Total anomalous pulmonary venous return is a condition where the veins returning blood to the heart from the lungs do not empty correctly into the arterial circulation. Children born with the condition do not usually survive or do well at all unless they also have an open atrial septal defect or patent foramen ovale. This is because the oxygenated blood has to be able to get into the arterial circulation in order to perfuse the body. They are born with the pulmonary veins draining into the right atrium instead of the usual left auricle.

At the time of surgery, the atrial septal defect or PFO is closed as the last part of the operation, ensuring that there will be no back flow into the arterial circulation. Now, if this closure fails – then we have a problem similar to the one that faces about 25% of divers who have a PFO – right to left flow of venous bubbles across into the arterial circulation with signs and symptoms of decompression illness.

Diving Concerns

Caveats that need to be taken into consideration is that rarely some of these patients later in life will develop arrhythmias from the extensive surgery performed in the wall between the left and right atria damaging the electrical pathways. This can require a pacemaker in some individuals. Also, early after the operation there is a complication of fibrosis or stenosis of the anastomosis between the vessels and the left atrium. This is not a long term complication, however, and would usually not be a factor in a person diving or not.

So- the three things that you need to have checked are:

—echocardiogram to rule out residual or recurrent atrial septal defect;
—EKG to rule out abnormal electrical patterns of her heart rhythm.
— Cardiac catheterization to rule out the possibility of stenosis in the event of shortness of breath and heart failure.

If these studies are normal, there would be no reason for the person not to be ‘fit to dive’.

Advising the Diver

—Potential for injury from future diving
Without evidence of injury to the conduction system at the time of surgery, there is little risk. Pacemaker management of the conduction problem can allow for diving in some situations. In case of the rare possibility of stenosis of the anastomosis occurring in adulthood, reoperation or dilation with the placement of stents has been reported. In this event, the diver would need evaluation as to ability to perform on the treadmill to 13 METs.

—Modifiers

–Degree of disability
–Findings on studies and degree of benefit from treatment as determined by studies.
–Need to dive; recreational, work related.

Dive or not dive
It would seem that if a person has become old enough to scuba dive and is without symptoms of cardiorespiratory failure or pulmonary hypertension – then diving should be considered after conduction deficits, shunts and pulmonary hypertension have been ruled out. Consultation with all physicians involved in the care of the patient performed.