Now we think of cardiomyopathy as myocarditis could be one type of cardiomyopathy,
but in pediatrics we have a lot of other causes of problems with the heart
that are unique to children.
So, in children, and it's not so important that you remember
all the genetic causes individually,
but remember there are a lot of genetic causes of cardiomyopathy in children.
Examples are: metabolic storage diseases such as Pompe's Disease,
conduction defects, mitochondrial disorders, ion channel disorders,
muscular dystrophies -- all of these genetic problems can cause a cardiomyopathy.
And they'll be different depending on the cause.
Pompe's disease for example can present very early in childhood
and have a cataclysmic march towards death in the first year of life.
Whereas muscular dystrophies, the cardiac disease doesn't present till much later
though it definitely causes problems and may only present in the adolescent years.
There are also acquired causes that are unique to children for cardiomyopathy.
Examples are, as we discussed previously acquired myocarditis.
There are also some very unusual ones.
One example is Takotsubo myocarditis.
Takotsubo cardiomyopathy is more common in older, postmenopausal women,
and it results from stress. It's referred to as literally “dying of a broken heart,”
as in very stressed women who develop an acquired cardiomyopathy.
In infants especially with tachycardia, we may see cardiomyopathy.
Unlike adults with tachycardia, for example in the case of SVT,
infants can be asymptomatic with heart rates in the 220-240 range for a long period of time
and may eventually develop a cardiomyopathy if the parent or the doctor doesn't notice the tachycardia.
Likewise, a common problem in infants is infants of the diabetic mother.
These infants have macrosomia and they may have too generous of a myocardium
resulting in a cardiomyopathy at birth.
So, how do these patients present with cardiomyopathy?
It really is different depending on the age.
But one consistent finding is decreased energy and exercise intolerance
that heart just can't keep up.
Remember in infants, a workout is just eating.
The biggest workout for a newborn baby is getting their mouth
around that nipple and having a meal.
And so babies with bad cardiomyopathy may present with sweating with feeds
or just not being able to tolerate feeds, only getting the first half in
and then becoming exhausted.
If they're older when they get it, it may be they can't finish their soccer game.
It really depends on the age.
Patients will eventually often develop congestive heart failure.
Remember congestive heart failure, they can have JVD,
they can have a large liver, they can become again having decreased energy and exercise intolerance
but part of that now may be from pulmonary congestion.
In severe cases they may present with unstable V-tach or V-fib.
These patients can go suddenly into a very severe rhythm
and require a resuscitation.
Or in the worst case scenario, patients may just suddenly die from a cardiomyopathy.
How do we test for it?
Typically these patients are in respiratory distress.
We'll get a chest x-ray and we'll see pulmonary vascular congestion
as well as a large heart.
EKG findings can be variable.
You can generally see alterations in the QRS complexes.
You can have a migration of the direction of that QRS.
We may get an echo where we can see the myocardium not working correctly.
If we want to make the diagnosis and truly understand what's going on,
remember in children some of these causes are metabolic or genetic.
We will often end up with getting a myocardial biopsy
Usually through femoral catheterization up into the heart,
get a little piece of that, send that to the lab,
and the microscopy can help us with that diagnosis.
Also, genetic testing is often indicated.
And now there are genetic panels we can send
which can help us understand which gene might be responsible for what's going on.
That can help not only therapy with the patient
but also future counseling for the parents.