Does Patent Foramen Ovale Closure Improve Exercise Capacity & Prevent Blood Flow Through Intrapulmonary Shunt
Phase: NA
Conditions: Patent Foramen Ovale
Sponsor: University of Oregon

Does patent foramen ovale closure improve exercise capacity & prevent blood flow 
through intrapulmonary shunt? 
 
NCT ID: Not assigned 
 
Date: 12/11/18 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Study Title: Does patent foramen ovale closure improve exercise capacity & prevent 
blood flow through intrapulmonary shunt? 
Protocol Number: #12132016.027 
Principal Investigator: Andrew T Lovering, PhD  
 
A. Introduction and Background 
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 our group and others 
has identified that, compared to individuals without a PFO, those with a PFO have a higher 
core body temperature, significantly worse pulmonary gas exchange efficiency, 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 maybe 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. 
Our lab group has demonstrated that hypoxemia increases blood flow through 
intrapulmonary arteriovenous anastomoses (IPAVA) in healthy and subjects with COPD 
(Lovering, Duke & Elliott J Physiol, 2015; Norris et al Exp Physiol, 2016).  When these 
subjects breathe 100% O2 it prevents or reduces blood flow through IPAVA. This suggests 
that hypoxemia per se induces blood flow through IPAVA.  The blood flow through IPAVA 
and presence of a PFO is also associated with increased risk of stroke and/or transient 
ischemic attack (Duke, Elliott, Lovering Echocardiography 2015). In addition, an atrial septal 
defect (ASD) is a hole within the interatrial septum, and is considered a congenital heart 
defect. An ASD is typically larger than a PFO, and thus, the symptoms may be worse in those 
with an ASD, compared to those with a PFO. Thus, some hypoxemic patients who have had a 
stroke or transient ischemic attack, who also have a PFO/ASD may undergo surgical closure 
of their PFO/ASD to prevent subsequent neurological sequelae.  This surgical closure may 
also prevent the hypoxemia thereby reducing or preventing blood flow through IPAVA. Of 
note, blood flow through IPAVA has been demonstrated to be strongly correlated with TIA 
and/or stroke and has not previously been taken into consideration in randomized clinical 
trials mentioned below (Abushora et al JASE, 2013). 
Three randomized clinical trials have determined that PFO closure is not superior to regular 
medical management, for the prevention of subsequent stroke and/or TIA. Nevertheless, 
the American Heart Association still recommends that “in patients with cryptogenic 
[unexplained] TIA or stroke, a PFO, and DVT, guidelines from the American College of Chest 
Physicians currently recommend vitamin K antagonist therapy for 3 months and 
consideration of PFO closure rather than no vitamin K antagonist therapy or aspirin 
therapy.” (Whitlock et al., CHEST 2012; 141(2)(Suppl):e576S–e600S, Kernan et al., Stroke. 
2014;45:2160-2236). Additionally, in the largest single center retrospective study performed 
to date, PFO closure for the purpose of preventing hypoxemia was found to result in 
“improvement in echocardiographic evidence of right to left shunt, New York Heat 
Association functional class, and oxygen requirement.” (Fenster et al Am J Cardiol 2013). 

Thus, PFO/ASD closure remains a potentially beneficial option for both hypoxemic and 
stroke/TIA patients. 
 
Lastly, preliminary data also suggest greater levels of plasma inflammatory mediators in 
subjects with a PFO and systemic inflammation is associated with increased risk of 
cardiovascular diseases.  Importantly, exercise is known to reduce so of these systemic 
inflammatory mediator levels. Thus, PFO/ASD closure may allow for greater exercise 
capacity and a subsequent reduction in inflammation. 
Thus, 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.  Our 
lab is focused on understanding how and why a relatively small hole in the heart (PFO/ASD) 
can have a relatively large impact on cardiopulmonary and respiratory physiology. 
B. Specific Aims/Study Objectives 
The overarching goal of this study is to examine cardiopulmonary and respiratory 
physiology pre and post PFO/ASD closure in patients who are undergoing surgical 
closure of their PFO/ASD. 
Pre and post PFO/ASD closure, we will: 
1) Quantify pulmonary gas exchange efficiency (alveolar to arterial O2 difference) and 
arterial oxygenation at rest and during exercise. 
2) Quantify aerobic exercise capacity, daily activity, six-minute walk test. 
3) Quantify QIPAVA at rest and assess recurrence of stroke or TIA at 3 months. 
4) Quantify plasma inflammatory markers (TNFa, IL-1, 6 & CRP)  
5) Measure hypercapnic ventilatory response 
6) Quantify core body temperature 
Hypotheses: We hypothesize that closure of PFO/ASD will improve pulmonary gas 
exchange efficiency, improve exercise capacity, and reduce blood flow through 
PFO/ASD and IPAVA thereby preventing subsequent stroke.  PFO/ASD closure will 
also reduce plasma inflammatory mediators, increase ventilation in response to a 
hypercapnic challenge, and will result in a lower core body temperature. 
C. Methods, Materials and Analysis 
This study will be performed over the course of 7 days at the Cardiopulmonary and 
Respiratory Physiology Lab at the University of Oregon. Days 1-3 are Pre-PFO/ASD closure 
procedure and Days 4-7 repeat all research activities beginning at 3 months post PFO/ASD 
closure procedure. Those cleared for exercise by their cardiologists (see recruitment below) 

will participate in all aspects of the study, Days 1-7.  Those not cleared for exercise by their 
cardiologists will participate in all non-exercise aspects of the study Days 1-4 [gray highlight 
for non-exercise subject information]. 
Special note on post PFO/ASD closure procedures: The timing of post PFO/ASD closure 
procedure visits were carefully selected (i.e., 3 and 6 months) based on recommendations 
from the referring physicians (Dr. Richard Padgett and Dr. Samuel Lau). It is their collective 
recommendation that 6 months (and in some cases 3 months) is sufficient to allow for 
physical closure/endothelialization of the PFO/ASD. However, if is it determined at 6 months 
post PFO/ASD closure procedure that the PFO/ASD has been deemed NOT PHYSICALLY 
CLOSED/ENDOTHELIALIZED by the referring physician, the subject will not partake in the 
post-closure visit(s) scheduled at 6 months, AND they will be excluded from the study. 
Screening at each study visit: Female subjects will be required to take a urine pregnancy 
test before each visit begins. A positive test at anytime will result in exclusion. A Modified 
Allen’s test will be performed on Day 1 for all subjects and during each day when an arterial 
line is placed.  Failing the Modified Allen’s test at anytime will result in exclusion. 
Protected Health Information (PHI):  Participating Physicians Dr. Padgett and Lau will 
provide PHI to the investigators. The PHI provided will include: the reason(s) for PFO/ASD 
closure procedure (e.g., TIA, Stroke, dyspnea upon exertion, etc.), when the PFO/ASD has 
physically closed/endothelialized per referring physician (e.g., at 3 or 6 months), current and 
past medication information, and results from clinical exercise studies as they pertain to 
determining the reason(s) for closure (e.g., arterial oxygen saturation at rest and during 
exercise, rating of perceived exertion, etc). Subjects will be asked to sign a HIPAA 
authorization form on Day 1. The PHI will be used for research purposes only.  Of note, this 
information is only solicited via self-report from those who have reported a prior history at 
the time of enrollment. 
The following Figures (i.e., 1 & 2) are meant to assist in determining the path through the 
study days, and should be used in conjunction with the detailed study-day descriptions. 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
This portion left intentionally blank 
 
 
Figure 1. Exercise 

 
 
 
PFO Closure Procedure
3 months
PFO Physically Closed/Endothelialized per Physician?
YES
NO
Visits 4 - 6a
Visit 7a OR 5 - 7b
Visit 4b
6 months
Timing
PFO Physically Closed/Endothelialized per Physician?
YES
NO
You will be excluded from the study
Consent to Participate in Study
Visits 1 - 3
Pre-Procedure
PFO/AS
PFO/AS
PFO/AS

 
Figure 2. Non-Exercise  
 
PFO Closure Procedure
3 months
PFO Physically Closed/Endothelialized per Physician?
YES
NO
Visit 3a
Visit 4a OR 4b
Visit 3b
6 months
Timing
PFO Physically Closed/Endothelialized per Physician?
YES
NO
You will be excluded from the stu
Consent to Participate in Study
Visits 1 & 2
Pre-Procedure
PFO/AS
PFO/AS
PFO/AS

 
 
 
EXERCISE SUBJECTS 
What follows is a detailed description of the study days. For convenience, please refer to 
Figure 1. Exercise (page 4) to assist in determining the timing of study days. 
Visit 1 Pre PFO/ASD Closure Procedure (~2.5hrs) AND:  
Visit 4a (PFO/ASD Physically Closed/Endothelialized) (~2 hours) OR, 
Visit 4b (PFO/ASD Not Physically Closed/Endothelialized) (~30 min) 
Visit 4a (If PFO/ASD is physically closed/endothelialized at 3 months per referring 
physician) 
Subjects will undergo informed consent, fill out health history questionnaire, sign a HIPAA 
authorization form and perform a Modified Allen’s Test (~45 min) 
Subjects will be comprehensively screened for any cardiac abnormalities. Amount of blood 
flow travelling through the PFO/ASD and IPAVA will be graded using saline contrast 
echocardiography while the subject is breathing room air (PFO/ASD and IPAVA blood flow) 
and breathing 100% O2 (PFO/ASD blood flow only). Pulmonary artery pressure will also be 
measured using ultrasound. Intravenous blood draw, we will take 21mls (~2 Tablespoons) of 
iv blood (~1.25 hrs) 
Subjects will perform pulmonary function, plethysmography and diffusing capacity (30min) 
Visit 4b (If PFO/ASD is not physically closed/endothelialized at 3 months per referring 
physician) 
Subjects will receive and intravenous blood draw, and we will take 21mls (~2 Tablespoons) 
of IV blood (30 min). 
Visit 2 Pre PFO/ASD Closure Procedure (~2.5 hrs) AND:  
Visit 5a (PFO/ASD Physically Closed/Endothelialized) (~2.5 hrs) OR, 
Visit 5b (PFO/ASD Not Physically Closed/Endothelialized) (~2 hrs): 
Visit 5a (If PFO/ASD physically closed/endothelialized) at 3 months per referring physician) 
Subjects will undergo a hypercapnic breathing challenge (~1hr) 
Subjects will be given an activity monitor and given instructions on how and when to use it 
(~30 min) (Detailed Instructions on Visit 2 ONLY. On Visit 5, they will be reminded of the 
instructions, with details as required) 
Subjects will perform a 6 minute walk test (~15 min) 

Subjects will perform a VO2max test (~30 min) 
Visit 5b (If PFO/ASD not physically closed/endothelialized at 3 months per referring 
physician) 
Subjects will undergo informed consent, fill out health history questionnaire, sign a HIPAA 
authorization form and perform a Modified Allen’s Test (~45 min) 
Subjects will be comprehensively screened for any cardiac abnormalities. Amount of blood 
flow travelling through the PFO/ASD and IPAVA will be graded using saline contrast 
echocardiography while the subject is breathing room air (PFO/ASD and IPAVA blood flow) 
and breathing 100% O2 (PFO/ASD blood flow only). Pulmonary artery pressure will also be 
measured using ultrasound. Intravenous blood draw, we will take 21mls (~2 Tablespoons) of 
iv blood (~1.25 hrs) 
Subjects will perform pulmonary function, plethysmography and diffusing capacity (30min) 
Visit 3 Pre PFO/ASD Closure Procedure (~5 hrs) AND: 
Visit 6a (PFO/ASD Physically Closed/Endothelialized) (~5 hrs) OR, 
Visit 6b (PFO/ASD Not Physically Closed/Endothelialized) (~2.5 hrs) 
Visit 6a (If PFO/ASD physically closed/endothelialized at 3 months per referring physician) 
Subjects will be instrumented with a radial artery catheter by Dr. Jerry Hawn, MD. An 
esophageal temperature probe and an iv for saline contrast injections will also be placed. 
(~1hr) 
Arterial blood will be taken at rest while subject is breathing room air and 100% O2 for 10-
20 minutes to calculate shunt fraction (~30 min). 
Subjects will exercise on a cycle ergometer for 4 minutes per stage at 25, 50, 75 and 90% of 
VO2 max breathing room air. Subjects will take up to 15 minute breaks between exercise 
stages (~1.5hr) 
After exercise breathing room air, subjects will take a 30-minute break. (~30min) 
Subject will repeat the exercise protocol above while breathing 40% O2 (~1.5hrs); note 60% 
O2   is the maximal level of oxygen that can be breathed and still get metabolic data 
required for calculating the AaDO2. 
Visit 6b (If PFO/ASD not physically closed/endothelialized at 3 months per referring 
physician) 
Subjects will undergo a hypercapnic breathing challenge (~1hr) 
Subjects will be given an activity monitor and given instructions on how and when to use it 
(~30 min) (Detailed Instructions on Visit 2 ONLY. On Visit 6b, they will be reminded of the 
instructions, with details as required) 
Subjects will perform a 6 minute walk test (~15 min) 

Subjects will perform a VO2max test (~30 min) 
Visit 7a (PFO/ASD Physically Closed/Endothelialized) (~ 30 mins) OR, 
Visit 7b (PFO/ASD Not Physically Closed/Endothelialized) (~ 5 hrs) 
Visit 7a (If PFO/ASD physically closed/endothelialized at 3 months per referring physician) 
Intravenous blood draw. We will take roughly 21 mls (~2 Tablespoons) of IV blood. 
Visit 7b (If PFO/ASD not physically closed/endothelialized at 3 months per referring 
physician) 
Subjects will be instrumented with a radial artery catheter by Dr. Jerry Hawn, MD. An 
esophageal temperature probe and an iv for saline contrast injections will also be placed. 
(~1hr) 
Arterial blood will be taken at rest while subject is breathing room air and 100% O2 for 10-
20 minutes to calculate shunt fraction (~30 min). 
Subjects will exercise on a cycle ergometer for 4 minutes per stage at 25, 50, 75 and 90% of 
VO2 max breathing room air. Subjects will take up to 15 minute breaks between exercise 
stages (~1.5hr) 
After exercise breathing room air, subjects will take a 30-minute break. (~30min) 
Subject will repeat the exercise protocol above while breathing 40% O2 (~1.5hrs); note 60% 
O2   is the maximal level of oxygen that can be breathed and still get metabolic data 
required for calculating the AaDO2. 
NON-EXERCISE 
What follows is a detailed description of the study days. For your convenience, please refer 
to Figure 2. Non- Exercise (page 5) to assist in determining the timing of study days. 
Visit 1 Pre PFO/ASD Closure Procedure (~2.5hrs):  
Subjects will undergo informed consent, fill out health history questionnaire and perform a 
Modified Allen’s Test (~45 min) 
Subjects will be comprehensively screened for any cardiac abnormalities. Amount of blood 
flow travelling through the PFO/ASD and IPAVA will be graded using saline contrast 
echocardiography while the subject is breathing room air (PFO/ASD and IPAVA blood flow) 
and breathing 100% O2 (PFO/ASD blood flow only). Pulmonary artery pressure will also be 
measured using ultrasound. Intravenous blood draw, we will take 21mls (~2 Tablespoons) of 
iv blood (~1.25 hrs) 
Subjects will perform pulmonary function, plethysmography and diffusing capacity (30min) 
Visit 2 Pre PFO/ASD Closure Procedure (~3 hrs):  
Subjects will undergo a hypercapnic breathing challenge (~1hr) 

Subjects will be given an activity monitor and given instructions on how to use it (~30 min)( 
Detailed Instructions on Visit 2 ONLY. On Visit 3, they will be reminded of the instructions, 
with details as required) 
Subjects will be instrumented with a radial artery catheter by Dr. Jerry Hawn, MD. An 
esophageal temperature probe and an iv for saline contrast injections will also be placed. 
(~1hr).   
Arterial blood will be taken at rest while subject is breathing room air and 100% O2 for 10-
20 minutes (~30 min).  
Visit 3a (PFO/ASD Physically Closed/Endothelialized) (~4.5 hrs) OR, 
Visit 3b (PFO/ASD Not Physically Closed/Endothelialized) (~30 min) 
Visit 3a (If PFO/ASD physically closed/endothelialized at 3 months per referring physician) 
Subjects will be instrumented with a radial artery catheter by Dr. Jerry Hawn, MD. An 
esophageal temperature probe and an iv for saline contrast injections will also be placed. 
(~1hr).  
Arterial blood will be taken at rest while subject is breathing room air and 100% O2 for 10-
20 minutes to calculate shunt fraction (~30 min). 
Subjects will be comprehensively screened for any cardiac abnormalities. Amount of blood 
flow travelling through the PFO/ASD and IPAVA will be graded using saline contrast 
echocardiography while the subject is breathing room air (PFO/ASD and IPAVA blood flow) 
and breathing 100% O2 (PFO/ASD blood flow only). Pulmonary artery pressure will also be 
measured using ultrasound. Intravenous blood draw, we will take 21mls (~2 Tablespoons) of 
iv blood (~1.25 hrs) 
Subjects will perform pulmonary function, plethysmography and diffusing capacity (30min) 
Subjects will undergo a hypercapnic breathing challenge (~1hr)  
Visit 3b (If PFO/ASD not physically closed/endothelialized at 3 months per referring 
physician) 
Subjects will undergo an intravenous blood draw, and we will take 21mls (~2 Tablespoons) 
of IV blood (30 min). 
Visit 4a (PFO/ASD Physically Closed/Endothelialized) (~30 min) OR,  
Visit 4b (PFO/ASD Not Physically Closed/Endothelialized) (~4.5 hrs) 
Visit 4a (If PFO/ASD physically closed/endothelialized at 3 months per referring physician) 
Subjects will undergo an intravenous blood draw, and we will take 21mls (~2 Tablespoons) 
of IV blood (30 min). 
Visit 4b (If PFO/ASD not physically closed/endothelialized at 3 months per referring 
physician) 

Subjects will be instrumented with a radial artery catheter by Dr. Jerry Hawn, MD. An 
esophageal temperature probe and an iv for saline contrast injections will also be placed. 
(~1hr).   
Arterial blood will be taken at rest while subject is breathing room air and 100% O2 for 10-
20 minutes to calculate shunt fraction (~30 min). 
Subjects will be comprehensively screened for any cardiac abnormalities. Amount of blood 
flow travelling through the PFO/ASD and IPAVA will be graded using saline contrast 
echocardiography while the subject is breathing room air (PFO/ASD and IPAVA blood flow) 
and breathing 100% O2 (PFO/ASD blood flow only). Pulmonary artery pressure will also be 
measured using ultrasound. Intravenous blood draw, we will take 21mls (~2 Tablespoons) of 
iv blood (~1.25 hrs) 
Subjects will perform pulmonary function, plethysmography and diffusing capacity (30min) 
Subjects will undergo a hypercapnic breathing challenge (~1hr)  
Description of Data Collection Procedures (timing of these procedures can be found in 
Table 1 and 2 below:  
• 
Modified Allen’s Test (Days 1, 3 & 6a OR 7b Exercise; Days 1, 2 & 3a OR 4b NON-
Exercise): 
This test examines collateral blood flow in the hand, and is performed on the first day and 
each day there is an arterial line placed. The subject clenches their fist for ~30 seconds while 
the radial and ulnar arteries are occluded by the investigator.  The ulnar artery is released 
and the return of circulation (color to the hand) is examined.  If the color doesn't return, 
then this is considered a negative test (fail).  Both hands will be tested, two failures (right 
and left hand) is exclusionary. 
• 
Comprehensive ultrasound screening (Days 1 & 4a OR 5b Exercise; Days 1 & 3a OR 4b 
NON-Exercise):  
An intravenous catheter will be placed in the subject.  Subjects will sit in the left lateral 
decubitis position for ultrasound screening.  An agitated saline contrast injection will be 
made while transthoracic saline contrast echocardiography (TTSCE) is performed on the 
subject to evaluate extent of blood flow through IPAVA and PFO/ASD.  This will be repeated 
while breathing 100% O2 for 10 minutes.  Subject will be asked to perform a Valsalva 
maneuver while breathing room air and 100% O2. This maneuver enhances blood flow 
across the PFO/ASD. Multiple saline contrast injections (up to 3) may be performed to verify 
bubble grades/presence of a PFO/ASD. 
Pulmonary Function Tests (Days 1 & 4a OR 5b Exercise; Days 1 & 3a OR 4b NON-Exercise):  
• 
Subjects will perform standard non-invasive spirometry to measure a maximal 
inspiratory and expiratory flow-volume loop, forced vital capacity (FVC), forced expiratory 
volume in 1 sec (FEV1), and mid expiratory flow (FEF25-75%). These tests will require the 
subject to blow in and out of a mouthpiece connected to a computerized flowmeter 
(pneumotachometer). This is a routine clinical test performed in pulmonary function labs in 
the United States. 

• 
Diffusing Capacity (DLCO) (Days 1 & 4a OR 5b Exercise; Days 1 & 3a OR 4b NON-
Exercise):  
This is a standard non-invasive test for diffusion capacity for carbon monoxide (CO) using 
the single breath, breath-hold technique. It requires the subject to breathe in a single breath 
of a commercially available (MedGraphics/Airgas) diffusion gas containing 0.3% CO. The 
subject will breathe in this breath through a mouthpiece connected to a flowmeter and hold 
it for approximately 10 seconds before exhaling the gas. This may be repeated a maximum 
of 3 to 5 times. This is a routine clinical test performed in pulmonary function labs in the 
United States. 
• 
Whole Body Plethysmography (Days 1 & 4a OR 5b Exercise; Days 1 & 3a OR 4b NON-
Exercise):  
Subjects perform a standard non-invasive procedure to measure functional residual capacity 
(FRC), which is the amount of air within the lungs at the end of a passive expiration. Subjects 
also perform a standard non-invasive slow vital capacity (SVC) maneuver to determine the 
vital capacity (usable capacity) of the lungs. These procedures will require the subject to sit 
inside a clear plexiglass box called a whole body plethysmograph (MedGraphics Elite) and 
breathe room air through a mouthpiece (pneumotachometer) connected to a flowmeter. 
Using the value obtained for FRC and the value obtained for SVC total lung capacity (TLC) 
can be determined. This is a routine clinical test performed in pulmonary function labs in the 
United States. 
• 
Nitrogen Washout (Days 1 & 4a OR 5b Exercise; Days 1 & 3a OR 4b NON-Exercise):   
Subjects may perform a standard non-invasive procedure to measure residual volume for 
calculation of total lung capacity. This procedure will require subjects to breathe 100% 
oxygen through a mouthpiece for 7-10 minutes while we monitor nitrogen washout of the 
lungs. This will be done following ATS/ERS standard criteria. This is a routine clinical test 
performed in pulmonary function labs in the United States. This will only be performed if the 
plethysmograph is not functioning properly, i.e. it is a contingent test. Of note we have 
never needed to perform this test. 
• 
Transthoracic Saline Contrast Echocardiography (TTSCE) (Days 1, 3, 4a OR 5b & 6a OR 7b 
Exercise; Days 1-3a OR 4b NON-Exercise): 
Echocardiography requires a medical sonographer from PeaceHealth to place a small probe 
against the subject's ribcage, which transmits and receives sound waves to produce images 
that are captured and stored on a computer. Saline contrast is made by manually agitating 
(mixing) 3-5 ml of sterile saline and 1 ml of air to create a suspension (mixture of liquid and 
gas) of very small bubbles called microbubbles. This suspension is injected through an IV, 
which allows us to detect the transpulmonary passage of microbubbles.  
• 
Intravenous Catheter (IV) (Days 1,3,4a OR 4b, 5b, 6a, 7a OR 7b Exercise; Days 1-3a, 4a 
OR 4b NON-Exercise):  
We will place a 20-22 gauge (small diameter) IV into a vein in the subject’s arm that will be 
used for the rapid injection of the agitated sterile saline for TTSCE during Days 1,3,4a OR 4b, 
5b, 6a, and 7a OR 7b Exercise; Days 1-4 NON-Exercise. This catheter will also be used to 
measure plasma inflammatory mediators. Blood will be centrifuged and de-identified 
plasma stored at -80°C until assayed by ELISA kit. Total IV blood draw is approximately 63 
mL for exercise or non-exercise participants. 

• 
Hypercapnic ventilatory response (Days 2 & 4a OR 5b Exercise; Days 2-3a OR 4b NON-
Exercise):  
We will use a published, well-established method (Duffin method) for assessing chemo 
sensitivity to carbon dioxide (MacKay et al., Adv Physiol Education, 2016). Subjects will be 
fitted with a nose-clip and breathe room air through a two-way rebreathing valve that can 
be directed between a filtered 6L non-diffusing bag filled with 7% CO2 and 93% O2 (medical 
grade) and room air. Ventilation, end tidal CO2 (PETCO2), end tidal O2 (PETO2) and 
saturation will be measured continuously throughout this testing (Medgraphics).  To 
establish a baseline before hypercapnic testing using the modified rebreathing protocol, 
subjects will breathe room air for 5 min. Subjects will then be coached to hyperventilate by 
increasing the lung volume and frequency of breathing for 5 minutes to reach a target 
PETCO2 of ~20-25 mm Hg (~40-45 mm Hg is normal); this part of the test is required to 
reduce CO2 stores in the body. At 5 minutes the subject will be asked to take a full breath in 
and out then they will be switched to the bag filled with 7% CO2 and 93% O2 and will be 
coached to take 3 large breaths then resume normal breathing until: 1) their breathing 
increases so much that it becomes in tolerable and they signal to quit; 2) the PETCO2 = 55 
mm Hg or 3) the rebreathing bag becomes deflated. Subjects will be informed of what to 
expect with this test prior to performing it, i.e they will be told that we will coach them 
through it and that when they start to breathe out of the bag they will initially have very 
little urge to breathe but as the rebreathing progresses they will have a very strong urge to 
breathe. 
• 
Actigraphy (Days 2 & 4a OR 5b Exercise; Days 2-3a OR 4b NON-Exercise):  
All subjects will wear an ActiGraph (Pensacola, FL) GT3X accelerometer daily for 
approximately 1 week  Pre PFO/ASD closure (baseline) and 1 week Post PFO/ASD closure. 
Subjects will be instructed to wear the device at all times around their waist except when 
showering, bathing, swimming, or sleeping. Accelerometry data will be downloaded to a 
computer using ActiLife v.6 software. Total daily energy expenditure (TDEE; kcal/day) will be 
estimated, and physical activity levels (PALs; TDEE/basal metabolic rate [BMR]) calculated to 
adjust for body size. Activity energy expenditure (AEE; kcal/day), calculated as TDEE-BMR, 
will be used to describe the caloric costs of physical activity. In addition, time spent in 
standard categories of activity (sedentary, moderate, vigorous) will be assessed. Members 
of the Lovering lab are responsible for uploading and analyzing de-identified data from the 
ActiGraphs every week. 
 
• 
VO2MAX test and 6 minute walk test (Days 2 & 4a OR 5b; Exercise subjects Only):  
The six minute walk test will be performed on the second floor of the Center for Medical 
Education and Research. This is the same space used to perform these tests in Dr. Dreyer’s 
subjects. 
The VO2max test will be an incremental test to volitional exhaustion on a cycle ergometer. 
Subjects will breathe through a mouthpiece and will begin cycling at a very low resistance 
(25 to 75 W depending on fitness level), with the resistance increasing every minute by 25 
W. The test will continue until the subject reaches volitional exhaustion or a plateau in VO2 
as measured by our metabolic cart is reached. During the entire protocol, subjects will 
breathe room air through a 2-way non-rebreathing small sampling flowmeter 

(pneumotachometer), which will allow us to measure ventilation (VE), VO2, and breath-by-
breath metabolic data. Subjects will be instrumented with 12 lead EKG. 
• 
Arterial Blood Gas Measurement (Days 3, 6a OR 7b Exercise subjects; Days 2-3a OR 4b 
NON-Exercise subjects):  
Prior to catheter placement the physician will perform a modified Allen’s Test to confirm 
adequacy of collateral circulation of the hand. A physician (Jerold Hawn, MD) will perform 
catheterization of the radial artery.  Using a standard, sterile procedure Dr. Hawn will place 
a small catheter into the radial artery (arterial catheterization).   Dr. Hawn will initially numb 
the wrist with lidocaine/nitroglycerin solution. Then Dr. Hawn will place a needle into the 
radial artery.  Dr. Hawn will then place a small guide wire through the needle in to the 
vessel.  Then he will place a flexible catheter into the vessel using the guide wire for 
direction. This catheter will be used to collect blood totaling <100 mL (< 7 Tablespoons) in 
the exercising subjects and  < 25 ml (<2 Tablespoons) in resting subjects.  Blood draws will 
be accompanied by a heparinized saline flush (1unit heparin/ml) to reduce chances of 
catheter clotting. 12 lead ECG, heart rate, metabolic, ventilation data will be continuously 
collected and arterial blood oxygen saturation will be continuously measured via a non-
invasive transcutaneous forehead sensor.  
*Note:  
TOTAL blood draw for Exercise subjects (i.e., IV + Arterial Line) will be less than 250 mL. 
TOTAL blood draw for Non-Exercise subjects (i.e., IV + Arterial Line) will be less than 125 mL. 
However, if it is deemed at 6 months by the referring physician that the PFO/ASD has not 
been physically closed/endothelialized, subjects will not partake in the scheduled 6-month 
post PFO/ASD closure procedure visits. Thus, the amount of blood drawn from these 
subjects would be significantly reduced. Specifically: 
Exercise subjects without 6 month visits (i.e., total blood drawn): < 125 mL 
Non-exercise subjects without 6 month visits (i.e., total blood drawn): < 75 mL 
Risks and interventions to mitigate such are included in Section G. 
• 
Exercise with arterial line (Days 3, 6a OR 7b Exercise subjects only):  
After arterial line placement (see above) the subjects will perform two bouts of graded 
submaximal exercise tests on the cycle ergometer at 25%, 50%, 75% and 90% of their VO2max 
with each stage lasting 4 minutes with up to 15 minute breaks between stages.  During one 
bout, subjects will breathe normal oxygen levels (21% oxygen), during the other bout, 
subjects will breathe high oxygen levels (40% oxygen).  Bouts will be randomized and 
separated by 30 minutes of rest breathing room air.  
• 
Intrapulmonary & intracardiac Shunting with arterial line placement (Days 3, 6a OR 7b 
Exercise subjects; Days 2-3a OR 4b NON-Exercise subjects):  
Saline contrast echocardiography will be performed during the third minute of each exercise 
stage to assess intrapulmonary and intracardiac shunting. Saline contrast echocardiography 
will also be performed in NON-exercise subjects at rest. 

• 
Measurement of core body temperature (Days 3, 6a OR 7b Exercise subjects; Days 2-3a 
OR 4b NON-Exercise subjects):  
An esophageal temperature probe (Nelcor used with Mon-a-Therm System) will be 
placed. We will be using esophageal temperature monitoring because core temperature 
is a primary outcome variable of this study and esophageal temperature is considered to 
be the gold standard technique for measuring core temperature during short duration 
exercise testing.  We also use this temperature to correct our blood gas values.  In order 
to place the esophageal probe, subjects will be given lidocaine Jelly (2% lidocaine, 1 ml 
intranasal administration). After administration of the lidocaine Jelly, researchers will 
place the esophageal probe through one of the nostrils, and advance the probe until it is 
visible in the back of the throat. Once the probe is visible, the subject will then begin to 
sip water through a straw while the researcher advances the probe to the appropriate 
depth. The swallowing of the water helps to insure that the probe goes down the 
esophagus and not the trachea. Researchers will make no more than 2 attempts per 
nostril to place the esophageal probe. In the event subjects cannot tolerate the 
esophageal temperature probe, subjects will swallow an ingestible pill, about the size of 
a multi-vitamin, that is designed for human use (FDA approved) and is accurate to 0.1ºC 
(CoreTemp, HQI Technologies, Inc.).  This pill will be used to measure core body 
temperature at rest and during cycle ergometer exercise. Prior to ingestion the 
temperature pill will be calibrated with an external wireless recording device. This will 
allow us to wirelessly acquire the subjects core temperature when necessary as the 
temperature pill transmits a signal to the external device that will then display the 
appropriate temperature. This pill will harmlessly pass through the subject’s intestinal 
tract. The pill is not recovered, is disposable, and every subject receives a new pill for 
each study day.  
Table 1 – Exercise  
Group - Exercise 
 
 
 
 
 
Visits: 
1 
2 
3 
4
a 
4
b 
5
a 
5
b 
6a 
6
b 
7
a 
7b 
Pre- PFO/ASD Close 
x 
x 
x 
 
 
 
 
 
Post-PFO/ASD Close 
x 
x 
x 
x 
x 
x 
x 
x 
Study Procedures: 
  
  
  
  
 
  
 
  
 
 
 
IC & Health Hx, HIPAA form 
x 
 
 
 
 
 
Modified Allen Test 
x 
x 
 
 
x 
 
 
x 
Comprehensive Screening 
x 
x 
 
x 
 
 
 
Pulmonary Function 
x 
x 
 
x 
 
 
 
Diffusing Capacity 
x 
x 
 
x 
 
 
 
Plethysmography 
x 
x 
 
x 
 
 
 
Nitrogen Washout* 
x 
x 
 
x 
 
 
 
Transthoracic Saline Contrast Echo 
(TTSCE) 
x 
 
x 
x 
 
 
x 
x 
 
 
x 
Intravenous catheter (IV) 
x 
x 
x 
x 
x 
x 
 
x 
x 
Hypercapnic Ventilatory Response 
x 
 
x 
x 
 
 
 

Actigraphy** 
x 
x 
 
x 
 
 
 
VO2Max & 6 min walk 
x 
x 
 
x 
 
 
 
Arterial Blood Gas Measurement 
x 
 
 
x 
 
 
x 
Exercise w/arterial line 
x 
 
 
x 
 
 
x 
Intrapulmonary/intracardiac shunt 
w/art line 
 
 
x 
 
 
 
 
x 
 
 
x 
Core Body Temp 
x 
 
 
x 
 
 
x 
Compensation: 
  
  
  
  
 
  
 
  
 
 
 
IC & Health Hx 
5 
 
 
 
 
 
Echo screen/blood draw 
1
0 
 
 
1
5 
 
 
1
5 
 
 
 
 
Blood Draw 
 
 
 
 
1
0 
 
 
 
 
1
0 
 
PFT, diff capacity, plethysmography 
1
0 
 
 
1
5 
 
 
1
5 
 
 
 
 
Hypercapnic breathing challenge 
 
1
0 
 
 
 
1
5 
 
 
1
5 
 
 
activity monitor training 
5 
 
 
 
 
 
six min walk 
5 
 
5 
 
5 
 
 
vo2max 
 
1
5 
 
 
 
1
5 
 
 
1
5 
 
 
arterial line 
 
 
10
0 
 
 
 
 
13
0 
 
 
13
0 
exercise tests 
 
 
75 
 
 
 
 
10
0 
 
 
10
0 
blood draws/breathing room air 
 
 
 
 
 
 
 
 
 
 
 
Total for completed study visit 
2
5 
3
5 
17
5 
3
0 
1
0 
3
5 
3
0 
23
0 
3
5 
1
0 
23
0 
Total for all aspects of the study 
 
 
540 
 
 
 
Table 2 – Non-Exercise 
Group – Non-Exercise 
Visits: 
     1        2       3a     3b     4a      4b 
Pre- PFO/ASD Close 
x 
x 
Post-PFO/ASD Close 
x 
     x 
     x 
      x 
Study Procedures: 
 
 
 
IC & Health Hx, HIPAA form 
x 
Modified Allen Test 
x 
x 
x 
x 
Comprehensive Screening 
x 
x 
x 
Pulmonary Function 
x 
x 
x 
Diffusing Capacity 
x 
x 
x 

Plethysmography 
x 
x 
x 
Nitrogen Washout* 
x 
x 
x 
Transthoracic Saline Contrast Echo (TTSCE) 
x 
x 
x 
x 
Intravenous catheter (IV) 
x 
x 
x 
x 
x 
Hypercapnic Ventilatory Response 
x 
x 
x 
Actigraphy** 
x 
x 
x 
VO2Max & 6 min walk 
Arterial Blood Gas Measurement 
x 
x 
x 
Exercise w/arterial line 
Intrapulmonary/intracardiac shunt w/art line 
x 
x 
x 
Core Body Temp 
x 
x 
x 
Compensation: 
IC & Health Hx 
5 
Echo screen/blood draw 
1
 
 
 
 
 
Blood draw 
 
 
 
10 
10 
 
PFT, diff capacity, plethysmography 
1
 
 
 
 
 
Hypercapnic breathing challenge 
10 
15 
15 
activity monitor training 
5 
six min walk 
vo2max 
arterial line 
100 
130 
130 
exercise tests 
blood draws/breathing room air 
15 
20 
20 
Total for completed study visit 
25 
130 
165 
10 
10 
165 
Total for all aspects of the study 
330 
 
D. Research Population & Recruitment Methods & Compensation 
1-2. Sample size, Population and Recruitment Methods: 
Sample Size and Data Analyses: 
Necessary sample size was determined with our primary outcome variables (AaDO2, VO2MAX, 
saline contrast bubble scores, TNFa levels) using our preliminary data, previously published 
work and a priori power analysis. Using G-Power and information about a physiologically-
meaningful effect from published studies (i.e. reduction of AaDO2 by 50%, VO2MAX increasing 
by 10% and 6 min walk test increasing by 50 meters (15, 34, 41){(24, 40)(24, 40){, TNF-a levels 
decreasing by 50%, a desired power of 0.80, and alpha (0.05), we determined that n = 8-10 
individuals would be sufficient to test our hypotheses, using a repeated measures design. 
Thus, we are asking to recruit 20 subjects (any combination of male and female) in the event 

our actual pre-to-post changes are less than expected and/or there is greater variability than 
our preliminary data suggest.  
Mean differences in AaDO2 and core body temperature between pre- and post-PFO/ASD 
closure will be analyzed using a repeated measures ANOVA with Tukey posttest. Mean 
differences in VO2MAX, 6 minute walk test, activity, inflammatory markers and hypercapnic 
ventilator response, between pre and post PFO/ASD closure will be analyzed using a paired 
t-test. Differences in bubble scores pre- and post-closure will be analyzed using a Mann-
Whitney U test.  
The population of subjects will include patients who are undergoing PFO/ASD closure at 
either PeaceHealth or McKenzie-Willamette Hospitals.  Subjects will be identified by Rick 
Padgett, MD (PeaceHealth/Oregon Heart & Vascular Institute) and Sam Lau, MD (McKenzie-
Willamette). These two cardiologists will only refer subjects to contact the Lovering Lab for 
informed consent and enrollment into the study.  Drs. Lau and Padgett will identify potential 
subjects as “cleared for exercise” or “not cleared for exercise.” (See statement of PHI 
above). Drs. Lau and Padgett will not be formally engaged in the research (i.e. they will not 
consent subjects, have access to identifiable data, etc). No research activities will take place 
at either hospital. Subject fliers, initial phone script and email script are attached. 
 
3. Detailed Recruitment information: 
A) Patients undergoing PFO/ASD closure will be identified by Dr. Lau and Padgett. The PI has 
verbally discussed the details of this study over the phone with Drs. Lau and Padgett.  The 
reality is that the three of us have been discussing the potential to do these studies for years 
and we only recently received the funding to do them.  The PI will send the cardiologist the 
criteria listed below in Table 3 so that they can refer to them before making the decision to 
recommend them for the study.  Because Drs. Lau and Padgett understand that this study 
has an exercise arm and a non-exercise arm, they will use their best judgment along with 
available medical records to determine whether or not a subject would be cleared for 
exercise or not cleared for exercise. For example, a subject with a history of chest pain upon 
exertion and a clinical exercise study revealing an elevated ST segment (EKG abnormality) 
would not qualify for the exercise study whereas a subjects with history of running 
marathons would qualify for the exercise study. 
B) If the cardiologist believes that their patient meets the qualifications for this study, they 
will simply hand them a flier (either the exercise or non-exercise flier based on cardiologist 
recommendation) and direct them to contact us (Lovering and colleagues) for questions. 
C) Once a subject contacts us and agrees to come in for consent (after receiving a flier from 
their physician), we will contact the cardiologists via email/phone to VERIFY which group 
they qualify for (exercise/non-exercise). 
D)  Screening at each study visit: Female subjects will be required to take a urine pregnancy 
test before each visit begins. A positive test at anytime will result in exclusion. A Modified 
Allen’s test will be performed on Day 1 for all subjects and during each day when an arterial 
line is placed.  Failing the Modified Allen’s test at anytime will result in exclusion. 
 

 
 
 
 
 
 
 
 
Table 3 
Inclusion 
Exclusion 
Men and women aged 18-80 recruited from patients 
in the surrounding community undergoing PFO/ASD 
closure. Subject’s physician will determine inclusion in 
either exercise or non-exercise group, based on 
available medical information. 
Previous history of coronary artery disease (ischemic 
heart disease such as angina, heart attack, myocardial 
infarction). Failure of Modified Allen’s Test in both 
hands. Currently taking medications or herbal 
supplements for any heart or respiratory disease that 
they cannot stop taking for 48hrs prior to testing 
(seasonal allergy medication not included in exclusion 
medications). Lidocaine, nitroglycerine or heparin 
allergy. Women who are pregnant or trying to become 
pregnant. Previous history of any condition that would 
prevent the subject from performing cycle ergometer 
exercise (for exercise study only). Physician 
determination. PFO/ASD deemed by referring 
physician as not fully closed/endothelialized at 6 
months post-PFO/ASD closure procedure. 
 
4. Compensation: 
Subject Compensation (maximum of $540 for exercise subjects and $330 for NON-exercise 
subjects; paid via check at the end of the study): 
Visit #1 (Exercise Subjects): $25.00: Completing the informed consent and health history 
questionnaire ($5.00) and echocardiographic screening and blood draw ($10.00) will pay 
$15.00. The pulmonary function tests, the diffusion capacity test, and the whole body 
plethysmography or nitrogen washout will pay $10.00. Subjects who choose not to 
participate upon review of the informed consent or are excluded based on any findings 
during this visit will be paid for their degree of visit completion, that is $5.00 if the subject 
decides not to participate after reviewing the informed consent; $ 10.00 for participation in 
the screening procedures; total compensation for reviewing the informed consent and 
participating in screening is $15.00. 

Visit #2 (Exercise Subjects): $35.00: Completing the hypercapnic breathing challenge ($10), 
completing the activity monitor training ($5), completing the six minute walk test ($5) 
completing the VO2max test ($15). 
Visit #3 (Exercise Subjects): $175: Completing the arterial blood line ($100) and exercise 
tests ($75). 
Visit #4a (Exercise Subjects): $30.00: Completing the echocardiographic screening and 
blood draw ($15.00) will pay $15.00. The pulmonary function tests, the diffusion capacity 
test, and the whole body plethysmography or nitrogen washout will pay $15.00. 
Reimbursement for Day 4 is more than Day 1 despite fewer procedures.  This is to 
encourage subjects to return 3 months later. 
Visit #4b (Exercise Subjects): $10.00: Completing the IV blood draw. 
Visit #5a (Exercise Subjects): $35.00: Completing the hypercapnic breathing challenge ($15) 
and completing the six minute walk test ($5) completing the VO2max test ($15).  
Visit #5b (Exercise Subjects): $30.00: Completing the echocardiographic screening and 
blood draw ($15.00) will pay $15.00. The pulmonary function tests, the diffusion capacity 
test, and the whole-body plethysmography or nitrogen washout will pay $15.00. 
Reimbursement for Visit 4 is more than Visit 1 despite fewer procedures.  This is to 
encourage subjects to return 6 months later. 
Visit #6a (Exercise Subjects): $230: Completing the arterial blood line ($130) and exercise 
tests ($100) 
Visit #6b (Exercise Subjects): $35.00: Completing the hypercapnic breathing challenge ($15) 
and completing the six-minute walk test ($5) completing the VO2max test ($15).  
Visit #7a (Exercise Subjects): $10.00: Completing the IV blood draw. 
Visit #7b (Exercise Subjects): $230.00: Completing the arterial blood line ($130) and 
exercise tests ($100) 
NOTE: Reimbursement for Visits 4-7 is more than Visits 1-3 despite fewer procedures.  This 
is to encourage subjects to return 3 or 6 months later for the study. 
Visit #1 (NON-Exercise Subjects): $25.00: Completing the informed consent and health 
history questionnaire ($5.00) and echocardiographic screening and blood draw ($10.00) will 
pay $15.00. The pulmonary function tests, the diffusion capacity test, and the whole body 
plethysmography or nitrogen washout will pay $10.00. Subjects who choose not to 
participate upon review of the informed consent or are excluded based on any findings 
during this visit will be paid for their degree of visit completion, that is $5.00 if the subject 
decides not to participate after reviewing the informed consent; $ 10.00 for participation in 
the screening procedures; total compensation for reviewing the informed consent and 
participating in screening is $15.00. 
Visit #2 (NON-Exercise Subjects): $130.00: Completing the hypercapnic breathing challenge 
($10), completing the activity monitor training ($5), completing arterial line ($100) and 
arterial blood draws breathing room air and 100% O2 ($15). 
Visit #3a (NON-Exercise Subjects): $165.00: Completing the hypercapnic breathing 
challenge ($15), completing arterial line ($130) and arterial blood draws breathing room air 
and 100% O2 ($20). 

Visit #3b (NON-Exercise Subjects): $10.00: Completing the IV blood draw. 
Visit #4a (NON-Exercise Subjects): $10.00: Completing the IV blood draw. 
Visit #4b (NON-Exercise Subjects): $165.00: Completing the hypercapnic breathing 
challenge ($15), completing arterial line ($130) and arterial blood draws breathing room air 
and 100% O2 ($20). 
NOTE: Reimbursement for Day 3/4 is more than Day 2 despite fewer procedures.  This is to 
encourage subjects to return 3 months later. 
Any subject that withdraws (or is withdrawn) before the end of the study will receive 
prorated payment up to the point of completion. 
E. Informed Consent Process 
Informed consent will be administered to each subject by the primary investigator and 
colleagues. 
The primary investigator is well versed in the process of informed consent and has trained 
his co-investigators thoroughly on how to best perform this procedure. The PI will ensure 
that all investigators obtaining consent have experience in the informed consent procedure 
and are capable of adequately discussing the related physiology, study procedure and 
potential risks. 
The researcher will first verbally explain the study in its entirety and in doing so walk 
through the informed consent in person. Subjects will then be given a sufficient length of 
time to read through the informed consent form privately and instructed/encouraged to 
write down or remember any questions/concerns they may have. Afterward, the researcher 
will rejoin the subject and address any question or concern they may have while 
subsequently going back through the informed consent form with the subject and obtaining 
any needed initials and signature at the end of the document. Furthermore, the investigator 
will verbally address any questions the subject may have regarding the seriousness and/or 
likelihood for the occurrence of the risks described in the Informed Consent Form.  The 
research team will address probability and severity of any adverse reactions with the subject 
by carefully explaining the statements regarding probability and severity contained within 
the Informed Consent.  The investigator will also provide appropriate statistics (where 
available) regarding the probability of adverse reactions.  The investigator also advises the 
subject of what he/she can expect to feel during a particular procedure, for example, during 
contrast injection.  Investigator further explains any questions regarding physiology or 
reason for a particular procedure in plain language.  
On the day before ALL visits, the subject will be telephoned or e-mailed (depending on 
preference) to confirm participation and as a reminder to 1) not drink caffeine for 12 hours 
before each study day, 2) not exercise or drink alcohol for 24 hours before each study day 
and 3) not eat for 2 hours before arriving for each study day. Male subjects will be required 
to go shirtless for all studies involving echocardiography. Female subjects will need to wear 
a sports bra for all studies involving echocardiography. To minimize any risk of 
embarrassment both male and female subjects will be allowed to wear a loose fitting shirt 
(provided by the researchers) that allows the upper body to be covered but also allows for 
imaging of the heart and the placement of small electrodes that record heart rate.  

F. Provisions for Participant Privacy and Data Confidentiality 
Each subject folder will be stored in a locking file cabinet inside the primary investigators 
locking office located in the University of Oregon Cardiopulmonary and Respiratory 
Physiology Lab. This lab is located on the 2nd floor of the Center for Medical Education and 
Research Building at 722 E. 11th St., Eugene, OR 97403. All other computer files associated 
with the subject will be identified only through their unique subject ID and stored on a 
password protected lab computers. The de-identified data will be kept for at least 7 years 
after publication, per NIH guidelines. In the unlikely event the data are not published, they 
will be kept for at least 10 years after collection. This will ensure sufficient time for 
publication after data have been collected considering some trainees take up to 6 years to 
graduate, and often publication does not occur until many years after graduation. 
Each subject will be assigned an ID using a random number code system consisting of three 
to five letters describing the study (e.g., CLOSE) and a random, non-repeating number (1-
1000). This ID will be associated with their unique folder, which will contain all study 
documents and data collected including all associated forms (i.e. informed consent 
document). 
The primary investigator will maintain a subject ID key capable of identifying subject IDs to 
subject names and contact information to provide us with the ability to identify subjects as 
additional questions or research findings arise. This ID key will be kept in a locked filing 
cabinet also within the office of the primary investigator. No contact information will be 
stored with subject data.   
De-identified data may potentially be shared with other investigators for research purposes.  
G. Potential Research Risks or Discomforts to Participants 
Confidentiality: 
If data is lost or stolen, subjects could experience invasion of privacy. To minimize the 
potential invasion of privacy, we are not collecting social security numbers so that the 
potential economic impact is greatly minimized. All of our files will be kept in a locked filing 
cabinet to prevent theft and data will be de-identified. Data acquired on computers will be 
password protected. As such, the probability of the adverse outcomes discussed above is 
low, and the severity is minimal. 
Psychological: 
Male subjects will be required to go shirtless for all echocardiography and exercise studies. 
Female subjects will need to wear a sports bra for all echocardiography and exercise studies. 
Female subjects will be allowed to wear a loose fitting scrub top (provided by the 
researchers) over their sports bra that allows for echocardiographic imaging and EKG 
electrode placement. Accordingly, both male and female subjects could potentially feel 
embarrassed or have modesty issues by being shirtless (males) or when only wearing a 
sports bra (females). To minimize the risk of embarrassment or modesty issues, both male 
and female subjects will be allowed to wear a loose fitting scrub top (provided by the 
researchers) that allows for concealment of upper body but also allows for 
echocardiographic imaging and EKG electrode placement. Female subjects will still be 

allowed to wear the sports bra with the scrub top which will allow for required 
instrumentation, but will also allow the subject to cover up as much as possible for the 
study.  Both males and females may wear sweat pants or shorts, i.e. whatever makes the 
subject comfortable. As such, the probability of the adverse outcomes discussed above is 
low, and the severity is minimal. 
Physiological: 
Pulmonary Function Tests: Risks associated with pulmonary function testing include 
shortness of breath, cough, dizziness, and possible loss of consciousness. To minimize risks, 
the co-investigators will administer all pulmonary function tests and allow subjects to rest 
between measurements.  Lung function testing performed in our lab is a routine assessment 
performed in pulmonary function labs all over the world according to American Thoracic 
Society and European Respiratory Society standards. You can stop the test at any time if you 
feel any of the above symptoms.  The probability and severity of these risks is very low. 
Whole Body Plethysmography: Risks associated with whole body plethysmography include 
shortness of breath, dizziness, and cough. To minimize risks, the co-investigators will 
administer all whole body plethysmography tests and allow subjects to rest between 
measurements.  As with pulmonary function testing, the probability of the adverse 
reactions discussed above is low, and the severity is minimal. 
Nitrogen Washout: There are no risks associated with breathing 100% oxygen for 7-10 
minutes. 
Diffusion Capacity (DLco): Risks associated with the diffusion capacity testing include 
exposure to carbon monoxide (CO), shortness of breath, dizziness, and cough. The 
percentage of CO in the gas being breathed will be 0.3%. Cigarette smoke contains 3% CO or 
ten times the amount of CO that will be breathed. Performing the test 5 times will increase 
the level of CO bound to hemoglobin in the subject’s blood by 3.5%. Normal resting levels of 
CO bound to hemoglobin are less than 3% as a non-smoker. This means that if a subject 
performs 5 tests, their blood levels of CO will increase from 3 to 3.1 %, maximally. The half-
life of CO in blood is between 5 and 6 hr, meaning that blood with 3.1 % CO content to start 
with, would have less than 1% carbon monoxide 15 to 18 hours later.  As such, the 
probability of the adverse reactions discussed above is low, and the severity is minimal.  The 
diffusing capacity test performed in our lab is a routine assessment performed in pulmonary 
function labs all over the world according to American Thoracic Society and European 
Respiratory Society standards. As with the lung function testing, the probability and severity 
of these risks is low. To minimize risks associated with testing diffusion capacity of the lung 
using CO, tests will be performed using a commercially available diffusion gas mixture with 
0.3% CO and each subject will be limited to 3 to 5 single breath tests separated by a 
minimum of 4 min according to ATS/ERS recommendations to minimize exposure to CO. The 
co-investigators will administer all diffusion capacity tests.  
VO2MAX and exercise testing: Subjects will perform a VO2max test where they exercise to 
volitional exhaustion.  Criteria for terminating a VO2 max include achieving: 1) heart rate 
>85% of age-predicted max (220-age), 2) a plateau in oxygen consumption and/or a 
respiratory exchange ratio >1.15; all of these criteria are continuously monitored on our 
metabolic system and 12 lead EKG. This carries the rare risk of dizziness, confusion, nausea, 

fatigue, difficulty breathing, abnormal heart rhythms, stroke, heart attack, and sudden 
death. In subjects less than 35 years old, the risk of sudden death of all causes is estimated 
to be 1 in 133,000 for men (Van Camp et al MSSE 1995).  In this study only 100 of 136 deaths 
with identifiable causes were caused by cardiac events, so this estimate of risk may 
overestimate incidence of cardiac events.  The overall risk of sudden death caused by a 
heart problem for all ages and sexes is estimated to be 1 in 15,000 to 18,000. (Source: 
American College of Sports Medicine - ACSM). As such, the probability of the adverse 
reactions discussed above is low, and the severity is very low (e.g. dizziness) to very high 
(e.g. sudden death). 
Hypercapnia during rebreathing tests: Risks associated with breathing hypercapnia (high 
carbon dioxide) at rest include feeling light-headed, headache, fatigue, dizziness, shortness 
of breath. Subjects will be monitored with a peripheral estimate of arterial oxygen 
saturation using a forehead monitor to ensure you are well oxygenated and we will 
continuously monitor inspired and expired oxygen and carbon dioxide levels.  As such, the 
probability of the adverse reactions discussed above is moderate, and the severity is 
minimal. 
Esophageal temperature probe: Risks associated with placing the esophageal temperature 
probe include nose and throat irritation, gagging sensation and an extremely remote 
theoretical risk of esophageal puncture. As such, the probability of the adverse reactions 
discussed above is low, and the severity is minimal.  In the event subjects cannot tolerate 
the esophageal temperature probe, subjects will swallow an ingestible pill, about the size of 
a multi-vitamin, that is designed for human use (FDA approved) and is accurate to 0.1ºC 
(CoreTemp, HQI Technologies, Inc.).  This pill will be used to measure core body 
temperature at rest and during cycle ergometer exercise. Prior to ingestion the temperature 
pill will be calibrated with an external wireless recording device. This will allow us to 
wirelessly acquire the subjects core temperature when necessary as the temperature pill 
transmits a signal to the external device that will then display the appropriate temperature. 
This pill will harmlessly pass through the subject’s intestinal tract. The pill is not recovered, is 
disposable, and every subject receives a new pill for each study day. The probability and 
severity of risks associated with the temperature pill is very minimal.  
Arterial catheterization:  Risks associated with the radial artery catheter include pain and/or 
bleeding during insertion, vasovagal syncope, and hematoma (collection of blood under the 
skin at the puncture site).  Extremely rare risks usually associated with long-term insertion 
(many days) of an arterial catheter include infection and blood vessel blockage.  If a blood 
vessel blockage were to occur, immediate surgical treatment may be required. Arterial 
catheterization will be performed by a board-certified cardiologist (Dr. Jerold Hawn) while 
the subject is comfortably and safely positioned on a gurney to mitigate the potential risks 
associated with vasovagal syncope.  As such, the probability of the adverse reactions 
discussed above is low, and the severity is moderate.   The Principal Investigator has 
extensive experience using this technique in a research setting. 
Intravenous catheter:  Risks associated with placement of an IV include pain and/or 
bleeding during placement, vasovagal syncope, hematoma (pooling of blood under the skin), 
infection, and vessel blockage. The placement of the IV may cause some discomfort with 
rare bleeding or bruising at the puncture site. It also carries the risk of infection. To mitigate 
risks associated with vasovagal syncope, the subject will be safely positioned upright and 

sitting in an IV chair, and the subject will be continually monitored by Dr. Lovering and/or a 
graduate student. As such, the probability of the adverse reactions discussed above is low, 
and the severity is minimal. Dr. Lovering or a graduate student will place IVs. 
Blood Removal: Risks associated with the removal of blood include an aversion to seeing 
blood that could result in nausea, vasovagal syncope, increased stress, and/or feeling faint. 
To mitigate these potential risks, the subject is continually monitored by Dr. Jerry Hawn 
(arterial line placement) and Andrew Lovering PhD (IV placement) and colleagues. In 
addition, the subject is safely and comfortably positioned on either a gurney or IV chair. In 
this way, the potential risk of vasovagal syncope (i.e., fainting) is mitigated. As such, the 
probability of the adverse reactions discussed above is low, and the severity is minimal. 
Saline Contrast Echocardiography:  The PI has been using saline contrast echocardiography 
since 2003 to detect blood flow through intracardiac and intrapulmonary shunts.  Risks: 
transient dizziness associated with agitated sterile saline injection in patients with cardiac 
shunting. With respect to exercise, the Principal Investigator has >10 years of experience 
using TTSCE in a research setting. In 4 years (2003-2007) at the University of Wisconsin 
Madison, approximately 60 human (male and female) subjects (including 8 subjects with a 
patent foramen ovale) were tested without a single adverse event related to TTSCE. 
Additionally, research done at the University or Oregon between 2008 and 2016 has 
involved >100 subjects using TTSCE at rest and during exercise without incident related to 
the TTSCE. We will use agitated sterile saline without preservatives. Furthermore, we will 
use a minimal volume (3-5 mL) of sterile saline. Dr. Lovering or a graduate student will 
perform saline contrast injections, while Randy Goodman or Eben Futral from PeaceHealth 
will perform echocardiography. Mixed saline (saltwater), either alone or with 5% sugar in 
water has been used to help see the ultrasound pictures (echocardiogram) for over thirty 
years.  Saline contrast bubble injections are routinely used to screen for the presence of a 
patent foramen ovale in the clinic.  The American Society of Echocardiography Guidelines 
(2014) state that “…life threatening reactions are rare (<1 in 10,000)” when using contrast 
injections (including bubbles with protein shells) and The European Association of 
Echocardiography (2009) has stated that “… the evidence shows that contrast 
echocardiography is very safe in clinical practice.” And this includes using stabilized bubbles 
with protein shells and we only use non-stabilized saline contrast bubbles in our lab.  We 
only use a small amount of air mixed with saline, thus the probability of any severe adverse 
reaction is very low. Given the evidence presented above, the probability of the adverse 
reactions discussed above is low.  Although the severity of arterial gas emboli is high, given 
the amount of air used and the short life span of intravascular bubbles of this size, the 
likelihood of the constellation of unfortunate events required for a serious adverse reaction 
to occur is very small. 
Heparin and lidocaine allergy: Both carry the potential risk of eliciting an allergic reaction.  
The risk of developing an allergic reaction to each of these individually or cumulatively is 
very small.  Some symptoms of an allergic reaction include itching, tingling, chest tightness, 
difficulty breathing, nausea, or vomiting.  Subjects will be continuously monitored for each 
of these symptoms. The probability of this risk is very low and severity of these risks is 
moderate. 
Risks for subjects undergoing PFO/ASD closure: Potential risks for subjects undergoing 
PFO/ASD closure are at least equal to the general population as outlined above.  Because 

these subjects have a hole in their heart, which allows for blood to flow across the heart 
without being filtered by pulmonary capillaries, there is an elevated risk for stroke, TIA 
and/or arterial hypoxemia (these are likely the reasons the subjects is getting the PFO/ASD 
closed).  Indeed, the subjects who have been selected for PFO/ASD closure in this study will 
include those with previous history of stroke, TIA and/or exercise-induced arterial 
hypoxemia. The goal of the PFO/ASD closure is to reduce subsequent cerebrovascular 
accidents (stroke & TIA) and/or prevent/minimize exercise-induced arterial hypoxemia.  
Thus, post PFO/ASD closure subjects would have a reduced risk profile that would likely 
resemble those without a PFO/ASD.  
Safety Equipment available in the Cardiopulmonary and Respiratory Physiology 
Laboratory (where all testing and screening will be performed):  Phillips FRx AED, a spare 
AED battery, and spare AED pads, bottled oxygen and face masks, all necessary equipment 
to run ACLS algorithms (suction, masks, breathing bag, etc.) and ACLS drugs such as 
chewable aspirin, and oxygen will be administered as required by AHA and ACLS guidelines.   
Additionally, a standard first aid kit is also available.    
Emergency Procedures:  According to American Heart guidelines, in the event of an adverse 
cardiopulmonary event, we will begin CPR, call 911 (as directed by U of O EH&S), and will 
continue CPR as required until emergency medical personnel arrive.  
Safety Monitoring: Subjects will be given clear instructions that they should notify the 
investigators immediately if they experience any of the above-mentioned risk symptoms.  
During all exercise and recovery procedures, all subjects will be non-invasively and 
continuously monitored for vital signs using: 1) a 12 lead EKG to monitor electrical activity of 
the heart, and 2) a forehead probe to monitor arterial oxygen saturation and heart rate. 
During all other procedures subjects will be visually monitored for any signs of discomfort, 
distress or problems.  During both exercise and resting procedures, the investigators will 
continuously ask the subjects how they are feeling and how they are doing. 
H. Potential Benefits of the Research 
This study will not improve the health of subjects and is only being done to gather 
information. This study will not improve the health of the general subject population. 
Completing the aims of this study will have the benefit of contributing to generalizable 
knowledge. 
I. Investigator Experience 
The PI and colleagues have been performing cardiopulmonary and respiratory physiology 
investigations at rest and during exercise in healthy and diseased populations at the 
University of Oregon for ~10 years. Dr. Lovering’s CV is on file. 
The PI trains all graduate and undergraduate personnel on all laboratory procedures and 
protocols.  Co-investigator Jerry Hawn, MD is a board certified cardiologist who has worked 
with Dr. Lovering’s group for almost 10 years placing radial artery catheters, interpreting 
echoes and providing significant intellectual input to the laboratory group. 
Ultrasound technicians, Randy Goodman, RDCS and Eben Futral, RDCS have worked with Dr. 
Lovering’s group for years as well (Goodman ~10 years; Futral ~5 years).  These two 

registered diagnostic cardiac sonographers (RDCS) have performed thousands of resting and 
stress echoes in patients and research subjects.