Atrial Fibrillation, or A-fib, is one of the problems many CHDers will face. In a normal heart, an electrical signal is generated by the Sinoatrial node (also known as the SA node and is located near the top of the Right Atrium) and flows outward, causing the Atria to contract. When the electrical impulse reaches the Atrioventricular node, (AV node) it triggers its own electrical impulse which causes the Ventricles to contract, creating the “lub-dub” heartbeat we are all familiar with.
But when extra electrical impulses are moving through the heart’s electrical system, the Atria won’t contract, but rather fibrillate, or quiver. And if the electrical pulse isn’t strong enough the AV node won’t activate the Ventricles. A-fib is usually asymptomatic and painless, (though you can feel your heart beating out of rhythm) but there is a very real chance that the blood pooling in the not-quite-beating upper chambers can clot and cause a stroke.They can also lead to Congestive Heart Failure. (CHF)
One of the usual techniques used to stop A-fib is ablation. Before an ablation, the heart is examined closely and “mapped” to determine where the extra electrical impulses are coming from. Then a catheter is inserted through a vein in the leg or the neck and is guided to the heart. The sources of the extra electrical impulses are then “zapped” (or frozen) to knock them out, and the heart beat should be restored to normal. It doesn’t always work.
But researchers have recently determined that the cells that produce the heart’s electrical charge – and can cause Atrial Fibrillation – also express the protein DCT. DCT only originates from a couple of sources in the body, and only one inside the heart – the electrical current cells. So if scientists can learn a way to identify DCT cells in the heart, they’ll have a way to determine where electrical pulses can orgininate – and deaden the ones causing A-fib.
But this technology is a long way from being reality, if it works at all. Right now, studies are being conducted on mouse hearts. Mouse hearts are similar to human hearts, close enough to be used in research. But when it comes to transferring the results from a mouse to a man, there is a lot of difference!