A comparison of transesophageal echocardiography and transcranial Doppler sonography with contrast medium for detection of patent foramen ovale.

BACKGROUND: Patent foramen ovale as a possible stroke risk factor can be diagnosed with transcranial Doppler sonography (TCD) by detecting intravenous contrast medium crossing from the right to the left atrium. The present study evaluates the reliability of this method. SUMMARY OF REPORT: We performed TCD and transesophageal echocardiography simultaneously in 50 patients using galactose microbubbles. We observed bubble signals passing the middle cerebral artery in 7 patients less than 20 seconds after injection; we found positive TCD tests in 14 patients using the Valsalva maneuver. With transesophageal echocardiography patent foramen ovale could be detected in 15 patients (sensitivity, 0.93; specificity, 1; P < .01).
CONCLUSIONS: TCD with echo contrast is a reliable screening tool for patent foramen ovale. A standardized procedure including the Valsalva maneuver is essential to prevent false-negative results.