Tuesday, January 19, 2010

What is L-TGA/C-CTGA?

(edited to add further explanation and diagram)

The heart is pretty complex! And although I try and explain Nate's heart in pretty basic terminology, it still can be pretty confusing. Here are a couple of pictures that might help make it more clear!

Corrected Transposition with VSD

Here's a detailed 'C-CTGA' heart:

correct tga

Congenitally corrected transposition of the great arteries (CCTGA) is a pretty rare heart defect in which the heart’s lower half is reversed. Of all babies born with a heart condition, approx. 0.5% - 1% have CCTGA. It is also called L-TGA. It is different from and much less common than “regular” transposition of the great arteries (TGA or D-TGA).

To understand CCTGA, it helps to first understand how a normal heart works. We're going back to Grade 9 Bio here! A normal heart is divided into two sides. The right side pumps blood from the body into the lungs. The left side pumps the blood from the lungs out to the body. Each side has an atrium and a ventricle.The atrium acts like a “waiting room” for the blood. The ventricle does the hard work of pushing the blood out to the lungs or body. At the entrance and exit from each ventricle is a valve, which acts like a door. These valves allow the ventricle to fill with blood from one side, and then push it out the other. Each ventricle and valve is designed to do its specific job. The right ventricle is designed to give the blood a gentle push to send it to the lungs. It is bigger than the left ventricle and does not have as much muscle. The left ventricle is designed to give the blood a strong push out to the body. It has less space inside because its thick walls take up more space. The valve between the left atrium and ventricle, the mitral valve, is the body’s strongest valve. It is designed to stay shut against the strong push of the blood out to the body.

In CCTGA, the two ventricles are reversed. The two valves "follow' the ventricles, so they are also reversed. The weaker, larger right ventricle grows on your heart’s left side. It now has to do the job of the stronger ventricle and pump the blood to your body. Your stronger, smaller left ventricle grows on your heart’s right side. It pumps blood to the lungs. Because it's the strong one, it's pumping with more pressure than is required to get to the lungs. And the body’s weakest valve—the tricuspid valve,serves as the mitral valve, which in most cases, Nate's included, is very leaky — and has to deal with the high pressure blood being pumped through.

edited to add:

Although the two heart valves and two arteries are transposed or exit from the 'wrong' ventricle, the blood flows to the correct place because the ventricles are also reversed. And that's why it's called corrected....2 wrongs kinda make a right!

Clear as mud? Don worry, there won't be a test!!


kristin said...

Thanks for the explanation Carole, I had it wrong, I thought it was his arteries and ventricles that were switched, didn't realize it was the valves and the ventricles. Do you know yet what they are planning to do in the surgery?

Hope they hold off another couple of weeks for you to be able to get your little vacation! We're headed to DC this weekend for Nath to get his hockey fix, oh and to have some family time :-)

Carole Hiebert said...

You are totally right Kristin! The ventricles and arteries are switched, and the valve follows along. I better reread my explanation to make sure that it's clear!
Still waiting on the date...
Sounds like you're in for some fun!!!! Have a blast this weekend!!

Nancy said...

Our son, Jameson, has the same heart condition plus WPW (Wolff Parkinson White Syndrome). He is now 17 and in the past two years he had two banding surgeries to prepare for the double switch surgery in the next year or so. You may contact us by e-mail at goxgo@rogers.com. Nancy and Colin Pearson, St. Marys, Ontario, Canada

jennifer said...

My daughter who is 12 has the same cardiac diagnosis. She had pulmonary banding at 6months and a double switch at 8months old. She is doing great!!