Lung function and stress echocardiography in pulmonary arterial hypertension
a cross-sectional study
Keywords:
Hypertension, pulmonary, Capnography, Respiratory function test, HypocapniaAbstract
BACKGROUND: The mechanism of exercise limitation in idiopathic pulmonary arterial hypertension (IPAH) is not fully understood. The role of hemodynamic alterations is well recognized, but mechanical, ventilatory and gasometric factors may also contribute to reduction of exercise capacity in these individuals. OBJECTIVE: To investigate whether there is an association between ventilatory pattern and stress Doppler echocardiography (SDE) variables in IPAH patients. DESIGN AND SETTING: Single-center prospective study conducted in a Brazilian university hospital. METHODS: We included 14 stable IPAH patients and 14 age and sex-matched controls. Volumetric capnography (VCap), spirometry, six-minute walk test and SDE were performed on both the patients and the control subjects. Arterial blood gases were collected only from the patients. The IPAH patients and control subjects were compared with regard to the abovementioned variables. RESULTS: The mean age of the patients was 38.4 years, and 78.6% were women. The patients showed hypocapnia, and in spirometry 42.9% presented forced vital capacity (FVC) below the lower limit of normality. In VCap, IPAH patients had higher respiratory rates (RR) and lower elimination of CO2 in each breath. There was a significant correlation between reduced FVC and the magnitude of increases in tricuspid regurgitation velocity (TRV). In IPAH patients, VCap showed similar tidal volumes and a higher RR, which at least partially explained the hypocapnia. CONCLUSIONS: The patients with IPAH showed hypocapnia, probably related to their higher respiratory rate with preserved tidal volumes; FVC was reduced and this reduction was positively correlated with cardiac output.
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References
Simonneau G, Montani D, Celermajer DS, et al. Haemodynamic definitions and updated clinical classification of pulmonary hypertension. Eur Respir J. 2019;53(1). pii: 1801913. PMID: 30545968; https://doi.org/10.1183/13993003.01913-2018
Modena DAO, Moreira MM, Paschoal IA, et al. Respiratory evaluation through volumetric capnography among grade III obese and eutrophic individuals: a comparative study. Sao Paulo Med J. 2019;137(2):177-83. PMID: 29340500; https://doi.org/10.1590/1516-3180.2017.0085011017
da Silva SM, Paschoal IA, De Capitani EM, et al. COPD phenotypes on computed tomography and its correlation with selected lung function variables in severe patients. Int J Chron Obstruct Pulmon Dis. 2016;11:503-13. PMID: 27042039; https://doi.org/10.2147/COPD.S90638
Pereira CAC. Diretrizes para Testes de Função Pulmonar. Jornal Brasileiro de Pneumologia. 2002;28(Supl 3). Available from: http://www.jornaldepneumologia.com.br/detalhe_suplemento.asp?id=45 Accessed in 2020 (Mar 27).
ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories. ATS Statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med. 2002;166(1):111-7. PMID: 12091180; https://doi.org/10.1164/ajrccm.166.1.at1102
Aduen JF, Castello R, Lozano MM, et al. An alternative echocardiographic method to estimate mean pulmonary artery pressure: diagnostic and clinical implications. 2009;22(7):814-9. PMID: 19505794; https://doi.org/10.1016/j.echo.2009.04.007
Huntsman LL, Stewart DK, Barnes SR, et al. Noninvasive doppler determination of cardiac output in man. Clinical validation. Circulation. 1983;67(3):593-602. PMID: 6821902; https://doi.org/10.1161/01.cir.67.3.593
Porter TR, Shillcutt SK, Adams MS, et al. Guidelines for the use of echocardiography as a monitor for therapeutic intervention in adults: a report from the American Society of Echocardiography. J Am Soc Echocardiogr. 2015;28(1):40-56. PMID: 25559474; https://doi.org/10.1016/j.echo.2014.09.009
Naeije R. Lung mechanics and exertional dyspnea in pulmonary arterial hypertension. Respiration. 2014;88(1):16-7. PMID: 24819832; https://doi.org/10.1159/000362171
Hoeper MM, Pletz MW, Golpon H, Welte T. Prognostic value of blood gas analyses in patients with idiopathic pulmonary arterial hypertension. Eur Respir J. 2007;29(5):944-50. PMID: 17301100; https://doi.org/10.1183/09031936.00134506
Richter MJ, Voswinckel R, Tiede H, et al. Dynamic hyperinflation during exercise in patients with precapillary pulmonary hypertension. Respir Med. 2012;106(2):308-13. PMID: 22100539; https://doi.org/10.1016/j.rmed.2011.10.018
Evans SA, Watson L, Cowley AJ, Johnston ID, Kinnear WJ. Static lung compliance in chronic heart failure: relation with dyspnoea and exercise capacity. Thorax. 1995;50(3):245-8. PMID: 7660336; https://doi.org/10.1136/thx.50.3.245
Laveneziana P, Garcia G, Joureau B, et al. Dynamic respiratory mechanics and exertional dyspnoea in pulmonary arterial hypertension. Eur Respir J. 2013;41(3):578-87. PMID: 22790921; https://doi.org/10.1183/09031936.00223611
Meyer FJ, Ewert R, Hoeper MM, et al. Peripheral airway obstruction in primary pulmonary hypertension. Thorax. 2002;57(6):473-6. PMID: 12037220; https://doi.org/10.1136/thorax.57.6.473
Richter MJ, Tiede H, Morty RE, et al. The prognostic significance of inspiratory capacity in pulmonary arterial hypertension. Respiration. 2014;88(1):24-30. PMID: 24852295; https://doi.org/10.1159/000360481
Laveneziana P, Humbert M, Godinas L, et al. Inspiratory muscle function, dynamic hyperinflation and exertional dyspnoea in pulmonary arterial hypertension. Eur Respir J. 2015;45(5):1495-8. PMID: 25931490; https://doi.org/10.1183/09031936.00153214
Grünig E, Tiede H, Enyimayew EO, et al. Assessment and prognostic relevance of right ventricular contractile reserve in patients with severe pulmonary hypertension. Circulation. 2013;128(18):2005-15. PMID: 24056689; https://doi.org/10.1161/CIRCULATIONAHA.113.001573
Yasunobu Y, Oudiz RJ, Sun XG, Wasserman K. End-tidal PCO2 abnormality and exercise limitation in patients with primary pulmonary hypertension. Chest. 2005;127(5):1637-46. PMID: 15888840; https://doi.org/10.1378/chest.127.5.1637
Hansen JE, Ulubay G, Chow BF, Sun XG, Wasserman K. Mixed-expired and end-tidal CO2 distinguish between ventilation and perfusion defects during exercise testing in patients with lung and heart diseases. Chest. 2007;132(3):977-83. PMID: 17573506; https://doi.org/10.1378/chest.07-0619
Oudiz RJ, Barst RJ, Hansen JE, et al. Cardiopulmonary exercise testing and six-minute walk correlations in pulmonary arterial hypertension. Am J Cardiol. 2006;97(1):123-6. PMID: 16377296; https://doi.org/10.1016/j.amjcard.2005.07.129
