Résumé : ABSTRACT BACKGROUND:Exercise stress echocardiography has not been recommended in the diagnostic work-up of pulmonary hypertension, because of insufficient certainty about feasibility and limits of normal. METHODS:Doppler echocardiography pulmonary hemodynamic measurements were performed at progressively increased workload in 56 healthy male and 57 healthy female volunteers aged 19-63 yrs. Mean pulmonary artery pressure (mPAP) was estimated from the maximum tricuspid regurgitation jet velocity. Cardiac Index (CI) was calculated from the left ventricular outflow velocity-time integral. Pulmonary vascular distensibility α-index, the % change of vessel diameter per mmHg of mPAP, was calculated from multi-point mPAP-cardiac output (CO) plots. RESULTS:Peak exercise at 175 ± 50 W was associated with mPAP of 33 ± 7 mmHg and CO of 18 ± 5 L/min. The slope of mPAP-CO relationships was 1.5 ± 0.5 mmHg/L/min, and α was 1.3 ± 1.0 %/mmHg. Maximum workload and CI were higher in men than in women (p<0.05), but mPAP-CI relationships were not different. However, women had a higher α (1.6 ± 1.3 vs 1.1 ± 0.6 %/mmHg; p<0.05). Average mPAP-CI slope was higher and α lower in subjects >50 years. Upper limits of normal of mPAP at exercise were 34 mmHg at a CO<10 L/min, 45 mmHg at a CO<20 L/min and 52 mmHg 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 flow-corrected definition of upper limits of normal. Women have a more distensible pulmonary circulation.