Enhanced detection of patent foramen ovale by systematic transthoracic saline contrast echocardiography

ObjectiveWe aimed to evaluate the effectiveness of transthoracic saline contrast echocardiography (TSCE) in detecting patent foramen ovale (PFO).BackgroundTransesophageal echocardiography (TEE) is semi-invasive and not ideal for PFO screening.Methods112 patients (48 males, 46 ± 14 years) with suspected PFO received intravenous agitated-saline contrast at rest and stress (strain and release phases of Valsalva maneuver and coughing). The presence of interatrial shunting was defined as > 5 bubbles appearing in the left heart within 3 cardiac cycles. The stage of the maneuver at which interatrial shunting occurred was recorded. The TSCE findings were validated by TEE.ResultsTEE identified PFO in 45% of patients. The sensitivities of TSCE in detecting PFO at rest, during strain and release of Valsalva maneuver, and coughing were 12.0%, 38.0%, 80.0% and 94.0% respectively (each p < 0.05 when compared to previous stage). Specificities were similar and > 95% for all stages. Moreover, the release phase of the maneuver improved the diagnostic accuracy [defined as (number of true positives + true negatives) divided by total in sample] with incremental value over the preceding strain phase (89.2 vs. 70.5%, p < 0.001).ConclusionsPatent foramen ovale can be identified confidently with proper conduct of the Valsalva maneuver during the transthoracic saline contrast echocardiography.