Abstract W P190: Contrast Transcranial Doppler Detects More Intra and Extra-Cardiac Right-to-Left Shunts than Trans-Esophageal Echocardiogram

Abstract

INTRODUCTION/OBJECTIVES: Paradoxical embolism is initially evaluated with a contrast trans-thoracic echocardiogram (cTTE), since the more sensitive method of contrast trans-esophageal echocardiogram (cTEE) is also more invasive. An adequate valsalva is essential to raise intra-thoracic pressures, but since the patient is sedated for the procedure, it is not always possible with cTEE. The amount of RLS through a PFO depends on strain rate and duration of the Valsalva maneuver. CTCD is a non-invasive method of detecting RLS that has been shown to be as good as cTEE. The goal of this study was to evaluate whether or not cTCD could be more effective at detecting RLS. MATERIALS AND METHODS: A review and evaluation of medical records and imaging was done on patients with embolic stroke from 2012-2013 at a university affiliated comprehensive stroke center. Patients had embolic stroke and a cTCD to be included. A subgroup of patients who had cTCD also had a cTEE. Patients who were positive for RLS on cTCD were compared with those who had RLS on cTEE. Statistical analysis was performed to determine significance and potential for future complications. RESULTS: A total of 1,033 patient records were reviewed and of those 130 patients (55% women) had embolic stroke and a cTCD, 35 were positive for a RLS based on the presence of microbubbles in the cerebral circulation, and 95 were negative. Of the 35 patients with positive cTCD, 45% (n=16) also underwent cTEE; however, only 44% (n=7) of those had positive results for RLS. Conversely, 56% (n=9) of the patients who were shown to have RLS on cTCD were missed on cTEE (without cardiac septal defects). Of the 95 patients who had negative cTCD, 19 of them also underwent cTEE and all were negative on cTEE. CONCLUSION: Using cTCD to detect microbubbles in cerebral arteries appears to be more reliable and accurate for discovering RLS of intra or extra-cardiac origin. For embolic ischemic strokes, we recommend using cTCD as a first-line study and suggest it should be the new “gold standard”. Randomized, prospective studies should be conducted to further validate this data.