Understanding Double Inlet Left Ventricle (DILV)

Double Inlet Left Ventricle Example

One of the difficult things to do since receiving Brent's diagnosis is explaining his condition in a way that people can grasp and make sense of.  We even continue to learn more about the condition ourselves, and are by no means doctors or experts.  Because there are at least 18 types of congenital heart defects, the mistake people often make is relating it to one they have heard about.  One of my prior posts contains a YouTube video explaining Double Inlet Left Ventricle (DILV) more from a medical perspective.  Once you have had a cardiologist walk you through your baby's defect, the video is very easy to follow.  Since our family and friends have not had that, this post is my attempt to try to explain the condition hopefully in a way that is easier for you to understand.

DILV is very, very rare.  It is one of the types of "single ventricle defects".  These are rare disorders affecting one lower chamber of the heart.  Overall, congenital heart defects occur in about 9 of ever 1,000 births.  DILV on the other hand occurs in 5-10 of every 100,000 live births.  So, if I'm doing my math right, using recent birth rates of about 3.9 million per year, that means around 39,000 babies will be born each year with some type of congenital heart defect, while only 200-400 of those babies will be born with DILV.

DILV currently cannot be "fixed".  When I explain to people that Brent will undergo multiple open heart surgeries along with, likely other heart surgeries, I often get the reply "Well, at least it's something they can fix".  I understand the sentiment the person is trying to convey, but DILV currently cannot be "fixed" - at least with today's medical technology.  The surgeries Brent will undergo are designed to offer what they call "palliative care".  The surgeries will help treat and relieve some of the symptoms of his condition, but they will not "fix" the underlying defect.

With these things in mind, I will try to explain his condition as best I can and to the degree I understand it currently.  The picture below is the best I have found that diagrams a normal heart versus a heart with DILV - the heart on the left is your heart if you have no defects.  The heart on the right is Brent's heart.  I will bullet point a few of the differences that are important to distinguish:

• First, notice that a normal heart has a "right" and "left" ventricle.  The right ventricle pumps your blue blood.  Brent did not develop this ventricle - well at least it is very small and what they call "hypoplastic".  It is not capable of performing it's intended function.
• Second, notice that a normal heart has a division between the right and left ventricle.  This keeps blue and red blood from mixing together in the heart.  Brent does not have this division.  This is what is called a "ventricular septal defect".  Some people have this defect without having DILV and, but itself, it is common and something that doctors can fix.  Brent has it in conjunction with his DILV and his blue and red blood will mix together.
• Third, notice in a normal heart that the pulmonary artery laps over the aorta.  In the DILV heart, positions of the great vessels are reversed.  This is called "transposition of the great arteries", and again, it is a defect that can occur by itself, absent of DILV, but in Brent's case, he has it in conjunction with his DILV.
• Last, notice in a normal heart the left ventricle is on the right side if you are facing the image and the right ventricle on the left side (they are actually on the right and left side of the actual body).  In DILV hearts, the ventricles are switched - Brent's left ventricle is actually on the right side of his body. 

This is all complicated and a little technical, but it's necessary to understand the following main points:

• Barring a complete miracle, Brent will only ever have 1 ventricle in his heart.  I've read people with this condition often describe it as having "half a heart".  Basically, this is a simplistic and easy way of helping people understand it.  He does not have 1 of the ventricles needed to pump the blue blood throughout his veins.  The surgeries he will have are designed to address that.
• The series of surgeries Brent will have will allow his blue blood to completely bypass his heart and drain/flow to his lungs directly.  Until then, his blue and red blood will mix together in his heart.  Some of the complications his heart condition could create for him are: blue skin, failure to gain weight normally, trouble breathing, swollen legs or abdomen, pale skin, poor feeding, sweating, fast heartbeat, heart murmur, fluid buildup around the lungs, heart failure.
• The surgeries invented to treat this came about in the late 70s, early 80s.  As a result, a lot is still unknown/uncertain regarding things like life expectancy, survival rates, complications, etc.  See my wife's recent post here.

I hope this helps our family and friends understand the condition a little better - and anyone stumbling across the blog for that matter.  We feel very good about the care Brent will be receiving, and have some good news to share on that front in my next post.  Until then, we appreciate all the prayers and well wishes that are being sent our way!  Keep them coming :)

David