SECTION I: BACKGROUND AND ANATOMY -- Historical perspective and importance of PFO.- Embryology, Neonatal Circulation and Anatomy of PFO -- Anatomical variations of Patent Foramen Ovale -- Aging and Patent Foramen Ovale -- SECTION II: METHODS AND TECHNIQUES FOR DETECTION AND CHARACTERIZATION OF PFO -- Echocardiographic detection and transcranial Doppler quantification of right-to-left shunting -- ICE: intra-procedural evaluation and guidance during closure of PFO -- A Comparison of Methods to Detect and Quantitative PFO: TCD, TTE, ICE and TEE -- Angiographic evaluation for PFO and Pulmonary AVMs -- SECTION III: PFO AND CLINICAL SYNDROMES -- An Overview of Clinical Syndromes (Keeping The Heart In Mind) -- The Association of Patent Foramen Ovale and Migraine Headache -- Current Patient Management Issues, Clinical Trial Design Challenges and the Pathway Forward.- Patent foramen ovale and divers -- Orthodeoxia and Platypnea -- Obstructive Sleep Apnea and Patent Foramen Ovale -- PFO and Various Types of Surgery.- When a PFO is Discovered Incidentally -- SECTION IV: CLOSURE METHODS -- The GORE Septal Occluder -- The novel PFO specific closure devices: Why did they fail? -- Optimal device for children and closure indications in pediatric population -- Occlutech, PFM, Lifetech and other new devices. What's on the horizon? -- Complications of PFO Closure -- SECTION V: STATISTICAL METHODS, TRIALS AND TRIBULATIONS -- Device Closure of Patent Foramen Ovale or Medical Therapy for Cryptogenic Stroke: The CLOSURE I Trial -- The Gore REDUCE Clinical Study -- The PC Trial: An Effective Treatment Not Demonstrating Effective Power -- From FDAs point of view: What is needed to move PFO closure for stroke prevention forward? -- The Medical Device Manufacturer's Perspective - W.L. Gore & Associates, Inc -- PFO-Patient's Perspective -- Clinical Trials to Assess the Relationship between Patent Foramen Ovale and Migraine Headaches -- Do We Need More PFO Trials: Hypercoaguable Syndromes,Obstructive Sleep Apnea, and Arrhythmias -- SECTION VI: DIFFICULTIES/OBSTACLES IN STARTING PFO CLOSURE PRACTICE -- Obstacles in Starting a PFO Closure Program. How I Did It -- Developing a successful integrated PFO closure program.