00:00
In this lecture, we're going to focus on acquired conditions of the heart.
00:05
Specifically, we're going to look at endocarditis, myocarditis,
causes of cardiomyopathy, and also pericarditis.
00:15
Let's start with infective endocarditis.
00:20
Infective endocarditis is quite rare in children.
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It's more common in infants who've had catheters,
or in adolescents who were using IV drugs.
00:30
But we see it rarely, maybe 1 in 300,000 people.
00:33
But despite of it being rare, it is dangerous
and it does confer about an 11 percent mortality rate in children.
00:42
The incidence in the United States in children is increasing
likely through more children going through NICUs
and through increased use of IV drugs.
00:54
Let's look at the bacteria that are most likely to cause endocarditis
and specifically focus on how the bacteria
relate to the presentation of the patient.
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One of the most common causes of bacteria causing endocarditis in children
is Staphylococcus aureus - we'll call it "Staph aureus".
01:13
Staph aureus is a very aggressive ogranism.
01:16
It can cause acutely very ill children
and can also cause abscess formation within the context of the inside of the heart.
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Coagulase-negative Staph is more subacute - results in chronic fevers.
01:32
Alpha-hemolytic Strep can also cause endocarditis -
and again, that's more a subacute condition with chronic fevers.
01:40
Gram-negative rods can rarely cause endocarditis.
01:44
Those patients will have subacute illness and chronic fevers,
but also may be more likely to develop embolic disease,
clots forming as the blood flicks out of the heart.
01:55
Fungal endocarditis is very severe
and these infants will present usually with very acute illness
and they have a very high mortality rate.
02:06
When you're seeing a patient with endocarditis,
there would be a few key points to their history.
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Often, they will have diffused myalgias.
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They may have fatigue.
02:20
They'll have arthralgias or sore joints.
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But key is they'll have fever,
and this is in you differential for a child with fever of unknown origin.
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On exam, there are many key findings
that are pretty high-yield or likely to show up on an exam.
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They may have a toxic appearance.
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They may have a new onset heart murmur, though they don't have to.
02:45
You'll notice neurologic symptoms if they have a left-sided endocarditis,
which is common among endocarditis,
and those bacteria could be flicking off systematically
and getting into the brain resulting in
abnormal mentation, stroke, brain abscesses, meningitis.
03:07
You may see Osler nodes on their exam -
and we'll talk about what those are in a second -
you may see Janeway lesions,
and you may see splinter hemorrhages.
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And last, you may see Roth spots.
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I'm going to go through these four physical exam findings carefully.
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First, Osler nodes. Osler nodes are found usually on the extremities.
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They are small, tender, raised nodules.
03:35
They're usually on the pads of the fingers and toes.
These are rare.
03:41
I have personally never seen an Osler node,
but they love asking about them on test questions.
03:47
Janeway lesions are also rare. These are flat, red lesions.
03:53
They're found on the palms and soles.
03:55
In this patient on this slide, you can see them right there on their fingers.
03:59
These are painless unlike the Osler nodes, which are a little bit tender.
04:04
Also, these patients may have splinter hemorrhages on their nails.
04:09
Last is Roth spots. These are on the ophthalmologic exam.
04:13
On fundoscopy, you can see these little lesions in there
that are in the retina.
04:19
These are retinal hemorrhages as a result of clots
landing in the retinal artery in that capillary bed.
04:27
You'll notice, especially with the one with the white arrow,
that there's a pale center, and that's what's key in a Roth spot.
04:36
If you see something in a patient
regarding their history or their physical exam and you suspect endocarditis,
what's key is a large volume blood culture.
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This is a blood culture of between 5 and 15 milliliters of blood.
04:51
It's a huge amount of blood obtained for blood culture.
04:55
Small volume blood cultures are suboptimal.
04:59
These large volume blood cultures
will be positive in more than 90 percent of cases.
05:04
Often, if we suspect it, we may obtain multiple large volume blood cultures
on subsequent days to make the diagnosis.
05:13
A cardiac echo is indicated to look for a lesion
that may be growing on one of those valves.
05:20
But remember, false positives and false negatives on endocarditis
on the echo are common.
05:27
Frequently, the echo will be normal in a patient with endocarditis.
05:34
How do we treat endocarditis?
Antibiotics are key.
05:38
Generally, you're going to treat the organism that grows on the culture.
05:42
If you strongly suspect endocarditis
but don't have the identity of the organism,
remember that everyday this child has bacteria growing on his or her valve
is a day of valvular destruction,
which can result in great pathology down the road.
06:00
So initial therapy should be broad coverage and aggressive.
06:06
We'll often give this children vancomycin and ceftriaxone,
and maybe add in amphotericin if we suspect a fungal agent,
especially in the critically ill children.
06:18
The therapy is going to be prolonged
and will usually require a PICC line placement
and a very prolonged six to eight weeks of IV antibiotics.
06:28
In patients who have a history of endocarditis,
we may put them on prophylaxis.
06:35
If they have a history of endocarditis,
they'll be on antibiotics every day to prevent a reinfection.
06:40
They may also need prophylaxis of the prosthetic valves,
or if they are a heart transplant.