Most common heart-related
conditions
- provided by America's leading
cardiologists
Imaging
Achievements made by scientists in medicine are
often most obvious in treatments and cures. But
imaging and the tests performed to screen for and
prevent disease are equally important. As cardiac
imaging grows more detailed it becomes even more
helpful in providing physicians the information
needed to assess your condition. Staying aware of
the latest developments will help you understand
that techniques available to help keep your heart
healthy.
What are the Various Diagnostic Imaging Tests?
Cardiovascular medicine has a variety of
diagnostic imaging tests used by doctors to help
identify and diagnose abnormalities in your heart.
Participants:
Richard P. Lewis, MD, MACC
Professor of Internal Medicine, Ohio State University,
Columbus, Ohio
Jacqueline A. Noonan, MD, FACC
Pediatric cardiologist, University of Kentucky College
of Medicine, Lexington, Kentucky
Webcast Transcript:
ANNOUNCER: For anyone with questions about the health
of their heart, there are a variety of diagnostic
tests available to physicians that can help provide
some answers.
RICHARD P. LEWIS, MD: Cardiovascular medicine has
more imaging tests than anybody else, by a long
ways. Actually, the first diagnostic imaging test
was a chest x-ray invented around the turn of the
20th century, so it's over 100 years old. It's still
helpful.
JACQUELINE NOONAN, MD: You know, in the olden days,
people used to use their stethoscope. And with the
stethoscope, if you had trained well, you could
diagnose rheumatic heart disease, what kind of valve
was involved, by listening. And this could be helped
by looking at an electrocardiogram, which would
tell you which side of the heart was thicker than
normal, whether the atrium was enlarged and use
certainly the chest x-ray.
Then cardiac catheterization came into vogue where
one could put a catheter into the heart and measure
pressures, put dye in and show defects, show whether
there was rheumatic heart disease, congenital heart
disease or whether the heart, which is not functioning
well. You could look at the coronary arteries with
coronary angiography.
RICHARD P. LEWIS, MD: The rest of the cardiac testing
has mostly been developed in the last 50 years,
and they fall into two basic categories: invasive
and non-invasive. And invasive means puncturing
the surface of the body. Non-invasive means not
having to do that.
The non-invasive tests consist of electrocardiogram
and chest x-ray; echocardiography, which is a widely
used test today; nuclear studies, where you inject
a radioisotope into the blood, and then look at
where it goes in the heart to see if there's areas
that aren't getting enough blood, that's a perfusion
scan. Or you can actually watch the heart contract
with the isotope that's inside the heart's blood
pool and watch the blood pool pass through the heart,
and you can define how well the heart's working.
That's a widely used test.
The echo is an extremely versatile test, because
it'll show you all of the heart valves and how they
work, the heart muscle, what kind of condition it's
in, whether there's fluid in the sac around the
heart, and a lot of other things that you could
do. And echo's an easy test to do, and you can do
it on really sick people in the intensive care unit,
emergency rooms.
Now, the invasive studies, diagnostic studies,
are mostly cardiac catheterization, which involves
putting a catheter in blood vessels, usually the
leg blood vessels, and advancing them into the heart.
And there we measure pressures inside the heart,
which is critical when you have abnormal heart valves,
and we can also inject contrast material, that you
can take an x-ray movie and see the outline of the
heart chambers and see how well the heart's working,
or you can see, most importantly, the heart arteries
and see how they're doing.
JACQUELINE NOONAN, MD: There are CAT scans, and
now there are improvements in the CAT scans, and
then there's the magnetic resonant imaging, MRIs.
So there are many different diagnostic tests that
can be used. There are also tests that can be used
to look for how good the oxygen in your heart is,
which reflects the coronary blood flow. Nuclear
scans, where one can do nuclear scans, both when
you're resting and when you're exercising, will
help us to understand whether your coronary arteries
are supplying the heart sufficient blood. So there
are many, many different kinds of diagnostic tests
available today.
What is Ejection Fraction and Why is it Important?
How does the amount of blood you heart pump affect your health? Get
the facts about this key function of the heart.
Participants:
Eric L. Michelson, MD, FACC
Senior Director, Clinical Development, AstraZeneca
Jacqueline A. Noonan, MD, FACC
Pediatric cardiologist, University of Kentucky College
of Medicine, Lexington, Kentucky
Nanette K. Wenger, MD, M.A.C.P., F.A.C.C., F.A.H.A.
Professor of Medicine, Division of Cardiology, Emory
University School of Medicine, Atlanta, Georgia
Webcast Transcript:
ANNOUNCER: In understanding how the heart works,
it important to know the meaning of the term "ejection
fraction."
ERIC MICHELSON, MD: The heart is a very effective
pump, and under normal conditions every time the
heart fills with blood, the pumping chambers, the
major chambers, the ventricles, eject that blood
into the major blood vessels. Ejection fraction
is a measure of the pumping function of the heart.
At rest, a normal person may have an ejection fraction
of approximately 55 percent. That means when the
pump is full and contracts, 55 percent of the blood
that was in the heart before it began to contract
is now ejected.
JACQUELINE NOONAN, MD: When you're not able to
maintain that normal level, it's usually because
your heart is not functioning well as a pump. Because,
remember, the heart is a pump. It's a muscle that
pumps blood and, when your ejection fraction is
low, it means the pump isn't working as well as
it should.
NANETTE KASS-WENGER, MD: The lower the ejection
fraction, the worse the pumping function of your
heart, and ejection fractions lower than 30 or 35
percent have a number of adverse consequences on
your health.
The information
published on this page has been provided by the
Heart Authority
in collaboration with Cardiosource – American College of Cardiology
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