FORAMEN OVALE AND IMPAIRED PULMONARY GAS EXCHANGE EFFICIENCY AT REST AND DURING EXERCISE: SIZE MATTERS

Authors

T Kelly
K Carey
J Elliot
RC Roach
AT Lovering

Abstract

T. Kelly¹, K. Carey¹, J. Elliot^2,3, R.C. Roach⁴, A.T. Lovering¹

¹University of Oregon, Eugene, OR; ²Oregon Health Science University, Portland, OR; ³ORVA Oregon Health Care System, Portland, OR; ⁴UC Denver Anschutz Medical Campus, Denver, CO

The patent foramen ovale (PFO) is a source of right-to-left intracardiac shunt. Previous studies have not studied the association of PFO size on pulmonary gas exchange efficiency at rest and during exercise. PURPOSE: To quantify differences in pulmonary gas exchange efficiency between individuals with a large PFO and those with a small PFO and/or no PFO. METHODS: 25 subjects (7 large PFO, 5 small PFO and 13 no PFO) were recruited and screened for presence and size of PFO utilizing saline contrast echocardiography. Large PFO was defined as Grade 3, small PFO as ≤Grade 2 and no PFO as absence of saline contrast bubbles. Subjects exercised at 5 submaximal workloads (70-190 Watts). Arterial blood was taken from a radial arterial catheter pre-exercise and during the final 30 seconds of each workload and immediately analyzed for pH, PaCO₂and PaO₂. Alveolar PO₂was calculated using the alveolar gas equation and the alveolar-to-arterial oxygen difference (gold standard measure of pulmonary gas exchange efficiency) was quantified. Comparisons were made using a 2 way ANOVA (group x time) with Bonferroni correction for pairwise comparisons, with significance set at pRESULTS: The presence of large PFO was associated with significantly decreased pulmonary gas exchange efficiency, compared to those subjects with a small PFO and no PFO with a specific pairwise difference at 160W (19.0 ± 2.8 vs 10.7 ±1.6; (mean ± SEM)). CONCLUSION: The presence of a large PFO is associated with impaired pulmonary gas exchange efficiency pre-exercise and during moderate sub-maximal workloads.

Support: American Heart Association (A.T. Lovering); Department of Defense (W81XWH-11-2-0040 TATRC to R.C. Roach and W81XWH-10-2-0114 to A.T. Lovering).

Recommended Citation

Kelly, T; Carey, K; Elliot, J; Roach, RC; and Lovering, AT (2019) "FORAMEN OVALE AND IMPAIRED PULMONARY GAS EXCHANGE EFFICIENCY AT REST AND DURING EXERCISE: SIZE MATTERS," International Journal of Exercise Science: Conference Proceedings: Vol. 8: Iss. 7, Article 11.
Available at: https://digitalcommons.wku.edu/ijesab/vol8/iss7/11