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Effect of body position and hypoxia on the recruitment of the patent foramen ovale
Author(s) -
Moses Kayla,
Bates Melissa,
Beshish Arij,
Pegelow David,
Eldridge Marlowe
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1054.14
Subject(s) - patent foramen ovale , supine position , medicine , cardiology , hypoxia (environmental) , body position , right to left shunt , intracardiac injection , anesthesia , oxygen , physical medicine and rehabilitation , chemistry , organic chemistry , migraine
The patent foramen ovale (PFO) is a recruitable intracardiac shunt between the right and left atrium. We aimed to determine if body position and oxygen tension affect blood flow through the PFO in healthy adults. We hypothesized that hypoxia and body positions that promote right atrial filling would independently recruit the PFO. Subjects with (n=3) a PFO performed 11 trials, combining four different O 2 levels (100, 21, 15, or 10%) and three positions (upright, supine, and 45° head down), with the exception of 10% O 2 while 45° head down. After five minutes in each position, breathing the prescribed oxygen tension, saline bubbles were injected into an antecubital vein and a four‐chamber echocardiogram was obtained. Bubble density passing through the PFO was quantified using a 0–5 scale. We found that changes in oxygen tension and body position had little independent effect on PFO recruitment (2±1). However, PFO recruitment increased when breathing 15 and 10% O 2 in the supine position (3±1). This suggests that the combination of hypoxia and position may increase right atrial pressure, increasing right‐to‐left shunting across a PFO. We expected that elevated right atrial pressure would cause PFO recruitment to be greatest in the head down position while breathing hypoxia, but were surprised to find no effect (1±1). We plan to continue these studies and further investigate these unanticipated findings.