Document Detail


Differences in Ventilatory Inefficiency Between Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension.
MedLine Citation:
PMID:  21527511     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
ABSTRACT BACKGROUND: Measures of ventilatory efficiency during cardiopulmonary exercise testing (CPX) are increasingly being used as prognostic markers in heart failure and pulmonary hypertension (PH). Little is known about whether these measures can be applied to all forms of PH, in particular chronic thromboembolic pulmonary hypertension (CTEPH), where thrombotic vascular occlusion has an impact on gas exchange. METHODS AND RESULTS: 127 patients, 50 with CTEPH and 77 with pulmonary arterial hypertension (PAH), underwent incremental CPX. Physiological ventilatory deadspace fraction (V(D)/V(Tphys)) measured at peak exercise with arterial blood gas analysis was higher in CTEPH than PAH (52.9 vs 41.8, P<0.001). The V(E)/VCO(2) slope was higher in CTEPH patients than in PAH patients (50.7 vs. 44.4, p=0.024) and was mirrored by similar changes in the ventilatory equivalent for CO(2) at anerobic threshold (EqCO2_AT) (47.7 vs.42.0 p=0.008). In a multivariate linear regression analysis, disease subtype was found to be an independent predictor of V(D)/V(Tphys) (p<0.001), V(E)/VCO(2) slope (p=0.003) and EqCO2_AT (p<0.001). These three measures could distinguish between WHO functional classes I/II and III/IV in PAH, but not CTEPH. CONCLUSION: Significant differences in gas exchange exist between CTEPH and PAH, due to differences in V(D)/V(Tphys) likely as a result of vascular occlusion due to thromboembolic disease. This dissociates measures of ventilatory efficiency from disease severity and also contributes to our understanding of the differences in exercise limitation and breathlessness in PAH and CTEPH. Common prognostic end-points from CPX cannot be applied to all forms of PH.
Authors:
Zhenguo Zhai; Kevin Murphy; Hannah Tighe; Chen Wang; Martin R Wilkins; J Simon R Gibbs; Luke S Howard
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-4-28
Journal Detail:
Title:  Chest     Volume:  -     ISSN:  1931-3543     ISO Abbreviation:  -     Publication Date:  2011 Apr 
Date Detail:
Created Date:  2011-4-29     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0231335     Medline TA:  Chest     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
1Imperial College School of Medicine, Imperial College London, London, UK.
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