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Completed No phase listed Observational

Does Patent Foramen Ovale Size Matter in Men and Women

ClinicalTrials.gov ID: NCT03904277

Public ClinicalTrials.gov record NCT03904277. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 10, 2026, 3:25 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

A patent foramen ovale (PFO) is present in \~30% of the general population. The PFO has historically been considered to be trivial. However, recent work by the investigator's group and others has identified that, compared to individuals without a PFO, those with a PFO have worse pulmonary gas exchange efficiency, have a higher core body temperature, blunted ventilatory responses to chronic hypoxia and acute carbon dioxide and increased susceptibility to altitude illnesses such as acute mountain sickness, and high altitude pulmonary edema (Lovering, Elliott \& Davis J Appl Physiol 2016). Specific to this application,subjects with a PFO may have worse pulmonary gas exchange efficiency because a PFO is a potential source of right-to-left shunt that will make pulmonary gas exchange efficiency worse. If true, then this may negatively impact exercise capacity and/or exercise tolerance. Further, in those with a PFO compared to those without, preliminary work from the investigator's lab indicates that there may be an effect of PFO size on pulmonary gas exchange efficiency. This is such that those with a large PFO (grade 3 or higher) display significantly worse gas exchange efficiency compared to those with a small (grade 2 or lower) or no PFO,even at low exercise workloads. Additionally, the investigators were curious as to whether there would be a sex effect, but due to logistical constraints, the investigators were unable to recruit an equal number of female and male subjects. Thus, in addition to the potential size effect on the investigators outcome measures, the investigators would like to build on this work by examining the potential effect of biological sex. Although a PFO has been traditionally considered to have a minimal impact of physiology and pathophysiology, emerging evidence suggests this may not be the case. The investigator's lab is focused on understanding how and why a relatively small hole in the heart (PFO) can have a relatively large impact on cardiopulmonary and respiratory physiology, and how these impacts may be based on the size of the PFO.

Study identification

NCT ID
NCT03904277
Recruitment status
Completed
Study type
Observational
Phase
Not listed
Lead sponsor
University of Oregon
Other
Enrollment
28 participants

Conditions and interventions

Interventions

Not listed

Eligibility (public fields only)

Age range
18 Years to 40 Years
Sex
All
Healthy volunteers
Not listed

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Sep 30, 2018
Primary completion
Dec 30, 2022
Completion
Jan 24, 2023
Last update posted
Jan 31, 2023

2018 – 2023

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
Cardiorespiratory and Pulmonary Physiology Lab Eugene Oregon 97403

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT03904277, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Jan 31, 2023 · Synced Sep 10, 2026

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Open the official record

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