Clinical trial NCT01854281: Nitrogen Bubble Detection After Simulated Dives in Divers With PFO and After PFO Closure
Official title: Nitrogen Bubble Detection After Simulated Dives in Divers With PFO and After PFO Closure
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Patent Foramen Ovale
Keywords: Patent foramen ovale
Catheter-based closure
Nitrogen bubbles
Decompression sickness
Lead sponsor: University Hospital, Motol
Sponsor class: OTHER
First posted: 2013-05-15
Enrollment: 47
Sex: ALL
Minimum age (years): 19
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: PROBABILITY_SAMPLE
Study population: Adult scuba divers with either a previously diagnosed patent foramen ovale (PFO) or after a catheter-based PFO closure. Consecutive divers that undergo a simulated dive in hyperbaric chamber will be recruited.

Brief summary: The aim of this study is to determine whether catheter-based closure of patent foramen ovale is effective in preventing paradoxical embolization of nitrogen bubbles after simulated dives.

Detailed description: The aim of this study is to determine whether catheter-based closure of patent foramen ovale (PFO) is effective in preventing paradoxical embolization of nitrogen bubbles after simulated dives.

Ultrasonographic detection of venous and arterial nitrogen bubbles will be performed in divers after surfacing from simulated dives in hyperbaric chambers. Divers will be observed after two different dive profiles - Dive A (dive to 18 m for 80 min bottom time) and dive B (dive to 50 m for 20 min bottom time), both performed according to US Navy Air decompression procedure 1996. For both dives two groups will be compared: Divers with PFO and divers after previous catheter-based closure of PFO.

The study will be observational. Sonographic detection of bubbles will be performed after simulated dives that are part of a training program of the divers. Two different dives, previously documented to generate significant amount of venous nitrogen bubbles, were chosen.

The primary end-point will be a positive transcranial doppler test (defined as one or more bubbles detected either during native breathing or after Valsalva maneuver).

Inclusion criteria are: 1) previously diagnosed PFO or a PFO that has been occluded by a catheter-based procedure, 2) signed informed consent

Exclusion criteria: 1) another dive performed in the preceding 24 hours, 2) another previously diagnosed right-to-left shunt, 3) disagreement to be included in the study

This study will be single-center.

Eligibility criteria: Inclusion Criteria:

1. previously diagnosed PFO or a PFO that has been occluded by a catheter-based procedure
2. signed informed consent

Exclusion criteria:

1. another dive performed in the preceding 24 hours
2. another previously diagnosed right-to-left shunt
3. disagreement to be included in the study

Primary outcomes:
measure: Arterial Nitrogen Bubbles After Surfacing
timeFrame: assesed within 1 hour after surfacing
Secondary outcomes:
Other outcomes:
Locations:
city: Prague
country: Czech Republic
facility: Department of Cardiology, University Hospital Motol
Study officials:
affiliation: Department of Cardiology, UH Motol
name: Josef Veselka, MD, PhD
role: STUDY_CHAIR
affiliation: Department of cardiology, UH Motol
name: Jakub Honek, MD
role: STUDY_DIRECTOR
References:
citation: Honek J, Sramek M, Sefc L, Januska J, Fiedler J, Horvath M, Tomek A, Novotny S, Honek T, Veselka J. Effect of catheter-based patent foramen ovale closure on the occurrence of arterial bubbles in scuba divers. JACC Cardiovasc Interv. 2014 Apr;7(4):403-8. doi: 10.1016/j.jcin.2013.12.199. Epub 2014 Mar 14.