PFO (Patent foramen ovale) is an opening in the wall of the heart which did not close completely after birth (opening required before birth for transfer of oxygenated blood via the umbilical cord). This opening can cause a shunt of blood from right to left , but more often there is a movement of blood from the left side of the heart (high pressure) to the right side of the heart (low pressure).
People with shunts are less likely to develop fainting or low blood pressure with diving than are obstructive valve lesions (such as mitral valve stenosis or aortic stenosis), but are more likely to develop fluid accumulation in the lungs from heart failure and severe shortness of breath from the effects of combined exercise and water immersion.
Ordinarily, the left to right shunt will cause no problem; the right to left shunt, if large enough, will cause low arterial O2 tension (hypoxia) and severely limited exercise capacity. In divers there is the risk of paradoxical embolism of gas bubbles (passage of bubbles into the arterial circulation) which occur in just about all divers in the venous circulation during decompression.
Blood can flow in both directions with Intra-atrial shunts at various phases of the cardiac cycle and some experts feel that a large atrial septal defect (PFO) is a contra-indication to diving. In addition, a Valsalva maneuver, used by most divers to equalize their ears during descents and ascents, can increase venous atrial pressure to the point that it forces blood containing bubbles across the PFO into the arterial circulation. Thus the usual filtering process of the lungs is by-passed.
I have been diving since 1988 and have been working and diving in the industry for well over 16 years.
Having a low breathing rate, At this time, I had a breathing rate of approximately 5-8 breaths per minute. I also used to get headaches regularly on the surface, and felt that post-diving headaches were not unusual. I am also a migraine sufferer and have had them since I was a small child
I am now around 5 weeks post PFO closure and while it was not as easy as i thought it would be, I am finally feeling much better and getting my energy back. No matter what the doctors say I am convinced that it takes at least 5 - 6 weeks recovery time if not more. I devloped an irratic heart beat which is now being sorted this was a reaction to the procedure.
I am also a migraine sufferer and have had them since I was a small child. However the reason they found my PFO was because I dive and have had lots of unexplained symptoms. I did not want to live with the high risk of a stroke or a heart attach and not dive again. I figure 6+ weeks of discomfort is well worth a lifetime of remaining alive and able to dive. I have had zero migraines or headaches since the procedure!
Let me know if you have any specific questions I can help you with.