Atrial Septal Defects

What's an atrial septal defect and how does it affect diving?
An atrial septal defect (ASD) results from the incomplete closing of the wall that separates the right and left atria (the two upper chambers of the heart) during embryonic development. This is not an uncommon phenomenon in the general population, and, if the hole is small enough, the average person will experience minimal physiologic consequences. Women are affected more commonly than men.

Surgical correction of the defect may be undertaken, especially if the person is experiencing symptoms secondary to blood flowing from the normally higher pressure left atrium to the right atrium. Early in life, symptoms may be few, but over a period of years, complications, such as abnormal heart beats and shunting (bypassing) of blood from left to right may occur.

On examination, the person with an ASD may have a significant murmur.

Fitness and Diving Issue: While the normal pressures in the chambers of the heart favor blood flowing from left to right through an ASD and VSD, periods in which this flow is reversed can occur, particularly for ASD. Although individual variations exist, Doppler studies have shown that most divers will have venous bubbles after a dive of significant depth and bottom time. These usually pose no significant threat, and the diver remains symptom-free.

Having a defect that allows bubbles to cross from the right side of the heart to the left is a whole different matter, however: once in the left side of the heart, bubbles may then be transported through the arteries to areas of the body where they can do some harm (e.g., to the brain, kidneys, and spinal cord). Several studies have demonstrated that the number of ASD’s (and other defects in the wall separating the right and left sides of the heart) in divers treated for decompression illness was higher than expected, compared to the general population.

Someone with an ASD or VSD who wants to take up scuba diving should be discouraged from doing so. The diver with a known ASD or VSD should know what the implications are on their chances of developing decompression illness make an educated decision whether to continue diving or not. Individuals with a VSD, where the shunt is small and runs uniformly from left to right, as determined by an echocardiogram, may be able to dive if it is determined to be safe by a physician knowledgeable in diving medicine.
Posted in

No Comments


Categories

 2018 (60)
 2016 (119)
After anaesthesia Air Quality Altitude sickness Annual renewal Apnea Arthroscopic surgery BCD Badages Bag valve mask Bandaids Barbell back squat Bench press Bouyancy compensators Boyle's Law Boyle\'s Law Boyle\\\'s Law Boyle\\\\\\\'s Law Boyle\\\\\\\\\\\\\\\'s Law Brain Breast Cancer Breath hold Breath-hold Bruising Buoyancy Burnshield CGASA CO2 Camera settings Cancer Remission Cancer treatments Cancer Cape Town Dive Festival Carbon dioxide Charles' Law Charles\' Law Charles\\\' Law Charles\\\\\\\' Law Charles\\\\\\\\\\\\\\\' Law Chemotherapy Coastalexcursion Cold Water Cold care Cold Conservation Contaminants Corals Cutaneous decompression DAN Profile DAN Researchers DAN medics DAN report DCI DCS Decompressions sickness DCS DReams Dalton's Law Dalton\'s Law Dalton\\\'s Law Dalton\\\\\\\'s Law Dalton\\\\\\\\\\\\\\\'s Law Decompression Illness Decompression Sickness Decompression illsnes Diseases Dive Instruction Dive Instructor Dive accidents Dive computers Dive health Dive medicines Dive medicine Dive safety Dive staff Diveleaders Divers Alert Diving Kids Diving career Diving emergencies Diving injuries Diving suspended Diving Domestic Dr Rob Schneider EAP Ear pressure Ears injuries Emergency plans Environmental impact Equipment care Exercise Eye injuries FAQ Fatigue First Aid Equipment First Aid kits Fish Fitness Francois Burman Free diving Freediver Gas laws Gastric bypass Gordon Hiles HELP Haemorhoid treatment Health practitioner Heart High temperatures Hot Hydrostatic pressure Hypothermia Indian Ocean Inert gas Infections Instinct Instructors International travel International Irritation Kids scubadiver Labour laws Legislation Leukemis Liability Risks Life expectancy Lifestyle Low blood pressure Lung injuries MOD Maintenance Mammalian effect Maximum operating depth Medical Q Medical questionaire Medical statement Middle ear pressure Military front press More pressure Mycobacterium marinum Nitrox Non-rebreather Mask Nosebleeds O2 providers O2 servicing OOxygen maintenance Ocean pollution Orbital implants Oronasal mask Oxygen Cylinder Oxygen Units Oxygen deicit Oxygen ears Oxygen equipment Oxygen masks Oxygen supply Oxygen therapy Part 3 Plastic Pneumothorax Pool Diving Pulmanologist Pulmonary Bleb Radio communications Rashes Report incidents Rescue training Resume diving SABS 019 Safety Save our seas Science Scuba Injury Scuba children Scuba dive Scuba health Scubalearners Skin Bends Skin outbreak Skin rash Snorkeling Sodwana Bay Splits Squeezes Supplemental oxygen Surgeries Surgery The Bends The truth Thermal Notions Tides Travel tips Travel Tweezers Unconsciousness Underwater photographer Underwater pho Vaccines Vagus nerve Valsalva manoeuvers Vasvagal Syncope White balance Winter Wound dressings Wreck dive Youth diver abrasion air-cushioned alert diver altitude antibiotics antiseptics bandages bent-over barbell rows 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 dive diving attraction doctors domestic travel dri-suits dry mucous membranes dry suits dry ear spaces electroytes emergency action plans emergency assessment equalizing exposure injuries flexible tubing health hospital humidity immersion pulmonary edema (IPE join DAN longevity lower stress marine pathogens medical procedures medical risk assesment minor illness mucous membranes nasal steroids nasal newdivers nitrogen bubbles off-gassed operating theatre outgas pain plasters post dive preserve rebreather mask rebreathers risk areas saturation scissors scuba equipment scuba single use sinus infections stings strength tecnical diver thermal protection training trimix unified standards warmers water quality