Terms & Definitions
These terms are new to us and will be to you. I know I get frustrated when I am reading something and someone uses terms or acronyms that I do not understand. Hopefully this will help sort everything out a little.
Artery – Vascular tubes that pump blood away from the heart
ASD – Atrial Septal Defect – a hole or opening between the left and right atria of the heart, causing oxygen poor and oxygen rich blood to mix. Critically necessary for Evan to live. If he wasn’t born with one, they would need to surgically make this hole (procedure called atrial septostomy) or ensure the patent foramen ovale doesn’t close after birth (by using prostaglandin drugs)
CHD – Congenital Heart Disease – a defect of the heart present at birth
Complex CHD – a CHD severe enough to require surgery in the first months of life
Ductus Arteriosis – PDA – Before birth, the ductus arteriosus allows blood to bypass the baby’s lungs by connecting the pulmonary arteries (which supply blood to the lungs) with the aorta (which supplies blood to the body). Soon after the infant is born and the lungs fill with air, this blood vessel is no longer needed. It will usually close within a couple of days. If the ductus arteriosus does not close, there will be abnormal blood circulation between the heart and lungs and it is called patent ductus arteriosis (PDA). PDA is common in babies with congenital heart problems, such as hypoplastic left heart syndrome, transposition of the great vessels, and pulmonary stenosis.
Fenestration – a small hole created between the left and right sides of the heart which allows for shunting. Performed at the time of the Fontan surgery and believed to relieve some side-effects of the surgery (such as fluid around the lungs or legs) with no longterm negative impact.
Foramen Ovale – PFO – a natural opening between the left and right atrium necessary and present in a fetus. It allows blood to bypass the non-working fetal lungs when the fetus receives oxygen from the placenta. After birth and upon gaining function of the lungs, this hole closes naturally in 24-48 hours. An ASD of sorts for the fetus, but one that is supposed to be there and one that will go away on its own. If this opening fails to close naturally, the hole is called patent foramen ovale (PFO) and is officially a ASD.
Glenn Procedure – When babies outgrow the first shunt, they often require a surgery that sets the stage for the Fontan procedure. Doctors usually perform the Glenn procedure when a child is about 6 months old. It connects one of the large veins that return blood to the heart (superior vena cava, the one coming from the upper body) to the pulmonary artery. This allows oxygen-poor blood to flow directly to the lungs. The procedure reduces the workload on the heart, decreasing the risk of damage to it.
HLHS – Hypoplastic Left Heart Syndrome – a CHD where anatomically parts of the heart are in the correct location, but the Left Ventricle is hypoplastic and cannot function as a pumping chamber. This is the syndrome that we were originally told that Evan had.
Hypoplastic – underdevelopment or incomplete development of a tissue or organ; smaller than normal
L-TGA – levo-Transposition of the Greater Arteries – a CHD in which the aorta and pulmonary artery are swapped. Additionally the morphological left and right ventricles are also switched. With l-TGA, oxygen-poor blood is pumped from the right atrium into the morphological left ventricle (which lies on the right side of the heart), then through the pulmonary artery to the lungs. The oxygen-rich blood then returns, via the pulmonary veins, to the left atrium from which it is pumped into the morphological right ventricle, then through the aorta. Evan has tricuspid atresia as well as L-TGA, so the flow from the left atrium to the right ventricle mentioned above does not happen in his heart.
Prostaglandin drugs – Often administered to CHD patients to help widen (dilate) the blood vessels and prevent the ductus arteriosus and foramen ovale from closing.
Shunt – BT shunt – Creating a bypass (shunt) from the main blood vessel leading out of the heart (aorta) to the pulmonary arteries allows for adequate blood flow to the lungs. Surgeons typically implant a shunt during the first four to eight weeks of life. However, babies usually outgrow this shunt and may need another surgery to replace it.
TA – Tricuspid Atresia – a CHD where the tricuspid valve is nonexistent. Without any other abnormality, it would be missing between the right atrium and ventricle. There’s currently no way to replace the defective tricuspid valve. Treatment for tricuspid atresia involves surgery to ensure adequate blood flow through the heart and into the lungs. Often, this requires more than one surgical procedure. This is one of the conditions that Evan has in addition to L-TGA.
Vein – Vascular tubes that pump blood to the heart
VSD – Ventricular septal defect – a hole or opening between the left and right ventricle, causing oxygen poor and rich blood to mix. Critically necessary for Evan to live. Without this opening, oxygen-rich blood could not travel through the aorta to the body (in a roundabout way: through the left atrium, ASD, right atrium, left ventricle, VSD, right ventricle, and finally the aorta)