P1-1 Detection of right-to-left shunts using transesophageal echocardiography and carotid duplex sonography, second report

The standard detection of right-to-left shunts (RLs) causing paradoxical embolism is based on transesophageal echo cardiology (TEE). However, it might be accompanied with risk for patients with esophageal varices, dysphagia or disturbance of consciousness. This study aimed to elucidate whether carotid ultrasonography (C-US) become alternative method for detecting RLs. Fifty-two patients were investigated by both TEE and C-US using micro-bubbles and they were performed with and without Valsalva maneuver (VM), respectively. We evaluated 52 acute cerebral infarctions. To measure Doppler waveform by C-US, sector-array probe was set in the internal carotid artery (ICA) of about 3cm above from ICA origin. RLs were evaluated for detecting air signals in the right atrium by the TEE, and micro-embolic signals (MES) in the ICA by C-US. Eleven RLs were proved by TEE, and even C-US were confirmed in 9 cases. The sensitivity and specificity using C-US were 82% and 90%, respectively. TEE is limited for the acute severe stroke,but C-US is easy to perform and has no contraindication.Our findings suggested MES using C-US are usefulness methods for assessment of RLs.