Inferior Vena Cava Compression as a Novel Maneuver to Detect Patent Foramen Ovale: A Transesophageal Echocardiographic Study

Background The Valsalva maneuver, the most sensitive test for patent foramen ovale (PFO) detection, is difficult during transesophageal echocardiography (TEE), especially after sedation. The aim of this study was to compare PFO detection effectiveness between inferior vena cava (IVC) compression and the Valsalva maneuver. Methods A total of 293 patients with paroxysmal atrial fibrillation undergoing TEE before initial atrial fibrillation ablation were prospectively enrolled. Agitated saline was injected in 290 patients under three conditions: Valsalva maneuver under conscious sedation, at rest, and IVC compression under deep sedation. Three patients with newly diagnosed atrial septal defects on TEE were excluded. The IVC compression maneuver consisted of manual compression 5 cm to the right of the epigastric region and depressed the abdominal wall by 5 cm for 30 sec and compression release immediately before right atrial opacification with microbubbles by agitated intravenous saline. Results The overall PFO detection rate was better with IVC compression (57 PFOs [19.7%]) than at rest (15 patients [5.2%]) ( P P  = .024). There were no significant differences in PFO detection between IVC compression and the Valsalva maneuver (IVC compression, 43 patients [22.5%]; Valsalva maneuver, 35 patients [18.3%]; P  = .31), even in patients who could perform the Valsalva maneuver effectively ( n  = 191). Conclusions IVC compression is feasible and effective for detecting PFO and is not inferior to the Valsalva maneuver. In particular, IVC compression could be an alternative diagnostic method for PFO using TEE when the Valsalva maneuver cannot be performed under deep sedation.