view revealed right-to-left shunting suggestive of a patent foramen ovale (PFO). Transesophageal echocardiography (TEE, Figure C) however showed no shunting, likely due to pressure gradient dynamics favoring left atrial dominance during the procedure with inadequate Valsalva maneuver due to sedation. Intracardiac echocardiography (ICE, Figure D) during PFO closure preparation confirmed an intermittently shunting PFO tunnel, opening only when right atrial pressure exceeded left atrial pressure. The PFO was successfully closed percutaneously with a 30-mm Cardioform PFO occlude device, with no residual shunt by ICE.