00:00
muscle in arrhythmogenic cardiomyopathy.
Let me just give you some final hints about
advanced therapy for these patients. Patients
with cardiomyopathy and severe heart failure,
let’s say a typical patient with dilated
cardiomyopathy, may get to the point where
drugs no longer work and where we’re preparing
to do a heart transplant. Often it takes a
while before there’s a heart available and
some of these patients are so sick, sick unto
almost dying, that we actually implant a small
pump to help the ventricle work for some months
until a heart becomes available for a heart
transplant. There’s now, as you probably
know, even artificial hearts, totally artificial
hearts, one of which was pioneered at my institution,
the University of Arizona in the United States,
a so-called “CardioWest”, total implantable
artificial heart. They work quite well and
I’ve seen a number of patients walking around
with a knapsack on their back that contains
the power source that actually goes through
the skin and you can always tell these patients
when they’re walking in the hall because
they walk by you and they’re going, “Thucka–thucka–thucka–thucka–thucka–thucka.”
So you know you’re seeing, actually, the
artificial heart in function and people do
very well. The problem is often blood clots
because of all the mechanical machinery that
the blood is in contact with. They have to
be very aggressively anticoagulated and we
usually think of this as a temporary step
towards heart transplantation, when the patient
is so sick that we don’t think that they’ll
stay alive until we can find them a heart.
There is some talk, if we can get these artificial
hearts to be good enough, that we would not
transplant these patients, we would leave
them with the artificial heart. That’s still
very experimental, but it would be hopeful
because only about 10% of the patients that
require a heart transplant actually get one.
01:52
Here, we see another device I mentioned before.
This is the implantable cardioverter–defibrillator.
01:58
It’s a kind of pacemaker that monitors the
condition of the electrical activity in the
heart and when it sees a malignant ventricular
arrhythmia, and we’re going to talk about
those in a subsequent lecture, it actually
shocks the heart and returns it to normal
rhythm. For example, patients who’ve suffered
a cardiac arrest from either dilated cardiomyopathy
or patients who’ve suffered a cardiac arrest
from hypertrophic cardiomyopathy or people
who we feel are at high risk for developing
a cardiac arrest have one of these little
devices implanted. They’re quite expensive,
but their use is quite common in people with
the dilated forms of cardiomyopathy, much
less common in people with hypertrophic myopathy.
02:41
As I’ve told you, many are not really at
risk of dying suddenly. And finally, there’s
heart transplantation. Unfortunately, only
about 10% of individuals who need one get
one. So, there’s great hope that eventually,
a totally implantable heart will solve this
problem, that we could replace the heart,
just as we replace the kidneys with dialysis,
with a mechanical device and we wouldn’t
have to constantly be worried about patients
who aren’t going to get a heart just because
there aren’t enough.
03:10
In summary, then, that’s been a very quick
look at cardiomyopathies. They’re a very
interesting group of diseases, particularly
the genetic forms, and these are diseases
that are being intensively studied right now
to see if there isn’t some way to improve
the long-term outcome for some of the nastier
forms of this disease.