title: Shunt volume dynamics in stroke patients with patent foramen ovale.
abstract: A variation in right atrial and pulmonary arterial pressure might result in a shunt dynamic across a patent foramen ovale (PFO). In the present study we tested if peak exercise facilitates a restoration of right to left shunt (RLS) in stroke patients who demonstrated a functional PFO closure (no evidence of RLS across an initially demonstrated PFO). In stroke patients with PFO demonstrating a functional closure, the RLS was reassessed on peak exercise using contrast-enhanced transcranial Doppler sonography. The exercise procedure consisted of a cardiopulmonary exercise test with supplementary stress echocardiography for assessment of pulmonary circulation. Four stroke patients with initially PFO curtain pattern and a subsequent functional PFO closure (no evidence for RLS) underwent the procedure. In all four patients a RLS could be resurrected during peak physical exercise after a Valsalva strain. While in two patients peak exercise led to an RLS in a countable range of microembolic signals, in two patients a curtain pattern was obtained. One patient showed evidence for reoccurrence of RLS on peak exercise without a Valsalva strain. The patients with curtain pattern had a better peak exercise performance. Although the systolic pulmonary arterial pressure increased during exercise in all patients, there was no direct correlation with the detected RLS. After a functional PFO closure peak exercise combined with a Valsalva strain facilitates the reoccurrence of RLS in stroke patients.
authors.affiliation: University Giessen Lung Center, University Hospital Giessen, Giessen, Germany;
authors.forename: F
authors.initials: F
authors.lastname: Reichenberger
authors.forename: M
authors.initials: M
authors.lastname: Kaps
authors.forename: W
authors.initials: W
authors.lastname: Seeger
authors.forename: C
authors.initials: C
authors.lastname: Tanislav
mesh_terms: D000328:Adult; D062186:Arterial Pressure / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005260:Female; D054092:Foramen Ovale, Patent / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000502:physiology; D011652:Pulmonary Circulation / Q000502:physiology; D020521:Stroke / Q000503:physiopathology*
keywords: Valsalva strain; cryptogenic stroke; patent foramen ovale; physical activity; pulmonary embolism; shunt dynamic