Lower Diffusing Capacity of the Lungs for Carbon Monoxide in Women with a Patent Foramen Ovale
Abstract
The test of diffusing capacity of the lungs for carbon monoxide (DLco) assumes that all of the cardiac output flows through the pulmonary circuit. Right to left blood flow across a patent foramen ovale (PFO) allows blood to bypass the pulmonary circuit. The shunted red blood cells are not exposed to alveolar gas and thus, would not bind any carbon monoxide with a DLco test. This may result in a lower carbon monoxide uptake and therefore a lower measured DLco. Consequently, we hypothesized that subjects with a PFO (PFO+) would have a lower DLco than subjects without a PFO (PFO−). We retrospectively analyzed historical data from our lab that included 77 PFO+ subjects (Ages:18–35; 31 Female) and 55 PFO− subjects (Ages 18–38; 24 Female). DLco was measured using the single‐breath, breath‐hold technique and ATS/ERS standards. We compared DLco absolute, DLco% predicted and DLco/Alveolar volume (VA) absolute and DLco/VA %predicted. There were no significant differences between PFO+ and PFO− subjects as a group. There were no significant differences between PFO+ and PFOmen. However, PFO+ women had DLco and DLco/VA % predicted values that were 10% lower than PFO− women, though these values were still >100% predicted. Median and mean degree of resting PFO shunt scored with transthoracic saline contrast echocardiography were identical between men and women. In conclusion, these data suggest the degree of blood flow through the PFO under resting conditions may not explain the reason for the lower DLco observed in PFO+ women.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 01, 2018
- Source ID
- 10.1096/fasebj.2018.32.1_supplement.627.6
Entities
People
- A. Schallerer
- Andrew T Lovering
- James H Davis
- Travis Olson
Organizations
- American Thoracic Society
- Indiana State University
- United States Department of Defense
- University of Oregon