This book is the ultimate reference on patent foramen ovale (PFO), a defect in the septum of the heart estimated to be present in more than twenty percent of the adult population and a proven cause of systemic embolism. All chapters have been written by internationally recognized experts in the field and cover PFO genetics and anatomy in addition to the effect PFO can have on various different organs and its supposed involvement in several conditions and clinical syndromes such as migraine, diving incidence, platynea orthodeoxia, economy class syndrome, sleep apnea and persistent desaturations in mild right ventricular dysfunction. As PFO anatomy varies significantly between individuals, chapters have also been included on the diagnostic tools, methods and techniques for appropriate assessment, detection and characterization of PFO. Furthermore, the multitude of available closure devices and techniques for PFO closure are discussed together with current and ongoing trial data. The book concludes with guidance and instruction on establishing a successful PFO program. Patent Foramen Ovale will be an essential text for the whole adult and pediatric interventional community, general cardiologists, internists, primary care physicians, neurologists and device companies in addition to medical students, graduate students and fellows in training.