title: Exercise stress echocardiography of the pulmonary circulation: limits of normal and sex differences.
abstract: BACKGROUND
  Exercise stress echocardiography has not been recommended in the diagnostic workup of pulmonary hypertension because of insufficient certainty about feasibility and limits of normal.
  
  
  METHODS
  Doppler echocardiography pulmonary hemodynamic measurements were performed at a progressively increased workload in 56 healthy male and 57 healthy female volunteers aged 19 to 63 years. Mean pulmonary artery pressure (mPAP) was estimated from the maximal tricuspid regurgitation jet velocity. Cardiac index was calculated from the left ventricular outflow velocity-time integral. Pulmonary vascular distensibility a index, the percentage change of vessel diameter permm Hg of mPAP, was calculated from multipoint mPAP-cardiac output (CO) plots.
  
  
  RESULTS
  Peak exercise at 175 ±50 W was associated with an mPAP of 33±7 mm Hg and a CO of 18 ±5 L/min. The slope of mPAP-CO relationships was 1.5 ± 0.5 mm Hg/L/min, and the distensibility coefficient ( α ) was 1.3%± 1.0%/mm Hg. Maximal workload and cardiac index were higher in men than in women ( P , .05), but mPAP-cardiac index relationships were not different. However,women had a higher a (1.6%± 1.3%/mm Hg vs 1.1%± 0.6%/mm Hg, P < .05). The average mPAP-cardiac index slope was higher and a lower in subjects ≥50 years old. Upper limits of normal of mPAP at exercise were 34 mm Hg at a CO , 10 L/min, 45 mm Hg at a CO <20 L/min, and 52 mm Hg at a CO<30 L/min. These values are in keeping with previously reported invasive measurements.
  
  
  CONCLUSIONS
  Exercise stress echocardiography of the pulmonary circulation is feasible and allows for fl ow-corrected definition of upper limits of normal. Women have a more distensible pulmonary circulation.
authors.affiliation: Department of Cardiology, Second University of Naples, Naples, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Argiento
authors.affiliation: Department of Physiology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium.
authors.forename: Rebecca R
authors.initials: RR
authors.lastname: Vanderpool
authors.affiliation: Clinical Division of Cardiology, Ferrarotto Hospital, University of Catania, Catania, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Mulè
authors.affiliation: Department of Cardiology, Second University of Naples, Naples, Italy.
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Russo
authors.affiliation: Department of Cardiology, Second University of Naples, Naples, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: D'Alto
authors.affiliation: Department of Cardiac Surgery, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bossone
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI.
authors.forename: Naomi C
authors.initials: NC
authors.lastname: Chesler
authors.affiliation: Department of Physiology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium. Electronic address: rnaeije@ulb.ac.be.
authors.forename: Robert
authors.initials: R
authors.lastname: Naeije
mesh_terms: D000328:Adult; D025401:Echocardiography, Stress; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation / Q000502:physiology*; D012016:Reference Values; D012737:Sex Factors