Patent Foramen Ovale

How big of a problem is it to have a patent foramen ovale? 
The foramen ovale is an opening that exists between the right and left atria, the two upper chambers of the heart. During the fetal period, this communication is necessary for blood to bypass the circulation of the lungs (since there is no air in the lungs at this time) and go directly to the rest of the body. Within the first few days of life, this opening seals over, ending the link between these heart chambers. In approximately 25-30 percent of individuals, this communication persists as a small opening, called a patent foramen ovale (PFO).

A PFO may be very small, physiologically insignificant, or it may be larger and occasionally a route for the bypass or shunting of blood. Usually, because the pressure in the left atrium exceeds that in the right atrium, no blood crosses the PFO (when patent, or open, there is still a flap of tissue in the left atrium that overlies the opening of the PFO).

 
Fitness and Diving Issue
As in the case of atrial and ventricular septal defects, under certain circumstances, a PFO can result in shunting of blood from the right side of the heart to the left side. This is much more likely to occur in the atria than the ventricles because of the pressure differences between the chambers. Innocuous bubbles that may develop in the venous side of the circulation after a dive may be shunted to the left side of the heart and then distributed through the arteries. The result is that a paradoxical gas embolism or severe decompression sickness can result from a seemingly innocent dive profile.

Studies of divers with severe decompression sickness have shown a rate of patent foramen ovale higher than that observed in the general population. Special Doppler bubble contrast studies can identify a PFO. The diver with a known PFO should know the potential increased risk of decompression illness. A diver with a PFO who has suffered an embolism or serious decompression sickness after a low-risk dive profile should likely refrain from future diving.

At present, most diving physicians agree that the risk of a problem associated with a PFO is not significant enough to warrant widespread screening of all divers. An episode of severe decompression illness that is not explained by the dive profile should initiate an evaluation for the existence of a PFO.

For more information on cardiovascular conditions, see the complete article by Dr. James L. Caruso on Cardiovascular Fitness and Diving from the July/August 1999 issue of Alert Diver.
Posted in

No Comments


Categories

 2018
 2016
After anaesthesia Air Quality Air exchange centre Altitude changes Altitude sickness Ama divers Anaerobic Metabolism Annual renewal Apnea Apnoea Arterial gas embolism Arthroscopic surgery Aurel hygiene BCD Badages Bag valve mask Bandaids Barbell back squat Bench press Blood flow Bouyancy compensators Boyle's Law Boyle\'s Law Bradycardia Brain Breast Cancer Breath Hold Diving Breath hold Breath-hold Breathing Gas Breathing Bruising Buoyancy Burnshield CGASA CMAS CO2 Cabin pressure Camera settings Cancer Remission Cancer treatments Cancer Cannabis and diving Cannabis Cape Town Dive Festival Carbon dioxide Cardio health Cardiomyopathy Charles' Law Charles\' Law Charles\\\' Law Charles\\\\\\\' Law Charles\\\\\\\\\\\\\\\' Law Chemotherapy Coastalexcursion Cold Water Cold care Cold Compressed gas Conservation Contaminants Contaminated air Corals Courtactions Crohns disease Cutaneous decompression DAN Courses DAN Profile DAN Researchers DAN medics DAN report DCI DCS Decompressions sickness DCS DM training DReams Dalton's Law Dalton\'s Law Dalton\\\'s Law Dalton\\\\\\\'s Law Dalton\\\\\\\\\\\\\\\'s Law Deco dives Decompression Illness Decompression Sickness Decompression illsnes Decompression Diseases Dive Chamber Dive Instruction Dive Instructor Dive Pros Dive Research Dive Training Dive accidents Dive buddies Dive computers Dive gear Dive health Dive medicines Dive medicine Dive safety Dive staff Diveleader training Diveleaders Diver Profile Divers Alert Diving Kids Diving career Diving emergencies Diving guidelines Diving injuries Diving suspended Diving Domestic Donation Dr Rob Schneider Drysuit diving Drysuit valves Drysuits EAP Ear pressure Ear wax Ears injuries Education Emergency decompression Emergency plans Emergency underwater Oxygen Recompression Environmental factors Environmental impact Equipment care Exercise Extended divetime Extreme treatments Eye injuries FAQ Fatigue Fire Coral First Aid Equipment First Aid Training First Aid kits Fish Fitness Flying Francois Burman Free diving Free flow Freedive Training Freediver Freediving performance Gas Density Gas laws Gas mixes GasPerformance Gastric bypass Gordon Hiles HELP HIRA Haemorhoid treatment Hazardous Marine life Health practitioner Heart Health Heart Helium High temperatures Hot Humans Hydrate Hydrogen Hydroids Hydrostatic pressure Hyperbaric Chamber Hyperbaric research Hypothermia Immine systems In Water Recompression Indemnity form Indian Ocean Inert gas Infections Instinct Instructors Insurance Integrated Physiology International travel International Irritation Kidneys Kids scubadiver Labour laws Legal advice Legislation Leukemis Liability Risks Liability releases Liability Life expectancy Lifestyle Low blood pressure Low volume masks Lung function Lung injuries Lung MOD Maintenance Mammalian Dive Response Mammalian effect Master scuba diver Maximum operating depth Medical Q Medical questionaire Medical statement Middle ear pressure Mike Bartick Military front press Mixed Gas Mono Fins Mooring lines More pressure Muscle pain Mycobacterium marinum Nautilus Nitrogen build up Nitrox No-decompression Non-rebreather Mask Normal Air Nosebleeds O2 providers O2 servicing OOxygen maintenance Ocean pollution Orbital implants Oronasal mask Oxygen Cylinder Oxygen Units Oxygen deficit Oxygen deicit Oxygen ears Oxygen equipment Oxygen masks Oxygen supply Oxygen therapy Oxygen P J Prinsloo PFI PJP Tech Part 3 Photography Plastic Pneumothorax Pool Diving Press Release Provider course Pulmanologist Pulmonary Bleb Purge RAID South Africa Radio communications Rashes Recompression Regulator Remote areas Report incidents Rescue training Resume diving Risk assesments SABS 019 Safety Stop Safety Saturation Diving Save our seas Science Scuba Air Quality Scuba Injury Scuba children Scuba dive Scuba health Scubalearners Sealife Skin Bends Skin outbreak Skin rash Snorkeling Snorkels Sodwana Bay Splits Squeezes Supplemental oxygen Surgeries Surgery Tattoes Technical Diving The Bends The truth Thermal Notions Tides Tips and trick Transplants Travel tips Travel Tweezers Unconsciousness Underwater photographer Underwater pho Vaccines Vagus nerve Valsalva manoeuvers Vape Vaping Vasvagal Syncope Venting Washout treatments Water Weakness Wetsuit fitting White balance Winter Woman in diving Work of Breathing Wound dressings Wreck dive Wreckdiving Youth diver abrasion air-cushioned alert diver altitude anemia antibiotics antiseptics bandages bent-over barbell rows body art breathing air calories burn cardiovascular checklist chemo port child clearances closed circuit scuba currents cuts dead lift decompression algorithms decongestants dehydration dive injuries dive medicing dive ready child dive reflex dive tribe diver rescue diver training dive diving attraction doctors domestic travel dri-suits dry mucous membranes dry suits dry e-cigarettes ear spaces elearning electrolyte imbalance electroytes emergency action plans emergency assessment equalizing exposure injuries eyes fEMAL DIVERS flexible tubing frediving gas bubble health hospital humidity immersion pulmonary edema (IPE join DAN knee longevity lower stress marine pathogens medical issues medical procedures medical risk assesment mental challenge minor illness mucous membranes nasal steroids nasal nematocysts newdivers nitrogen bubbles off-gassed operating theatre operations orthopeadic outgas pain perforation phillippines physical challenges pinched nerves plasters post dive preserve rebreather mask rebreathers retinal detachment risk areas safety stops saturation scissors scuba equipment scuba single use sinus infections smoking snorkeling. spearfishing stings strength sub-aquatic swimmers ears tattoo care tecnical diver thermal protection training trimix unified standards vision impaired warmers water quality