Submaximal Exercise Pulmonary Gas Exchange in Left Heart Disease Patients with Different Forms of Pulmonary Hypertension

Bryan J. Taylor, Michael R. Smetana, Robert Frantz, Bruce David Johnson

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Background We determined whether pulmonary gas exchange indices during submaximal exercise are different in heart failure (HF) patients with combined post- and pre-capillary pulmonary hypertension (PPC-PH) versus HF patients with isolated post-capillary PH (IPC-PH) or no PH. Methods and Results Pulmonary hemodynamics and pulmonary gas exchange were assessed during rest and submaximal exercise in 39 HF patients undergoing right heart catheterization. After hemodynamic evaluation, patients were classified as having no PH (n = 11), IPC-PH (n = 12), or PPC-PH (n = 16). At an equivalent oxygen consumption, end-tidal CO<inf>2</inf> (PETCO<inf>2</inf>) and arterial oxygen saturation (SaO<inf>2</inf>) were greater in no-PH and IPC-PH versus PPC-PH patients (36.1 ± 3.2 vs 31.7 ± 4.5 vs 26.2 ± 4.7 mm Hg and 97 ± 2 vs 96 ± 3 vs 91 ± 1%, respectively). Conversely, dead-space ventilation (V<inf>D</inf>/V<inf>T</inf>) and the ventilatory equivalent for carbon dioxide (V<inf>E</inf>/VCO<inf>2</inf>ratio) were lower in no-PH and IPC-PH versus PPC-PH patients (0.37 ± 0.05 vs 0.38 ± 0.04 vs 0.47 ± 0.03 and 38 ± 5 vs 42 ± 8 vs 51 ± 8, respectively). The exercise-induced change in V<inf>D</inf>/V<inf>T</inf>, V<inf>E</inf>/VCO<inf>2</inf> ratio, and PETCO<inf>2</inf> correlated significantly with the change in mean pulmonary arterial pressure, diastolic pressure difference, and transpulmonary pressure gradient in PPC-PH patients only. Conclusions Noninvasive pulmonary gas exchange indices during submaximal exercise are different in HF patients with combined post- and pre-capillary PH compared with patients with isolated post-capillary PH or no PH.

Original languageEnglish (US)
Pages (from-to)647-655
Number of pages9
JournalJournal of Cardiac Failure
Volume21
Issue number8
DOIs
StatePublished - Aug 1 2015

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Keywords

  • Diastolic pressure difference
  • pre- and post-capillary pulmonary hypertension
  • right-heart catheterization
  • submaximal exercise

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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