Atrial septal defect with atrioventricular conduction defects (ASD-AV) is a developmental problem of the heart. During development, there is normally a hole in the wall of the heart allowing oxygenated blood from the right side of the heart to pass to the left side without going to the lungs first; this hole usually closes after birth. However, in ASD-AV, this hole fails to close. This can cause a major problem because it allows oxygen-rich blood to leak into the oxygen-poor blood chambers in the heart. The heart is then forced to work harder because the mixing of blood decreases the available oxygen for the rest of the body to use.
In this condition specifically, there are also problems with transmission of electricity through the heart, which interfere with the natural pacemaker of the heart. The conduction of electricity between the atria (upper chambers) and ventricles (lower chambers) of the heart does not occur as it should. Symptoms of ASD-AV can include swelling of the legs, feet, or abdomen, shortness of breath, fatigue, heart palpitations, stroke, and an audible heart murmur.
ASD-AV is a genetic condition caused by mutations (changes) in the NKX2-5 gene.We inherit our genes in pairs, one from each parent typically. ASD-AV is inherited in an autosomal dominant manner. Autosomal dominant means an individual only needs one copy of the changed gene or mutation that causes the condition. If one parent is a carrier for the mutated gene, children have a 50% chance of having the condition.
ASD-AV can be diagnosed by performing a physical exam, listening for a heart murmur, and using tests such as an echocardiograms, chest X-rays, and ECGs in order to get clear images of the heart. Treatment varies by individual cases, but may include surgery or cardiac catherization to close the hole in the heart wall and medications to reduce signs and symptoms.
Description Last Updated: Sep 03, 2018