Sensitivity of Transcranial Doppler Versus
Intracardiac Echocardiography in the
Detection of Right-to-Left Shunt
HoHai Van, MD,* Paul Poommipanit, MD,* Mostafa Shalaby, MD,*
Rubine Gevorgyan, MD,* Chi-Hong Tseng, PHD,† Jonathan Tobis, MD*
Los Angeles, California
O B J E C T I V E S 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).
B A C K G R O U N D 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.
M E T H O D S 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
R E S U L T S 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.
C O N C L U S I O N S 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. (J Am Coll Cardiol Img 2010;3:343–8) © 2010 by the American College of
From the *Division of Cardiology and the †Department of Medicine, David Geffen School of Medicine, University of
California at Los Angeles, Los Angeles, California. This study was funded by an unrestricted grant from AGA Medical, Inc.
Dr. Tobis is a consultant to AGA Medical, Inc., and is on the medical advisory board for the PREMIUM trial.
Manuscript received May 25, 2009; revised manuscript received November 19, 2009, accepted December 7, 2009.
J A C C : C A R D I O V A S C U L A R I M A G I N GV O L . 3 , N O . 4 , 2 0 1 0
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could have misplaced the subjects into the wrong
categories (14,15). A TCD evaluation performed
while bearing down against a calibrated manometer
seems to be more accurate than the other methods
to quantitate the size and presence of an RLS. This
also would be important in migraine studies, in
which a PFO could be treated by a device and yet a
small RLS could still exist through the device or the
pulmonary circulation and be missed by echocardi-
A TCD by itself does not reveal the anatomic
origin of the shunt. The shunt could be at the
pulmonary or cardiac level with a positive TCD.
However, the increased sensitivity of TCD suggests
that it would be the method of choice if the
question asked is: does the patient have an RLS?
The optimal assessment of an RLS would be a
TCD agitated saline–blood study in addition to an
anatomic assessment of the shunt by TEE or ICE.
Establishing the diagnosis of PFO is important for
understanding the mechanisms of certain diseases,
such as cryptogenic stroke and migraine. A TEE
may not be the optimal initial screening test for the
detection of PFO. In addition to avoiding the
discomfort of TEE, TCD during forced expiration
to 40 mm Hg into a manometer provides immedi-
ate feedback so that the patient is more likely to
achieve this atrial pressure. The result is that TCD
is more sensitive than tomographic imaging modal-
ities such as TTE, TEE, and ICE for detecting
Reprint requests and correspondence: Dr. Paul Poom-
mipanit, Department of Medicine, Division of Cardiol-
ogy, 650 Charles E. Young Drive South, Center for
Health Sciences A2-237, Los Angeles, California 90095.
R E F E R E N C E S
1. Lechat P, Mas JL, Lascault G, et al.
Prevalence of patent foramen ovale in
patients with stroke. N Engl J Med
2. Overell JR, Bone I, Lees KR. Inter-
atrial septal abnormalities and stroke:
a meta-analysis of case-control stud-
ies. Neurology 2000;55:1172–9.
3. Handke M, Harloff A, Olschewski M,
Hetzel A, Geibel A. Patent foramen
ovale and cryptogenic stroke in older
patients. N Engl J Med 2007;357:
4. Del Sette M, Angeli S, Leandri M, et
al. Migraine with aura and right-to-
left shunt on transcranial Doppler: a
case-control study. Cerebrovasc Dis
5. Sztajzel R, Genoud D, Roth S, Mer-
millod B, Le Floch-Rohr J. Patent
foramen ovale, a possible cause of
symptomatic migraine: a study of 74
patients with acute ischemic stroke.
Cerebrovasc Dis 2002;13:102–6.
6. Hagen PT, Scholz DG, Edwards
WD. Incidence and size of patent
foramen ovale during the first 10 de-
cades of life: an autopsy study of 965
normal hearts. Mayo Clin Proc 1984;
7. Pearson AC, Labovitz AJ, Tatineni S,
Gomez CR. Superiority of trans-
esophageal echocardiography in de-
tecting cardiac source of embolism in
patients with cerebral ischemia of un-
certain etiology. J Am Coll Cardiol
8. Teague SM, Sharma MK. Detection
of paradoxical cerebral echo contrast
embolization by transcranial Doppler
ultrasound. Stroke 1991;22:740–5.
9. Blersch WK, Draganski BM, Holmer
SR, et al. Transcranial duplex sonog-
raphy in the detection of patent fora-
men ovale. Radiology 2002;225:
10. Spencer MP, Moehring MA, Jesurum
J, Gray WA, Olsen JV, Reisman M.
Power M-mode transcranial Doppler
for diagnosis of patent foramen ovale
and assessing transcatheter closure.
J Neuroimaging 2004;14:342–9.
11. Azarbal B, Tobis J, Suh W, Chan V,
Dao C, Gaster R. Association of in-
teratrial shunts and migraine head-
aches: impact of transcatheter closure.
J Am Coll Cardiol 2005;45:489–92.
12. Woods TD, Patel A. A critical review
of patent foramen ovale detection us-
ing saline contrast echocardiography:
when bubbles lie. J Am Soc Echocar-
13. von Bardeleben RS, Richter C, Otto J,
et al. Long term follow up after per-
cutaneous closure of PFO in 357 pa-
tients with paradoxical embolism: dif-
ference in occlusion systems and
influence of atrial septal aneurysms.
Int J Cardiol 2009;134:33–41.
14. Mas JL, Arquizan C, Lamy C, et al.
Recurrent cerebrovascular events asso-
ciated with patent foramen ovale,
atrial septal aneurysm or both. N Engl
J Med 2001;345:1740–6.
15. Rundek T, Elkind MS, Di Tullio
MR, et al. Patent foramen ovale and
migraine: a cross-sectional study
from the Northern Manhattan Study
(NOMAS). Circulation 2008;118:
Key Words: patent foramen
ovale y transcranial Doppler y
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TCD Versus ICE for the Detection of Right-to-Left Shunt