Sensitivity of transcranial Doppler versus intracardiac echocardiography in the detection of right-to-left shunt.
OBJECTIVE
The purpose of this study was to understand the reason for variation in the sensitivity of different methods of detecting right-to-left shunts (RLS).


BACKGROUND
Patent foramen ovale (PFO) is implicated in the pathogenesis of cryptogenic stroke, decompression illness, and migraine headaches. Intravenous agitated saline injections with tomographic imaging (transthoracic, transesophageal, and intracardiac echocardiography) has been used for detecting intracardiac shunts. Some patients with a high clinical suspicion of PFO have inconclusive echocardiographic study results. Transcranial Doppler (TCD) is an alternative method for detecting RLS that is not dependent on tomographic imaging.


METHODS
Thirty-eight consecutive patients who were undergoing PFO closure had simultaneous transcranial Doppler and intracardiac echocardiography performed. Agitated saline injections were performed at rest, with Valsalva maneuver, and with forced expiration into a manometer to 40 mm Hg before and after closure, as well as 3 or more months after closure. Right atrial pressures were measured in the periprocedural period, and RLS were graded according to standard methods during these maneuvers.


RESULTS
Right atrial pressures were significantly higher with Valsalva maneuver compared with rest (before closure 21.6 +/- 11.9 mm Hg vs. 6.6 +/- 2.6 mm Hg, p < 0.001; after closure 28.4 +/- 13.9 mm Hg vs. 6.8 +/- 2.6 mm Hg, p < 0.001) and with manometer compared with Valsalva maneuver (before closure 38.7 +/- 6.6 mm Hg vs. 21.6 +/- 11.9 mm Hg, p < 0.001; after closure 44.0 +/- 9.5 mm Hg vs. 28.4 +/- 13.9 mm Hg, p < 0.001). Intracardiac echocardiography underestimated shunting in 34% of patients with Valsalva maneuver or manometer after closure compared with TCD.


CONCLUSIONS
Transcranial Doppler with immediate feedback provided by forced expiration against a manometer to 40 mm Hg is more sensitive than echocardiographic imaging for the detection of RLS. These observations have significant implications for determining the incidence of RLS in patients with stroke or migraine.
Van
HoHai
H
Division of Cardiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, USA.
Poommipanit
Paul
P
Shalaby
Mostafa
M
Gevorgyan
Rubine
R
Tseng
Chi-Hong
CH
Tobis
Jonathan
J
D000328:Adult; D000368:Aged; D016280:Atrial Function, Right; D006328:Cardiac Catheterization / Q000295:instrumentation; D002560:Cerebrovascular Circulation; D003326:Coronary Circulation; D017548:Echocardiography, Transesophageal; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011237:Predictive Value of Tests; D011312:Pressure; D055989:Septal Occluder Device; D012965:Sodium Chloride; D020521:Stroke / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial; D014636:Valsalva Maneuver
D012965:Sodium Chloride
Int J Cardiol. 2009 May 1;134(1):33-41
18715659
Circulation. 2008 Sep 30;118(14):1419-24
18794393
Stroke. 1991 Jun;22(6):740-5
2057972
N Engl J Med. 2001 Dec 13;345(24):1740-6
11742048
N Engl J Med. 1988 May 5;318(18):1148-52
3362165
J Neuroimaging. 2004 Oct;14(4):342-9
15358955
N Engl J Med. 2007 Nov 29;357(22):2262-8
18046029
Neurology. 2000 Oct 24;55(8):1172-9
11071496
Mayo Clin Proc. 1984 Jan;59(1):17-20
6694427
J Am Coll Cardiol. 1991 Jan;17(1):66-72
1987242
Radiology. 2002 Dec;225(3):693-9
12461247
Cerebrovasc Dis. 2002;13(2):102-6
11867883
Cerebrovasc Dis. 1998 Nov-Dec;8(6):327-30
9774749
J Am Soc Echocardiogr. 2006 Feb;19(2):215-22
16455428
J Am Coll Cardiol. 2005 Feb 15;45(4):489-92
15708691