Controlled Contrast Transcranial Doppler and Arterial Blood Gas Analysis to Quantify Shunt Through Patent Foramen Ovale

Gérald Devuyst, Bartłomiej Piechowski-Jóźwiak, Theodoros Karapanayiotides, Jean William Fitting, Vendel Kémeny, Lorenz Hirt, Luis A. Urbano, Pierre Arnold, Guy Van Melle, Paul Andre Despland, Julien Bogousslavsky

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34 Citations (Scopus)


Background and Purpose-A right-to-left shunt can be identified by contrast transcranial Doppler ultrasonography (c-TCD) at rest and/or after a Valsalva maneuver (VM) or by arterial blood gas (ABG) measurement. We assessed the influence of controlled strain pressures and durations during VM on the right-to-left passage of microbubbles, on which depends the shunt classification by c-TCD, and correlated it with the right-to-left shunt evaluation by ABG measurements in stroke patients with patent foramen ovale (PFO). Methods-We evaluated 40 stroke patients with transesophageal echocardiography-documented PFO. The microbubbles were recorded with TCD at rest and after 4 different VM conditions with controlled duration and target strain pressures (duration in seconds and pressure in cm H2O, respectively): V5-20, V 10-20, V5-40, and V 10-40. The ABG analysis was performed after pure oxygen breathing in 34 patients, and the shunt was calculated as percentage of cardiac output. Results-Among all VM conditions, V5-40 and V 10-40 yielded the greatest median number of microbubbles (84 and 95, respectively; P<0.01). A significantly larger number of microbubbles were detected in V5-40 than in V5-20 (P<0.001) and in V10-40 than in V10-20 (P<0.01). ABG was not sensitive enough to detect a shunt in 31 patients. Conclusions-The increase of VM expiratory pressure magnifies the number of microbubbles irrespective of the strain duration. Because the right-to-left shunt classification in PFO is based on the number of microbubbles, a controlled VM pressure is advised for a reproducible shunt assessment. The ABG measurement is not sensitive enough for shunt assessment in stroke patients with PFO.

Original languageEnglish
Pages (from-to)859-863
Number of pages5
Issue number4
Publication statusPublished - Apr 1 2004



  • Foramen ovale, patent
  • Oxygen
  • Ultrasonography, Doppler, transcranial
  • Valsalva maneuver

ASJC Scopus subject areas

  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine
  • Advanced and Specialised Nursing

Cite this

Devuyst, G., Piechowski-Jóźwiak, B., Karapanayiotides, T., Fitting, J. W., Kémeny, V., Hirt, L., Urbano, L. A., Arnold, P., Van Melle, G., Despland, P. A., & Bogousslavsky, J. (2004). Controlled Contrast Transcranial Doppler and Arterial Blood Gas Analysis to Quantify Shunt Through Patent Foramen Ovale. Stroke, 35(4), 859-863.