A Miraculous Muscle

I hate to admit this but before Maddie, I thought that the only heart defect a baby could be born with was a hole. Little did I know!!! There are 35 known heart defects. The combination of defects are infinite and many variations are a mix and match of several different lesions. Our daughter falls into this category and is dubbed "complex heart disease" on her chart since she has a few heart defects...it's difficult to understand if one caused another but after reading the book Walk on Water by Michael Ruhlman,
it's a wonder that so many babies are born with functional hearts with all that can go wrong during its development. (Note to other heart mom's: some parts of this book are TOUGH to read. It's taken me a year to get through most of it. I have to read it in bits and pieces or I become too overwhelmed!) Here's a bit from the book that I would like to share about the heart's first stages of development in utero...

From the moment its first cells twinkle into being, cells generated by the embryo's hunger, the heart is a feat of evolutionary genius. Just a couple of weeks past fertilization, these cells will have already formed a tube that pushes blood through the cell cluster. At about a month, this tube performs a critical maneuver: it pretzels, it loops and twists. "That's when it really gets interesting for me, " says surgical fellow Frank Moga. "That's when it starts to show its real complexity, when it makes that turn. It really achieves its three-dimensional beauty." It's also where things can begin to go wrong.

In addition to looping, the nascent heart must also now start to separate within itself into a right side and a left side, and each of those sides must have its distinct incoming and outgoing channels. Sometimes, these outgoing channels-an aorta-pulmonary helix-don't twist all the way, so that the aorta and pulmonary artery emerge from the wrong ventricles (transposition). And sometimes as the single muscular ventricle and the single thin-walled atrium squeeze off to form two of each, the inner wall doesn't quite grow together, leaving a hole between them (septal defect).

At the same time, two wispy valves-drifts of feathery-looking tissue, fine as butterfly's wing- should be forming between the atria and ventricles, as should two other, stiffer, three-flapped valves within the pulmonary artery and aorta. Any of these complex structures within the fetal heart can get stuck or not form at all. And all the while this organ must continue to squeeze nutrients through itself and therefore through the fetus. After four weeks, it's network of arteries has developed all around to feed it: the coronary arteries, which sometimes grow in odd places and occasionally come out of the wrong vessel altogether. As the arteries are developing, the other critical network is likewise taking shape: complex series of specialized muscle cells-cells that transmit electrical impulses-gather in the right atrium, then channel through muscle to another node in the ventricular part of the heart and disperse from there. These cells signal an atrial contraction, forcing blood down into the ventricles; then an electrical charge signals the ventricle to initiate its own contraction, propelling the blood up and out.

That's the heart; it's complete. The little creature growing around it is not even a fetus yet (at 8 weeks old, it's still called an embryo), and this ingenious pump-four chambers, four valves, arteries, veins, and a conduction system-is the size of the head of a pin.

Wow, right!?! Now it makes a little more sense when I read facts like...

• 1 in 100 babies is born with a CHD in the U.S.


• CHD's are the #1 birth defect and #1 cause for birth defect related deaths.


• This year almost 40,000 babies will be born with a CHD and 4,000 of them will not live to see their first birthdays.

Please help spread Congenital Heart Defect awareness...share these facts with those around you and be thankful for that miracle beating inside your chest.