Chest
Volume 142, Issue 5, November 2012, Pages 1158-1165
Journal home page for Chest

Original Research
Pulmonary Vascular Disease
Exercise Stress Echocardiography of the Pulmonary Circulation: Limits of Normal and Sex Differences

https://doi.org/10.1378/chest.12-0071Get rights and content

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 α index, the percentage change of vessel diameter per mm 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 α (1.6% ± 1.3%/mm Hg vs 1.1% ± 0.6%/mm Hg, P < .05). The average mPAP-cardiac index slope was higher and α 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 flow-corrected definition of upper limits of normal. Women have a more distensible pulmonary circulation.

Section snippets

Materials and Methods

One hundred twenty-four volunteers (62 women and 62 men) aged 37 ± 13 years (range, 18-63 years) with a height and weight of 173 ± 9 cm and 70 ± 11 kg, respectively (body surface area, 1.8 ± 0.2) gave an informed consent to the study, which was approved by the ethical committee of the Erasme University Hospital (No. P2011/101; Ref. Eudract/CCB: B406201110799, Brussels, Belgium). The subjects were nonsmokers and were free of any cardiovascular or lung disease. None had a family history of

Results

Good-quality signals were available at all levels of exercise in all subjects. Because 11 subjects had been excluded at an initial echocardiographic evaluation, this corresponds to an 87% recovery rate of a complete exercise stress echocardiography of the pulmonary circulation in healthy adults.

Discussion

The results show that the upper limits of normal for mPAP at stress echocardiography depend on the achieved maximal CO. The previously used cut-off value of 30 mm Hg for the diagnosis of exercise-induced pulmonary hypertension is accurate for a CO below 8 to 10 L/min. Higher upper limits of normal for exercise mPAP, up to 50 mm Hg, are to be considered for higher COs achieved by fit healthy subjects. The results also show, we believe for the first time, that there are no sex differences in PVR,

Acknowledgments

Author contributions: Dr Argiento: contributed to the original design and concept of the study, data acquisition, data analysis, and preparation and critical review of the manuscript.

Dr Vanderpool: contributed to the analysis and interpretation of data and preparation and critical review of the manuscript.

Dr Mulè: contributed to the data acquisition, data analysis, review of echocardiographic images, and critical review of the manuscript.

Dr Russo: contributed to the concept of the study and

References (25)

  • G Kovacs et al.

    Pulmonary arterial pressure during rest and exercise in healthy subjects: a systematic review

    Eur Respir J

    (2009)
  • JJ Tolle et al.

    Exercise-induced pulmonary arterial hypertension

    Circulation

    (2008)
  • Cited by (135)

    View all citing articles on Scopus

    Funding/Support: This work was supported by the National Institutes of Health [1R01HL105598 to NCC], the Funds for Cardiac Surgery [to R. N.], the Fonds de la Recherche Scientifique Médicale [3.4637.09 to R. N.], and the Bureau for International Relations and Cooperation [to R. R. V.].

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.

    Drs Argiento and Vanderpool contributed equally to this article.

    View full text