This Article Full Text Full Text (PDF) All Versions of this Article: 39/8/2380    most recent STROKEAHA.107.509331v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Caputi, L. Articles by Anzola, G. P. Search for Related Content PubMed PubMed Citation Articles by Caputi, L. Articles by Anzola, G. P. Pubmed/NCBI databases Medline Plus Health Information Stroke Related Collections Echocardiography Embolic stroke Doppler ultrasound, Transcranial Doppler etc.

(Stroke. 2008;39:2380.)
© 2008 American Heart Association, Inc.

Research Letters

Postural Dependency of Right to Left Shunt

Role of Contrast-Enhanced Transcranial Doppler and Its Potential Clinical Implications

Luigi Caputi, MD; Maria R. Carriero, MD; Eugenio A. Parati, MD; Eustaquio Onorato, MD; Francesco Casilli, MD; Marco Berti Gian Paolo Anzola, MD

From the Department of Cerebrovascular Diseases (L.C., M.R.C., E.A.P.), National Neurological Institute C. Besta, Milan, Italy; and the Department of Interventional Cardiology (E.O, F.C., M.B.) and the Service of Neurology (G.P.A.), S. Orsola Hospital FBF, Brescia, Italy.

Correspondence to Gian Paolo Anzola, MD, Service of Neurology, S. Orsola Hospital FBF, Via Vittorio Emanuele II, 27, 25100 Brescia, Italy. E-mail gpanzola{at}numerica.it

Background and Purpose— Right to left shunt is involved in conditions in which postural changes may be pathogenically relevant. The aim of this work was to assess the frequency of posturally dependent right to left shunt.

Methods— In 109 consecutive right to left shunt-positive subjects (male/female=40/69, age 43±12 years), we assessed with contrast-enhanced transcranial Doppler the bubble load during normal breathing and after the Valsalva maneuver in both standing and recumbent position randomizing the order of testing.

Results— During normal breathing, the average bubble count was 11±20 in the recumbent and 26±60 in the standing position. After the Valsalva maneuver, it was 40±38 and 42±37, respectively. The increase of bubble load in standing position occurred in 42% of patients and was independent of the order of testing.

Conclusions— The amount of permanent right to left shunt is posture-dependent in 40% of patients. Testing in the sitting position may thus be warranted in doubtful or inconclusive results obtained with the subject in the horizontal position.

Key Words: right to left shunt • transcranial Doppler • recumbent position • standing position

This article has been cited by other articles:

				G. Tsivgoulis, V. K. Sharma, and A. V. Alexandrov Detection of Right-to-Left Shunt With Transcranial Doppler Is Affected by Body-Positioning Stroke, November 1, 2008; 39(11): e184 - e184. [Full Text] [PDF]