Oral Positive Pressure Device (oPEP) Effect on Flow Pulsatility in the Fontan Circuit
Phase: NA
Conditions: Single-ventricle
Sponsor: Tarek Alsaied

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Study Protocol  
 
 
 
 
 
 
Official Title: Simple Non-invasive Breathing Device to Improve Pulmonary Flow Pusatility in 
Single Ventricle Post Fontan 
  
 
 
ClinicalTrials.gov ID (NCT number): STUDY22050151 
 
 
 
Protocol Date: 1/1/24 
 
 
 
 

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Scientific Background 
By replicating biphasic ventilation's benefits, Sniff-PEP breathing may prove to improve 
outcomes in Fontan patients. This research will furnish preliminary data encompassing CMR, 
biomarker studies, and QoL analyses on Sniff-PEP breathing's effects. With our multidisciplinary 
team's expertise, we are well-equipped to evaluate this promising intervention, laying the 
groundwork for broader, multi-institutional research endeavors. 
 
 
 
 
 
 
 
Study Objectives 
A. Specific Aims 
 
Aim #1: To evaluate the acute effects of oPEP in Fontan patients undergoing clinically 
indicated echocardiogram 
 
 
Hypothesis: oPEP use in Fontan patients will increase flow pulsatility in 
the inferior vena cava, hepatic veins, Fontan circuit and pulmonary 
arteries that will ultimately lead to increased cardiac output 
 
Aim #2: To evaluate the effects of one month use oPEP in Fontan patients undergoing 
clinically indicated echocardiogram 
 
 
Hypothesis: oPEP use in Fontan patients for a month will increase flow 
pulsatility in the inferior vena cava, hepatic veins, Fontan circuit and 
pulmonary arteries that will ultimately lead to increased cardiac output 
 
 
 
 
 
 
 
Study Design & Methods 
 
 

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Dr. Shaji will be screening pediatric cardiology patients who will be having their 
appointments in the Lawrenceville locations. Of those patients who meet inclusion 
criteria, either he, Dr. Alsaied, or another appointed official will approach the patient 
and/or their guardians and discuss the study with them and provide them information. 
If they agree to participate in the study, then a demonstration will be done for the 
subject on how to use the device appropriately. The subject will be given their own 
personal device and will practice the breathing technique for the device. This device has 
been catalogued, never been used by another person, and sanitized. The patient will 
place the device between their lips and create a tight seal. Then, they will start by 
inhaling through their nose and exhaling through their mouth through the device. The 
subject will practice till they feel comfortable with the breathing maneuver. An initial 
research quality of life questionnaire will be given to the subject and their guardians for 
completion. Subject then will have his standard clinic echocardiogram. After completion 
of the standard echocardiogram protocol, the subject will perform the breathing 
exercise through the device. While breathing through the device, we will obtain 
echocardiogram measurements as detailed below:  
 
a. 
Subcostal sagittal 
i. 
Color Doppler of IVC and hepatic veins 
ii. 
Pulse wave Doppler of IVC (distal to hepatic veins) 
iii. 
Pulse wave Doppler of hepatic vein 
 
b. 
Apical view 
i. 
2D of systemic outflow tract 
ii. 
Color Doppler of systemic outflow tract 
iii. 
Pulse wave Doppler of systemic outflow tract Doppler  
iv. 
Continuous wave Doppler of neoaortic valve 
 
c. 
Suprasternal coronal Notch view  
i. 
If possible, 2D of SVC and RPA/LPA junction 
ii. 
Color Doppler of SVC and RPA/LPA junction 
iii. 
Pulse wave Doppler of SVC, RPA, and LPA 
 
d. 
(if LPA not well seen in suprasternal coronal) Suprasternal sagittal view 
i. 
Color Doppler of LPA 
ii. 
Pulse wave Doppler of LPA 
 
These echo measurements will then be confirmed or read by a cardiologist who will be 
blinded against the condition the patient is in (normal breathing vs breathing through 
oPEP). 20% of the measurements will be confirmed by another reader.  
 
The patient will complete a brief questionnaire at baseline. We will instruct the patient 
to use the device 3-4 times daily for a duration of 10-15 minutes. After a period of 

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approximately 4 weeks, the patient will return to the Lawrenceville location and will 
have a repeat echocardiogram according to the protocol below:  
a. 
Subcostal sagittal 
iii. 
Color Doppler of IVC and hepatic veins 
iv. 
Pulse wave Doppler of IVC (distal to hepatic veins) 
v. 
Pulse wave Doppler of hepatic vein 
 
b. 
Apical view 
vi. 
2D of systemic outflow tract 
vii. 
Color Doppler of systemic outflow tract 
viii. 
Pulse wave Doppler of systemic outflow tract Doppler  
ix. 
Continuous wave Doppler of neoaortic valve 
 
c. 
Suprasternal coronal Notch view  
x. 
If possible, 2D of SVC and RPA/LPA junction 
xi. 
Color Doppler of SVC and RPA/LPA junction 
xii. 
Pulse wave Doppler of SVC, RPA, and LPA 
 
d. 
(if LPA not well seen in suprasternal coronal) Suprasternal sagittal view 
xiii. 
Color Doppler of LPA 
xiv. 
Pulse wave Doppler of LPA 
 
These echo measurements will again be confirmed or read by a cardiologist who will be 
blinded against the condition the patient is in (normal breathing vs breathing through 
oPEP). 20% of the measurements will be confirmed by another reader.  
At this point, the subject and guardian will be given a follow up questionnaire and we 
will leave them with the device for their personal use if they choose to keep it. 
Otherwise, we will accept the returned device, catalogue return, and will disposed in an 
appropriate manner.  
 
 
 
 
Eligibility Criteria  
Inclusion Criteria:  
- Patients with single ventricle with Fontan palliation 
- Over the age of 8 years who would be cooperative with breathing through the oPEP 
device 
 
Exclusion Criteria:  
- Patients with Fontan palliation under the age of 8 years 
- Patients who have interrupted inferior vena cava 

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- Patients with abnormal pulmonary artery anatomy 
 
 
 
 
 
 
Statistical Considerations 
The pulmonary pulsatility index, hepatic vein and portal vein pulsatility index, aortic 
valve VTI will be compared before and at the time of using the oPEP device. A repeated 
t-test will be used for within subject comparison. Since this is a pilot study we will plan 
to include 15 patients.