Nitrogen Bubble Detection After Simulated Dives in Divers With PFO and After PFO Closure

University Hospital, Motol

Status: Completed

Conditions: Patent Foramen Ovale

Study type: Observational

Funder types: Other

Identifiers

NCT01854281

EK-1929/12

Details and patient eligibility

About

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.

Full 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.

Enrollment: 47 patients

Sex: All

Ages: 19+ years old

Volunteers: No Healthy Volunteers

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

Trial design

47 participants in 4 patient groups

Patent foramen ovale dive A group

Description:

Divers with a previously diagnosed patent foramen ovale observed after Dive A.

Closure dive A group

Description:

Divers with a patent foramen ovale previously closed by a catheter-based procedure observed after Dive A.

patent foramen ovale dive B group

Description:

Divers with a previously diagnosed patent foramen ovale observed after Dive B.

closure dive B group

Description:

Divers with a patent foramen ovale previously closed by a catheter-based procedure observed after Dive B.