“Clinical Presentation of Congenital Heart Disease: Cyanosis” by Michael Freed, MD

“Clinical Presentation of Congenital Heart Disease: Cyanosis” by Michael Freed, MD


Clinical Presentation of Congenital Heart
Disease in the First Week of Life: Cyanosis, by Dr. Michael Freed. My name is Michael Freed, and I’m a Pediatric
Cardiologist at Boston Children’s Hospital and at Harvard Medical School. I want to spend a little time today talking
about congenital heart disease in the newborn period. Introduction. Children come in in the first week of life,
they present in one of four ways: with a heart murmur, with an arrhythmia, congestive heart
failure, or with cyanosis. Let’s deal with cyanosis. Cyanosis is actually more complicated than
the others. I would maintain that, on the basis of physical
exam, EKG and x-ray, we can sort out the main types of cyanotic congenital heart disease
before we get an echocardiogram, before we raise the flags. Approach to Diagnosis of Cyanotic Congenital
Heart Disease. Let’s start with different types of cyanotic
congenital heart disease that present in the first week of life. And these are the kids that are really blue. Kids with common mixing, like single ventricle
or truncus, as I said, usually come in in heart failure a little bit later. So these are the kids who have saturations
in the 40s, 50s, 60s, 70s, the really blue, blue ones. The first type is transposition of the great
arteries with an intact ventricular septum. And these kids have relatively normal parts. But instead of the pulmonary artery coming
off the right ventricle, the aorta comes off the right ventricle, and the pulmonary artery
comes off the left ventricle. So blood from the body goes right atrium,
right ventricle, out the aorta, back to the body. Blood from the lungs– left atrium, left ventricle,
out to the pulmonary artery. And these kids, to survive, need some kind
of mixing, usually at the ductile level and the atrial level. But these kids come in very sick in the first
few days of life. The second is total anomalous pulmonary venous
connection. These are kids who the pulmonary veins never
get back to the left atrium. So they do okay in utero, because there is
usually some connection from the common pulmonary vein behind the heart to the right superior
vena cava or left superior vena cava or umblical vitelline system. When they’re born, all of a sudden, they can’t
get blood out of the lungs. The blood backs up into the lungs. They get very high pulmonary venous pressure
and go into pulmonary edema. Ebstein’s, which is an abnormality of the
tricuspid valve. So they get severe tricuspid regurgitation,
elevating their right atrial pressure. And they shunt right to left at the atrial
level. Tricuspid atresia– so in tricuspid atresia,
the tricuspid valve never forms. The right ventricle is either very small or
nonexistent. Blood comes back to the body into the right
atrium, can’t get through here, goes across the foramen ovale into the left atrium, left
ventricle, out the aorta to the body. Some of it goes through the ductus arteriosis,
out to the lungs, where it gets oxygenated, and comes back again. So in utero, this is not a problem. And after birth, this isn’t a problem. But when the ductus arteriosis starts closing,
then the amount of blood going through here diminishes. The blood going to the lungs to get oxygen
is reduced. And gradually, the arterial saturation will
decrease. There will be more hypoxemia. Pulmonary atresia, intact ventricular septum. So these kids have no outlet to the right
ventricle. Usually, right ventricle doesn’t grow very
much. So these kids, blood comes back from the body,
right atrium, can’t get out this way, goes out this way, out this way. And again, these kids are dependent on their
ductus arteriosus for their blood flow. And when the ductus arteriosus closes, they
get into difficulty. Pulmonary stenosis– we talked about before. If you look at pulmonary stenosis, these kids
have severe right ventricle outflow tract obstruction. The right ventricle has to generate a higher
pressure to pump blood out. And if it starts having difficulty generating
that higher pressure, by Starling’s law, it increases preload. If you increase the preload in the ventricle,
the atrial pressure goes up. And in the newborn period, if the right atrial
pressure exceeds the left atrial pressure, you start shunting right-to-left and you end
up with cyanosis. Tetralogy of Fallot with pulmonary stenosis,
or Tetralogy of Fallot with pulmonary atresia. So with these kids with a ventricular septal
defect and pulmonary stenosis, blood coming back from the body, right atrium, right ventricle,
difficulty going out here. So some goes out to the body. Some goes through here to the lungs and back
again. With pulmonary atresia, nothing goes out this
way. And they’re dependent on the ductus arteriosus. So as mentioned before, they get into difficulty
when the ductus closes. Now, all of these children are blue for one
reason, with the exception of one group that’s blue for a different reason. All of these kids from here down are blue
because blood that should have gone out to the lungs somehow gets diverted into the systemic
circulation. So in Tetralogy, at the ventricular level,
tricuspid atresia, pulmonary atresia, pulmonary stenosis at the atrial level, total anomalous
pulmonary venous connection, either right-to-left shunting at the ductus. Or if the ductus closes, they right-to-left
at the atrial level, Ebstein’s at the atrial level. So if you were to look at a chest x-ray and
look at the pulmonary blood flow, all of these guys have diminished pulmonary blood flow. If you look at the hilar vessels, you see
very little hilar vessels and almost nothing out in the periphery. As opposed to transposition, who remember
have these two separate circulations, but have a normal amount of blood flow, or it
sometimes is actually increased– nobody knows what sets the cycle of how much it flows–
but if you were to get a chest x-ray and look at the pulmonary blood flow, if they have
normal pulmonary blood flow, they’ve got transposition of the great arteries. There’s nothing else in the newborn that gives
you cyanosis without respiratory distress and normal pulmonary blood flow. In fact, this is not new. This was information that Dr. Taussig published
in a paper in 1938. Using fluoroscopy, she could tell the kids
with transposition from everyone else because of their normal pulmonary blood flow. There are a couple of other patterns on the
chest x-ray that are pathognomonic. One of them is Ebstein’s disease. And they have a huge heart. And this is all right atrium. The in utero tricuspid regurgitation dilates
the right atrium. So the heart is just almost sometimes wall
to wall. I usually pick this up when I’m looking for
the pulmonary blood flow. And I’m looking for the lungs, and I can’t
find the lungs, because there’s this big white blob in the middle. A big white blob, oh big heart, Ebstein’s
disease. So blue with a huge heart, these are the–
you get a huge heart because of congestive heart failure or because of significant volume
overload. None of these other kids have significant
volume overload. So the hearts are normal. So cyanosis, huge heart, Ebstein’s disease. The other pattern that’s typical is total
veins. And these kids have pulmonary edema. Pulmonary edema in a newborn is just a white-out
of the lung. They get fluid in all their alveoli. So they just don’t– it just shows up white
on an x-ray film. There’s another disease in the newborn that
gives you a white-out of the lung. And that’s RDS. So how do we separate these kids from RDS? Well, I usually do it from across the room. If they’re this big, they have RDS. And if they’re this big, they have total veins. I think if you have a 25-week-old, 26-week-old
premature, the overwhelming odds are that he’s got RDS. If he’s 38 weeks, be careful about atypical
RDS in 38-weekers, because some of them will have total veins. In fact, it’s sometimes quite hard to tell
these apart. I mean, pathophysiologically, there are a
lot of similarities. Both of them have fluid in all the alveoli,
so they don’t oxygenate very well. And both of them have high pulmonary resistance,
so they shunt right-to-left at the atrial or great vessel level. So these are actually hard to tell apart. And we have a standing rule here that any
baby, any newborn, who’s going on HIFI respirator or ECMO has to get an echo to make sure they
don’t have total veins. And every couple of years, we find a baby
who the neonatologist thought probably had RDS who actually had total veins. The x-ray is telling you what’s going on in
that 1/30 of a second that you snap the picture. The EKG is telling you something different–
what the blood flow was in utero. Which was the ventricle that was doing most
of the work in utero? Which ventricle was the predominant ventricle? With tricuspid atresia, remember these are
the kids where the blood is shunting at the atrial level. Not very much blood goes into the right ventricle. The right ventricle is usually quite hypoplastic. In these kids, the left ventricle is doing
most of the work. In pulmonary atresia, intact ventricular septum–
again, these are the kids with a very small right ventricle– left ventricle is doing
the work in utero. In Tetralogy, both ventricles are working
in utero. And when you have both ventricles of equal
size on the electrocardiogram, you get right ventricular hypertrophy. Pulmonary stenosis. I could make a good case for either of these. And it turns out that, if you present in the
newborn period, you have LVH. So now, if you have a newborn who is blue
with diminished pulmonary blood flow, and he doesn’t have pulmonary edema or a big heart,
if he’s got left ventricular predominance, he’s got one of these things, he’s got a small
right ventricle. He’s got right ventricular predominance, he’s
got Tetralogy of Fallot. There’s something characteristic about the
QRS axis in tricuspid atresia. And that is, it’s superior, minus 30 to minus
90 degrees. So if we look at the heart sitting in the
chest, this is the left ventricle, this is superior, inferior, left, right. Normally, the heart depolarizes down in this
direction, so we get a QRS axis in the 70 or 80 range. Newborns, a little bit further, but it’s still
depolarizes down in this direction. These kids, the heart depolarizes up in this
direction. And we see this in one other disease in complete
AV canals. And remember the His-Purkinje system runs
along the tricuspid annulus and then escapes out into the myocardium. Well, in both these diseases, the tricuspid
valve is displaced. So somehow, the His-Purkinje system comes
more inferiorly, and they depolarize in a superior direction. These kids are plus 30 to plus 90, plus 30
to plus 90. So if you have this hypothetical child with
diminished pulmonary blood flow, left ventricular predominance, if he’s got a superior QRS axis,
he’s mostly likely got tricuspid atresia. If he’s got an inferior QRS axis, then he’s
got either pulmonary stenosis or pulmonary atresia. And kids with pulmonary stenosis will usually
have a systolic ejection murmur. [MURMUR SOUNDS] Kids with pulmonary atresia usually have no
murmur. If this hypothetical baby has diminished pulmonary
blood flow, doesn’t have pulmonary edema or a big heart, and has RVH, then he’s likely
to have Tetralogy of Fallot. And you can tell these apart– children with
Tetralogy of Fallot and pulmonary stenosis will have that systolic ejection murmur. [MURMUR SOUNDS] While kids with pulmonary atresia have no
murmur. Or sometimes you can hear continuous murmurs
from the collateral vessels. A pearl is, watch out for continuous murmurs
in the newborn period. It’s not a ductus arteriosus. Usually, the pulmonary pressure isn’t low
enough to give continuous murmurs in the first few days of life. If you have continuous murmur, worry about
pulmonary atresia. And that separates out all of these. Now, this type of pattern is not perfect. If it were perfect, you wouldn’t need pediatric
cardiologists or echocardiographers. But when it’s been studied in a large group
of people, it’s about 60% to 70% accurate. It falls down where you would expect it to
fall down. You can’t separate out single ventricles with
pulmonary stenosis from Tetralogy. You’re just not going to be able to tell the
size of the VSD from this kind of pattern. And you can miss malaligned AV canal with
pulmonary stenosis. So they look blue, they look like tricuspid
atresia, but it’s really just a malaligned canal. But this is a pretty good way of looking at
newborns before you get the echocardiographers involved. So this is a relatively straightforward way
of looking at newborns with heart disease. It’s a good overview on how congenital heart
disease presents in the first week of life. Thanks very much for listening. This concludes our video on Clinical Presentation
of Congenital Heart Disease in the First Week of Life: Cyanosis. Please continue with the next video in this
series, Clinical Presentation of Congenital Heart Disease in the First Week of Life: Congestive
Heart Failure. Thank you. Please help us improve the content by providing
us with some feedback.