Does Patent Foramen Ovale Size Matter in Men and Women
Conditions: Patent Foramen Ovale
Sponsor: University of Oregon

Does Patent Foramen Ovale Size Matter in Men and Women 
 
NCT #: Not Assigned 
 
Dec 12, 2018 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Study Title: Does patent foramen ovale size matter in men and women? 
Protocol Number: 04302018.049 
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 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 our 
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, we were curious 
as to whether there would be a sex effect, but due to logistical constraints, we were 
unable to recruit an equal number of female and male subjects. Thus, in addition to 
the potential size effect on our outcome measures, we 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. Our 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. 

B. Specific Aims/Study Objectives 
The overarching goal of this study is to examine how cardiopulmonary and respiratory 
physiology may be altered by the size of a PFO and/or biological sex. 
To do this, 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 and six-minute walk test. 
3) Quantify QIPAVA at rest. 
4) Quantify plasma inflammatory markers (TNFα, IL-1, 6 & CRP)  
5) Quantify core body temperature 
Hypotheses: We hypothesize that those individuals with a large PFO will display worse 
pulmonary gas exchange efficiency, compared to those with a small or no PFO; there will 
not be a sex effect. A large PFO, when compared to a small or no PFO, will be associated 
with increased plasma inflammatory mediators, and will result in a higher core body 
temperature.  
C. Methods, Materials and Analysis 
This study will be performed over the course of 3 days at the Cardiopulmonary and 
Respiratory Physiology Lab at the University of Oregon.  
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 the day when an arterial line is placed (Day 3).  Failing the Modified Allen’s 
test at anytime will result in exclusion. 
Description of Study Days 
Day 1 (~ 2 hours) 
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 and IPAVA will be graded using saline 
contrast echocardiography while the subject is breathing room air (PFO and IPAVA 
blood flow) and breathing 100% O2 (PFO 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) 
Day 2 (~ 1 hour) 
Subjects will perform a 6 minute walk test (~15 min) 
Subjects will perform a VO2max test (~30 min) 
Day 3 (~ 3.5 hours) 
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 at standardized workloads of 70, 100, 130 
and 160 Watts (W) for 3 minutes each, followed by 15 W/min increments until 
VO2Max is reached. This will be done with subjects breathing room air (~1.5hr) 
After exercise breathing room air, subjects will take a 30-minute break. (~30min) 
Subject will repeat the exercise protocol above while breathing 55% 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. 
Description of Study Day Procedures 
Modified Allen’s Test: 
This test examines collateral blood flow in the hand, and is performed on the day 
there is an arterial line placed. The subject clenches their hand 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: 
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.  This will be repeated while breathing 100% O2 for 10 minutes. Subjects will 
be asked to perform a Valsalva maneuver while breathing room air and 100% O2. A 
Valsalva maneuver is performed by completing a moderately forceful exhalation 
against a closed glottis aka ‘bearing down.’ This maneuver enhances blood flow 
across the PFO. Multiple saline contrast injections (up to 3) may be performed to 
verify bubble grades/presence of a PFO. 
Pulmonary Function Tests: 

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. 
 
Diffusion Capacity (DLCO): 
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: 
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: 
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): 
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): 
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. 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 BioLegend’s 
LEGENDplex immunoassay. Total IV blood draw is approximately 21 mL. 
VO2MAX test and 6 minute walk test:  
The six minute walk test will be performed on the second floor of the Center for 
Medical Education and Research. The subjects begins walking laps around a 
continuous hallway for six minutes. One lab of the hallway is measured using a 
roller-wheel measuring tape. The number of laps completed by the subject is 
recorded, and the total distance is then calculated. 
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 (50 Watts), 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: 
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). 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 Subjects (i.e., IV + Arterial Line) will be less than 
250 mL.  
Exercise with arterial line:  
After arterial line placement (see above) the subjects will perform two bouts of 
graded exercise tests on the cycle ergometer at standardized workload stages of 70, 
100, 130 and 160 W with each stage lasting 3 minutes, followed by 15W/min 
increments until VO2Max is reached.  During one bout, subjects will breathe normal 
oxygen levels (21% oxygen), during the other bout, subjects will breathe high oxygen 
levels (55% oxygen).  Bouts will be randomized and separated by 30 minutes of rest 
breathing room air.  

Intrapulmonary & intracardiac Shunting with arterial line placement: 
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: 
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.  
D. Research Population & Recruitment Methods & Compensation 
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, TNFα 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, we 
determined that n = 15 individuals would be sufficient to test our hypotheses. Thus, 
we are asking to recruit 45 subjects (sex of these subjects may be chosen specifically 
to ensure even distribution of subjects in order to appropriately analyze the effect of 
sex on our outcome measures) 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 males and females, 
and between those with a small or no PFO compared to a large PFO will be analyzed 

using a mixed analysis of covariance (MANCOVA). Mean differences in VO2MAX, 6 
minute walk test, inflammatory markers between males and females, and between 
those with a small or no PFO compared to a large PFO will be analyzed using an 
unpaired t-test.  
The population of subjects will include males and females between the ages of 18-40 
and will be recruited via subject fliers. In addition, subjects known to have or not 
have a PFO based on previous participation in studies in the Cardiopulmonary and 
Respiratory Physiology Lab at the University of Oregon may be contacted to evaluate 
whether they would be interested in participating in this study. 
Subject fliers, initial phone script and email script are attached. 
 
Detailed Recruitment Information 
A) Once a subject contacts us (via flier) or is contacted by us (via previous study 
participation) we will use the phone script (attached) to determine their eligibility. 
The phone script is the first instance where the subject will be informed about 
restrictions regarding caffeine/alcohol/food and medications. 
B) 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 day when an arterial line is placed (Day 3).  Failing the Modified Allen’s test 
at anytime will result in exclusion. 
C) Two days before the first visit, 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 the study day and 3) not eat for 2 hours before arriving for the study day 
and 4) to stop taking medications or herbal supplements for 48 hours before the study 
visit (as determined by their referring physician). Male subjects will be required to go 
shirtless for echocardiography. Female subjects will need to wear a sports bra for 
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.  
D) Subjects may be either referred to us by a flier, OR, we may contact subjects who 
have previously enrolled in studies in our lab. Thus, to verify that it is safe for 
subjects to refrain from taking medications 48 hours prior to the study day, we will 
contact the associated physician to determine whether or not this is appropriate.  
 
Table 1 
Inclusion 
Exclusion 

Inclusion 
Exclusion 
Men and women aged 18-40 recruited from 
subjects in the surrounding community, as 
well as individuals who have previously 
participated in research studies in the 
Cardiopulmonary and Respiratory Physiology 
Lab at the University of Oregon who are 
known to have/not have a PFO. Specifically, 
we are looking to recruit 6 male and 9 female 
subjects, have them fully participate in the 
study, and then we will be able to 
appropriately analyze the effect of biological 
sex on our outcome variables. It may be the 
case where we end up recruiting more 
subjects, if for example other exclusionary 
criteria are met. 
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). Because we are looking 
to recruit enough male (6) and female (9) 
subjects to fill in data from our preliminary 
work, if (for example) we reach the point 
where we have recruited and studied 9 female 
subjects, the next female who may be 
interested in participating may end up being 
excluded. This is to ensure we have an even 
number of male/female subjects to 
appropriately test the potential effect of 
biological sex on our outcome measures. 
Recreational drug use. 
 
Compensation 
Subject Compensation (maximum of $220: 
Visit #1: $25: Completing the informed consent and health history questionnaire 
($5.00) and echocardiographic screening and blood draw ($10.00) will pay $15.00 
total. 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.  
Visit #2: $20: Completing the six minute walk test ($5) completing the VO2max test 
($15). 
Visit #3: $175: Completing the arterial blood line ($100) and exercise tests ($75). 

Any subject that withdraws (or is withdrawn) before the end of the study will receive 
prorated payment up to the point of completion. 
 
The following table is meant to assist as a screenshot of what tests are conducted on each 
of the three study days, as well as shown the compensation for each test. 
Table 2  
Visits: 
1 
2 
3 
Days 
x 
x 
x 
Study Procedures: 
  
  
  
IC & Health Hx, HIPAA form 
x 
Modified Allen Test 
x 
x 
Comprehensive Screening 
x 
Pulmonary Function 
x 
Diffusing Capacity 
x 
Plethysmography 
x 
Nitrogen Washout* 
x 
Transthoracic Saline Contrast Echo (TTSCE) 
x 
x 
Intravenous catheter (IV) 
x 
x 
VO2Max & 6 min walk 
x 
Arterial Blood Gas Measurement 
x 
Exercise w/arterial line 
x 
Intrapulmonary/intracardiac shunt w/art line 
x 
Core Body Temp 
x 
Compensation: 
  
  
  
IC & Health Hx 
5 
Echo screen/blood draw 
10 
PFT, diff capacity, plethysmography 
10 
six min walk 
5 
vo2max 
15 
arterial line 
100 
exercise tests 
75 
blood draws/breathing room air 
Total for completed study visit 
25 20 175 
Total for all aspects of the study 
 
220 
 
 
 

 
Click here to enter text. 
 
E. Informed Consent Process 
Once a subject contacts our lab, OR we contact an individual who has previously 
participated in our studies, we will use the phone script to determine whether or not 
that subject would be eligible for the study (see phone script document for the five 
exclusionary questions). That being said, no participant identifiable data will be 
obtained. It is merely used as a pre-screening tool to determine if the subject would fit 
the inclusion/exclusion criteria.  
Informed consent will be administered to each subject by the primary investigator and 
colleagues. During the initial meeting where we will attain informed consent, the 
subject will be provided with the document entitled ‘PFO Fill HIPAA.’ The primary 
investigator and colleagues will verbally explain this document, and answer any 
questions the subject has. Detailed inclusion/exclusion criteria will be discussed with 
the subject. 
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.  

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., FILL) 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). This ID will also be used to label subject blood 
samples, which will be centrifuged, and the de-identified plasma will be stored at -80 
degrees C until assayed. The remaining sample (not plasma) will be discarded into a 
biohazard waste container and will be collected and destroyed by the Environmental 
Hazard and Safety Department at the University of Oregon. 
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. 
If the subject, upon their first visit does not qualify for the study (see Table 1 above), 
any subject information will be immediately destroyed. Thus, if the subject does not 
consent to participate AND/OR they fail the screening procedures, the individually 
identifiable PHI obtained for recruitment will be destroyed. 
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 echocardiography and the VO2Max 
test. Female subjects will need to wear a sports bra for echocardiography and the 
VO2Max test. 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.  
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.  
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). 
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 
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. 
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. 
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.