Contrast transcranial Doppler ultrasound in the detection of right-to-left shunts: comparison of Echovist-200 and Echovist-300, timing of the Valsalva maneuver, and general recommendations for the performance of the test.
OBJECTIVE
Cardiac right-to-left shunts (RLS) can be identified by transesophageal echocardiography (TEE) as well as by transcranial Doppler ultrasound (TCD) using contrast agents, such as Echovist-200 or Echovist-300 in conjunction with a Valsalva maneuver (VM) as provocation procedure. Both Echovist preparations are in use. Currently, the appropriate timing of the VM is still under debate.


METHODS
Sixty-four patients were investigated by both TEE and bilateral TCD of the middle cerebral arteries. The following protocol was applied in a randomized way: (1) no VM, (2) VM for 5 s starting with the beginning of Echovist-300 injection, (3) VM for 5 s starting 5 s after the beginning of Echovist-300 injection, (4) VM for 5 s starting 10 s after the beginning of Echovist-300 injection, and (5) VM for 5 s starting 5 s after the beginning of Echovist-200 injection.


RESULTS
In 27 patients, an RLS was demonstrated by both TEE and contrast TCD (shunt-positive). Twenty-two patients were negative in both investigations, no patient was positive on TEE but negative on TCD, 15 patients were only positive on at least one TCD investigation but negative on TEE. Tests 3 and 5 were the most appropriate ones; test 3 was slightly superior to test 5.


CONCLUSIONS
TCD using Echovist-300 or Echovist-200 is a sensitive method to identify TEE-proven cardiac RLS. To achieve the best diagnostic accuracy, the VM should be performed for a duration of 5 s starting at 5 s following the beginning of contrast injection.
Droste
Dirk W
DW
Department of Neurology, University of Münster, Münster, Germany. droste2@uni-muenster.de
Jekentaite
Ruta
R
Stypmann
Jörg
J
Grude
Matthias
M
Hansberg
Tjark
T
Ritter
Martin
M
Nabavi
Darius
D
Nam
Eun-Mi
EM
Dittrich
Ralf
R
Wichter
Thomas
T
Ringelstein
E Bernd
EB
D000328:Adult; D000368:Aged; D002539:Cerebral Arterial Diseases / Q000150:complications / Q000175:diagnosis; D003287:Contrast Media; D017548:Echocardiography, Transesophageal; D019320:Embolism, Paradoxical / Q000150:complications / Q000175:diagnosis; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000150:complications / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D011134:Polysaccharides; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial; D014636:Valsalva Maneuver / Q000187:drug effects / Q000502:physiology
D003287:Contrast Media; D011134:Polysaccharides; C040642:SHU 454