RESUMO
BACKGROUND: The aim of this study was to determine the frequency of extracardial and particularly pulmonal right-to-left-shunts (RLS) in patients with acute cerebral ischemia of unknown origin. PATIENTS AND METHODS: We investigated 52 patients under 60 years of age with cerebral ischemic stroke of unknown origin using transesophageal echocardiography (TEE) with special attention to the late phase of ultrasound contrast medium in the left atrium. Additionally we performed contrast transcranial doppler sonography (TCD). RESULTS: In the TEE, 25 patients (48%) showed cardial RLS. In seven patients with normal TEE (13.5%) we found evidence of RLS with contrast TCD (spontaneous RLS n=4, RLS after valsalva n=3). In none of these seven patients did we find late-phase contrast in the left atrium. CONCLUSION: The constellation of RLS detection in contrast TCD but not in TEE was frequently found. Particularly in spontaneous RLS, this constellation raises the suspicion of a pulmonary shunt. However our extended TEE protocol did not give additional evidence for a pulmonary location of the shunt.
