heterotaxy d *and* l transposition?

[rjthkids]

My three month old daughter has multiple congenital anomalies, including heterotaxy. She spent the 1st 10 weeks of her life in the hospital, and is currently home.

One of my confusions lies with the hospital's back and forth use of d-transposition and "corrected" transposition  and I am trying to figure out how they correlate with each other.

From her last clinic note, this is an excerpt "...significant for heterotaxy syndrome (A, D, D), complete AV canal, physiologically corrected transposition of the great artieres with severe pulmonary stenosis, additional large secundum ASD, interrupted left IVC with azygous return to the left SVC, bilateral SVCs without bridging veins, hepatic veins to the left-sided atrium, pulmonary veins to the right-sided atrium, large left coronary artery from left facing aortic sinus,  right sided aortic arch with mirror image branching."

From her cardiac MRI it says in part "Abdominal situs ambigious with left sided liver  and right sided stomach. There were bilateral left-sided hyperarterial bronchi. There was no coronary sinus idenfitied. There was mesocardia. There was A, D, D type C complete AV canal defect. There are two well spaced papillary muscles in left ventricle, with common A-V valve regurgitation. There was mitral to pulmonary valve continuity and a complete sub-aortic conus. Severe valvar and subvalvar pulmonary stenosis with systolic flow acceleration into main and branch pulmonary arteries. Coronary artery origins were not seen."

What does A, D, D mean? I understand how her venous return is incorrect, but how does this all work together? I'm getting confused with all the "left on the right side, right on the left side", and I'm just trying to figure out how to succinctly summarize all of this in my head.

Thank you for your time

[rjthkids]

I understand if you don't have time to respond again, but I just really want to make sure I am understanding you correctly:

From what I hear you saying, her ventricles are on the correct side of the heart (right ventricle on the right and left ventricle on the left).

The D-position of the great arteries means that the position of them is incorrect--- because the aorta is supposed to be to the left of the pulmonary artery, not the right? So the aorta is in the right ventricle and the pulmonary artery is in the left?

And then they're throwing around "physiologically" corrected because her oxygenated blood from the pulmonary veins returns to the right "sided" atrium which (if there was no CAVC ) would then push blood to the right ventricle and to the aorta and the de-oxygenated blood from the hepatic veins is going to the left "sided" atrium/left ventricle and to the pulmonary artery? But it's different from true cc-tga because in cc-tga it's the ventricles that are transposed, not the arteries? (This is, of course, ignoring the additional blood flow confusion that the AV canal defect and common A-V valve and pulmonary stenosis add to everything).

Or, am I just completely making this all up and understanding your explanation all wrong?

I know it's my responsibility to ask her cardiologist these questions and I intend to....I'm just first trying to get an idea of what I'm misunderstanding, so I know what to ask. I think I'm in the phase of "you don't know what you don't know" and I'm trying to at least know enough to grasp what I am incorrectly understanding, KWIM? We're discussing the surgical options for her heart, such as a modified double switch, or a simpler option that would correct the AV canal defect and leave her RV as her systemic ventricle and I can't ask intelligent questions without starting with a good understanding of her anatomy.

Thank you very much for your time and your patience.

[Jeffrey R Boris, M.D.]

Dear Rjthkids,

It can be a very confusing nomenclature that we use.  And, it doesn't help that your daughter has heterotaxy, which means that the anatomy of the heart are as follows:  the atrial anatomy are ambiguous (i.e. not clearly appearing to be a right atrium and a left atrium); the ventricles are "D-looped", which means that the right ventricle is on the right, and the great arteries are in a D-position (D for dextro, or right), in which the aorta is rightward of the pulmonary artery.  However, this is not the same as "congenitally corrected" transposition, in which the "blue", or desaturated, blood gets sent to the pulmonary artery and the "pink", or oxygenated, blood gets sent to the aorta.  

In the end, it's a little more difficult to use that actual terminology for your daughter, though, because she has an atrioventricular canal, which leads to lots of mixing.  And, she has pulmonary stenosis, which leads to decreased blood going to the lungs.  So, the blood flow is more complex...