The Diagnosis

It took me a while to really learn everything that was hooked up to him, and it has taken me nearly a year to really understand his diagnosis.  When I first talked to James on the phone, it sounded to me like he said that Enzo had an extra chamber on his heart.  What the doctors explained to me (several times) turned out to be a little different.  What I soon learned was this:  Enzo was born with a congenital heart defect called Total Anomalous Pulmonary Venous Return, more easily referred to as TAPVR.  It took me several days to memorize that one.  To understand his defect, I had to re-learn some basic heart anatomy.  A normal heart looks like this:

The heart is divided into 4 chambers.  The blood (blue) is pumped from the heart to the lungs through two pulmonary arteries to pick up oxygen.  The oxygenated blood (red) then returns to the left atrium of the heart through 4 pulmonary veins (2 from each lung.)  The heart then sends the oxygenated red blood from the left ventricle to the rest of the body, which uses up the oxygen and sends it back to the right atrium of the heart. 

In TAPVR, none of the 4 pulmonary veins connect to properly to the left atrium.  They instead somehow connect to the right atrium, where the oxygenated blood mixes with the un-oxygenated blood.  In order for a baby to survive at all with TAPVR, he must also have another defect called an Atrial Septal Defect(ASD), which is a hole in the heart in between the left and right atrium.   It is through this hole that the mixed blood is able to travel to the left side of the heart and then throughout the body.

There are several subtypes of TAPVR, categorized based on where the Pulmonary Veins end up connecting to the heart.  Enzo was born with Infracardiac TAPVR, where the pulmonary veins join together behind the heart and drain downward, through the diaphragm and into the liver, where they connect to the hepatic (liver) vein, which drains back into the right atrium.  Enzo’s veins were also obstructed, or narrowed, which further restricted the blood flow and caused blood to fluid to build up inside his lungs.  

Here is a picture of what Enzo’s heart looked like when he was born:

(You can click on the picture to see a detailed description of the pictures.  Thank you Nanette at heartbabyhome.com for making this picture for me!)

So how rare is this?  About 1 out of every 100 babies born are born with some kind of congenital heart defect.  About 2% of these are born with TAPVR .  And 13% of all TAPVR cases are the Infracardiac subtype.  If I've done my math right (which is questionable), somewhere around 1 out of every 50,000 babies are born with Enzo's specific heart defect.