Safety of transcranial Doppler 'bubble study' for identification of right to left shunts: an international multicentre study.
OBJECTIVE
A recent retrospective study using an online list service established by the American Academy of Neurology has suggested that ischaemic cerebrovascular events may occur in patients who undergo 'bubble studies' (BS) with either transcranial Doppler (TCD) or transoesophageal echocardiography (TOE). The safety of TCD-BS for right to left shunt (RLS) identification was evaluated prospectively in an international multicentre study.


METHODS
Consecutive patients with cerebral ischaemia (ischaemic stroke or transient ischaemic attack (TIA)) were screened for potential ischaemic cerebrovascular events following injection of microbubbles during TCD-BS for identification of RLS at three tertiary care stroke centres. TCD-BS was performed according to the standardised International Consensus Protocol. TOE-BS was performed in selected cases for confirmation of TCD-BS.


RESULTS
508 patients hospitalised with acute cerebral ischaemia (mean age 46±12 years, 59% men; 63% ischaemic stroke, 37% TIA) were investigated with TCD-BS within 1 week of ictus. RLS was identified in 151 cases (30%). TOE-BS was performed in 101 out of 151 patients with RLS identified on TCD-BS (67%). It was positive in 99 patients (98%). The rate of ischaemic cerebrovascular complications during or after TCD-BS was 0% (95% CI by the adjusted Wald


METHODS
0-0.6%). Structural cardiac abnormalities were identified in 38 patients, including atrial septal aneurysm (n=23), tetralogy of Fallot (n=1), intracardiac thrombus (n=2), ventricular septal defect (n=3) and atrial myxoma (n=1).


CONCLUSIONS
TCD-BS is a safe screening test for identification of RLS, independent of the presence of cardiac structural abnormalities.
Department of Neurology, Democritus University of Thrace, School of Medicine, Alexandroupolis, Greece. tsivgoulisgiorg@yahoo.gr
Georgios
G
Tsivgoulis
Elefterios
E
Stamboulis
Vijay K
VK
Sharma
Ioannis
I
Heliopoulos
Konstantinos
K
Voumvourakis
Hock Luen
HL
Teoh
Konstantinos
K
Vadikolias
Nikos
N
Triantafyllou
Bernard P L
BP
Chan
Spyros N
SN
Vasdekis
Charitomeni
C
Piperidou
D000328:Adult; D002560:Cerebrovascular Circulation; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D007511:Ischemia / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002546:Ischemic Attack, Transient / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D061214:Patient Safety; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis* / Q000000981:diagnostic imaging; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*