If you suspect a PFO, it might also be a condition in which the flap opens briefly causing a shunt. In addition to previous advice, you may want to try to restrain from exertion when getting out of the water such as climbing boat ladders or walking up hill. When possible, spend a few extra minutes on the tag line or surface resting before exiting. This might give you time to take advantage of the "surface deco stop," hand up or remove any additional heavy gear like cameras, goody bags, fins, even your tank, and climb out strong and light. If your condition worsens and you consider giving up scuba, freediving is a healthy and relaxing way to enjoy the underwater world and many people enjoy it far more than when using scuba.