Atrial septal defect decompression sickness


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Overview
Patients with patent foramen ovale and less frequently atrial septal defect are predisposed to decompression sickness. Decompression sickness or diver's disease occurs when body encounters depressurization such as in scuba diving, caisson working, flying in unpressurized aircraft, and extra-vehicular activity from spacecraft. The reduced pressure causes dissolved gases coming out of solution into bubbles inside the body on depressurization. Since bubbles can form in or migrate to any part of the body, Decompression sickness can produce many symptoms, and its effects may vary from joint pain and rashes to paralysis and death.

Decompression sickness
ASDs, and particularly PFOs, are a predisposing risk factor for decompression sickness in divers because a proportion of venous blood carrying inert gases, such as helium or nitrogen does not pass through the lungs. The only way to release the excess inert gases from the body is to pass the blood carrying the inert gases through the lungs to be exhaled. If some of the inert gas-laden blood passes through the PFO, it avoids the lungs and the inert gas is more likely to form large bubbles in the arterial blood stream causing decompression sickness. Since bubbles can form in or migrate to any part of the body, DCS can produce many symptoms, and its effects may vary from joint pain and rashes to paralysis and death.