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Heart Tests
Heart imaging tests
Heart imaging tests take pictures of your heart
or its arteries or blood vessels to help your
doctor see whether there are any problems.
Cardiac CT scan
A cardiac computed tomography (CT) scan, also
called a "CAT scan,” is a painless, non-invasive
imaging test that uses X-rays to take many
detailed pictures of your heart and its blood
vessels. Computers can combine these pictures to
create a three-dimensional (3D) model of your
whole heart.
This imaging test can help doctors find heart
diseases or problems with the heart or blood
vessels supplying blood to the heart or the rest
of the body. This test may also be used to check
the results of coronary
artery bypass grafting or to follow up on
abnormal findings from earlier chest
X-rays. You may go to a medical imaging
facility or a hospital for a cardiac CT scan.
The scan itself usually takes only about 15
minutes. However, it can take more than an hour
to prepare for the scan, including time to take
medicines such as beta blockers to slow your
heart rate or nitroglycerin to help dilate your
arteries. Before the test, a healthcare provider
will inject a contrast dye, often iodine-based,
into a vein in your arm. This contrast dye
highlights your blood vessels and creates
clearer pictures. You may feel some discomfort
from the needle or, after the contrast dye is
injected, you may feel a warm flush briefly
throughout your body or have a temporary
metallic taste in your mouth.
The CT scanner is a large, tunnel-like machine
that has a table. You will lie still on the
table, and the table will slide into the
scanner. Talk to your doctor if you are
uncomfortable in tight or closed spaces to see
if you need medicine to help you relax during
the test. During the scan, the technician will
monitor your heart rate with an
electrocardiogram (EKG). You will hear soft
buzzing, clicking, or whirring sounds when you
are inside the scanner and the scanner is taking
pictures. You will be able to hear from and talk
to the technician performing the test while you
are inside the scanner. The technician may ask
you to hold your breath for a few seconds during
the test.
Cardiac CT scans have some risks. In rare cases,
the contrast dye may cause damage to the
kidneys, particularly in people who have known
chronic kidney problems. Your doctor or the
imaging center may do a blood test to check your
kidney function before the exam. In rare
instances, some people may have an allergic
reaction to the contrast dye. If you have a
known allergy, you may still be able to receive
contrast if you receive medicine ahead of time.
There is a very slight risk of cancer,
particularly in people younger than 40 years old
who undergo multiple CT scans, because the test
uses radiation.
Talk to your doctor and the technicians
performing the test about whether you are or
could be pregnant or are breastfeeding.
Rarely, people with lung diseases or heart
failure may have breathing problems during
cardiac CT scans if they are given beta blockers
to slow their heart rates for this imaging test.
Used for:
Coronary calcium scan
A coronary calcium scan is a CT scan of your
heart that measures the amount of calcium in the
walls of your coronary arteries. Buildup of
calcium, or calcifications, are a sign of atherosclerosis or coronary
heart disease.
A coronary calcium scan may be done in a medical
imaging facility or hospital. The test does not
use contrast dye and will take about 10 to 15
minutes to complete. A coronary calcium scan
uses a special scanner such as an electron beam
CT or a multidetector CT (MDCT) machine. An MDCT
machine is a very fast CT scanner that makes
high-quality pictures of the beating heart. A
coronary calcium scan will determine a score
that reflects the amount of calcium found in
your coronary arteries, often referred to as an
Agatston score. A score of 0 is normal. In
general, the higher your score, the more likely
you are to have coronary heart disease. If your
score is high, your doctor may recommend more
tests.
A coronary calcium scan has few risks. There is
a very slight risk of cancer, particularly in
people younger than 40 years old who undergo
multiple CT scans. However, the amount of
radiation from one test is similar to the amount
of radiation you are naturally exposed to over
one year. Talk to your doctor and the
technicians performing the test about whether
you are or could be pregnant.
Used for:
Cardiac MRI
A cardiac magnetic resonance imaging (MRI) is a
painless, noninvasive imaging test that uses
radio waves, magnets, and a computer to create
detailed pictures of your heart. No ionizing
radiation is used in this type of imaging. This
test can provide information on the type and
seriousness of heart disease to help your doctor
decide the best way to treat your condition.
Cardiac MRI can help your doctor diagnose heart
diseases or problems with the blood vessels.
Cardiac MRI can provide an accurate look at the
heart muscle, heart chamber sizes and function,
and connecting blood vessels. It is an excellent
tool to look for scarring of the heart muscle
like you might see in a heart attack, or
inflammation of the heart as you might see with
heart infection. Cardiac MRI may be performed as
a resting study or used in combination with a
stress medicine or exercise to look for low
blood flow to the heart muscle. Cardiac MRI is
also an excellent tool for evaluating tumors or
clots in the heart and to help your healthcare
provider monitor congenital heart disease or
problems with your heart valves or aorta.
Cardiac MRI may be used when images from other
studies like an echocardiogram are not clear. It
can also help clarify results from other imaging
tests such as chest
X-rays and chest
CT scans.
Cardiac MRI may be done in a medical imaging
facility or hospital. Before your procedure, a
contrast dye to highlight your heart and blood
vessels may be injected into a vein in your arm.
Some cardiac MRI studies don’t require contrast.
The MRI machine is a large, tunnel-like machine
that has a table. You will lie still on the
table and the table will slide into the machine.
Talk to your doctor if you are uncomfortable in
tight or closed spaces to see if you need
medicine to help you relax during the test. You
will hear loud humming, tapping, and buzzing
sounds when you are inside the machine as
pictures of your heart are being taken. You will
be able to hear from and talk to the technician
performing the test while you are inside the
machine. Your heart rhythm will be monitored by
an electrocardiogram, and your pictures will be
coordinated with your heart beat. The technician
may ask you to hold your breath for a few
seconds multiple times during the test.
Cardiac MRI has few risks. In very rare cases,
the contrast dye may cause an allergic-type
reaction. Talk to your doctor and the
technicians performing the test if you are or
could be pregnant or are breastfeeding. If you
are breastfeeding and need to receive MRI
contrast, you may be instructed to discard your
breastmilk for up to 2 days after the MRI study.
Tell your doctor if you have:
-
A pacemaker or other implanted device because
the MRI machine can damage these devices or
cause a metallic implant to move.
-
Had any prior surgeries, even if you do not
know if metal was involved. Metal
inside your body from previous surgeries
(for example from clips or metal parts) can
interfere with the MRI machine, cause the
metal to move, cause artifacts in your
images, or cause local heating. A lot of
surgery-related metal is safe in the MRI
machine, but it is important for the imaging
team to carefully screen you ahead of time.
-
Metal on your body from piercings,
jewelry, or some transdermal skin patches
because they can interfere with the MRI
machine or cause skin burns. Tattoos may
cause a problem because older tattoo inks
may contain small amounts of metal.
Used for:
- Arrhythmia
- Congenital Heart Defects
- Coronary Heart Disease
- Heart Attack
-
Heart Failure
- Heart Valve Disease
Carotid ultrasound
Carotid ultrasound is a painless imaging test
that uses high-frequency sound waves to create
pictures of the inside of your carotid arteries.
Your carotid arteries are the major blood
vessels that supply oxygen-rich blood to your
brain. Carotid ultrasound can help detect plaque
buildup in one or both of your carotid arteries.
It can also see whether the buildup is blocking
blood flow to the brain. If combined with
Doppler ultrasound, this test can also show how
blood is moving through your arteries.
Carotid ultrasound is usually done in a doctor’s
office or hospital. This test uses an ultrasound
machine, which includes a computer, a screen,
and a transducer. The transducer is a handheld
device that sends and receives sound waves.
You will lie on your back on an exam table for
your test. The ultrasound technician will put
gel on your neck where your carotid arteries are
located. The gel helps the sound waves reach
your arteries. The technician will move the
transducer against different areas on your neck.
The transducer will detect the sound waves after
they have bounced off your artery walls and
blood cells. A computer will use the sound waves
to create and record pictures of the inside of
your carotid arteries and to show how blood is
flowing in your carotid arteries. Test results
will help your doctor plan treatment to remove
or stabilize plaque and help prevent a stroke.
Carotid ultrasound has no risks because the test
uses harmless sound waves. They are the same
type of sound waves that doctors use to create
and record pictures of a baby inside a pregnant
woman.
Used for:
Nuclear heart scan
A nuclear heart scan is an imaging test that
uses special cameras and a radioactive substance
called a tracer to create pictures of your
heart. This imaging test can detect if blood is
not flowing to parts of the heart and can
diagnose coronary
heart disease. It also can check for damaged
or dead heart muscle tissue, possibly from a
previous heart
attack, and assess how well your heart pumps
blood to your body.
You may go to a medical imaging facility or a
hospital for a nuclear heart scan. Your
healthcare team will monitor your heart during
this test with an electrocardiogram (EKG). They
will take two sets of pictures, each taking 15
to 30 minutes. The first set of pictures is
taken right after an exercise or medicine stress
test because some problems happen only when the
heart is working hard or beating fast. Shortly
after the stress test, the healthcare provider
will inject the tracer into a vein in your arm.
You may bruise at the injection site. You will
lie still on a table that slides through a
tunnel-like machine as the first set of pictures
is taken. The second set of pictures will be
taken on either the same day or the next day
after your heartbeat has returned to normal.
Nuclear heart scans have few risks. In rare
instances, some people have a treatable allergic
reaction to the tracer. If you have coronary
heart disease, you may have chest pain during
the stress test. Medicine can help relieve your
chest pain. Talk to your doctor and the
technicians performing the test about whether
you are or could be pregnant.
Used for:
Echocardiography
Echocardiography, or echo, is a painless test
that uses sound waves to create moving pictures
of your heart. The pictures show the size and
shape of your heart and how well your heart is
pumping blood. A type of echo called Doppler
ultrasound shows how well blood flows through
your heart's chambers and valves.
Echo can detect blood clots inside your heart,
fluid buildup in the pericardium (the sac around
the heart), tumors, and problems with the aorta.
The aorta is the main artery that carries
oxygen-rich blood from your heart to your body.
Echo also can help your doctor find the cause of
abnormal heart sounds, such as heart murmurs,
due to damaged heart valves. Your doctor also
might use echo to see how well your heart
responds to certain treatments.
There are several types of echocardiography:
-
Transthoracic echocardiography is
the most common type of echo. It involves
placing a device called a transducer on your
chest after a gel is applied to your skin.
The device sends special sound waves, called
ultrasound, through your chest wall to your
heart. As the ultrasound waves bounce off
the structures of your heart, a computer in
the echo machine converts them into pictures
on a screen.
-
Stress echocardiography is done as
part of a stress test. During a stress test,
you exercise or take medicine to make your
heart work hard and beat fast. A technician
will use echo to create pictures of your
heart before you exercise and as soon as you
finish.
-
Transesophageal echocardiography gives
your doctor a more detailed view of your
heart. During this test, the transducer is
attached to the end of a flexible tube. The
tube is guided down your throat and into
your esophagus (the passage leading from
your mouth to your stomach). Your doctor
will inject medicine into a vein to help you
relax during the test.
-
Fetal echocardiography is used to
look at an unborn baby's heart to check for
heart problems. When recommended, the test
is commonly done at about 18 to 22 weeks of
pregnancy. For this test, the transducer is
moved over the pregnant person's belly.
-
Three-dimensional (3D) echocardiography creates
3D images of your heart. This may be done as
part of a transthoracic or transesophageal
echo.
You may have the echocardiography in your
doctor’s office or at a hospital. You won’t need
to do anything to prepare for most types of
echo. For a transesophageal echo, your doctor
may ask you not to eat or drink for 8 hours
before the test. Echocardiography usually takes
less than an hour to do. For some types of echo,
your doctor will need to inject saline or a
special dye into one of your veins. This makes
your heart show up more clearly on the echo
pictures.
For most types of echo, you will remove your
clothing from the waist up. Women will be given
a gown to wear during the test. You will lie on
your back or left side on an exam table or
stretcher. Soft, sticky patches called
electrodes will be attached to your chest to
allow an electrocardiogram (EKG) to be done. An
EKG is a test that records your heart's
electrical activity.
For a transesophageal echo, you’ll be given
oxygen through a tube in your nose. The back of
your mouth will be numbed with gel or spray.
Your doctor will gently place the tube with the
transducer in your throat and guide it down
until it is in place behind your heart. The
pictures of your heart are then recorded as your
doctor moves the transducer around in your
esophagus and stomach. You shouldn’t feel any
discomfort as this happens. Your throat might be
sore for a few hours after the test.
If you have a transesophageal echo, you may
experience some side effects from the medicine
given to help you relax, such as problems
breathing or nausea (feeling sick to your
stomach). Rarely, the tube used causes minor
throat injuries.
Used for:
-
Congenital Heart Defects
-
Coronary Heart Disease
-
Heart Attack
-
Heart Failure
-
Heart Valve Diseases
Electrocardiogram
An electrocardiogram, also called an ECG or EKG,
is a simple, painless test that detects and
records your heart’s electrical activity. An EKG
can show how fast your heart is beating, whether
the rhythm of your heartbeats is steady or
irregular, and the strength and timing of the
electrical impulses passing through each part of
your heart. You may have an EKG as part of a
routine exam to screen for heart disease.
An EKG may be recorded in a doctor’s office, an
outpatient facility, in a hospital before major
surgery, or as part of stress testing. For the
test, you will lie still on a table. A nurse or
technician will attach several electrodes to the
skin on your chest, arms, and legs. Your skin
may need to be shaved to help the electrodes
stick. The electrodes are connected by wires to
a machine that records your heart’s electrical
activity on graph paper or on a computer. After
the test, the electrodes will be removed.
An EKG has no serious risks. EKGs don’t give off
electrical charges such as shocks. You may
develop a slight rash where the electrodes were
attached to your skin. This rash usually goes
away on its own without treatment.
Used for:
Holter and event monitors
Holter and event monitors are small, portable
electrocardiogram devices that record your
heart’s electrical activity for long periods of
time while you do your normal activities. These
monitors can record how fast your heart is
beating, whether the rhythm of your heartbeats
is steady or irregular, and the strength and
timing of the electrical impulses passing
through each part of your heart. Information
from these recordings helps doctors diagnose an
arrhythmia, or irregular heartbeat, and check
whether treatments for the irregular heartbeat
are working.
There are many types of monitors. Most monitors
have electrodes with sticky adhesive patches
that attach to the skin on your chest. Some
monitors and electrodes used for long-term
recording may be implanted under your skin to
make it easier for you to bathe and perform your
daily activities. Your doctor will explain how
to wear and use the monitor and tell you whether
you need to adjust your activity during the
testing period.
You should avoid magnets, metal detectors,
microwave ovens, electric blankets, electric
toothbrushes, and electric razors while using
your monitor because electrical signals can
interfere with the monitor function. Usually,
you will be instructed to keep electronic
devices such as cell phones and tablets away
from the monitor and keep it dry. After you are
finished using the monitor, you will return it
to your doctor’s office or the place where you
picked it up. If you were using an implantable
recorder, your doctor will remove it from your
chest.
There is a small risk that the sticky patches
that attach the electrodes to your chest can
irritate your skin. You may have an allergic
reaction to the electrode adhesive, but the
reaction will go away once the electrodes are
removed. If you are using an implantable
recorder, you may get an infection or have pain
where the device was placed under your skin.
Your doctor can prescribe medicine to treat
these problems.
Used for:
Stress test
A stress test measures how healthy your heart is
and how well it works during physical stress.
Some heart problems are easier to identify when
your heart is working hard to pump blood
throughout your body, such as when you exercise.
Your doctor may recommend this test if you
have symptoms of a heart problem, such as
shortness of breath, chest pain, dizziness, and
a rapid or irregular heartbeat. If your doctor
does find a problem, the stress test also can
help your doctor choose the right treatment plan
and determine what types of physical activity
are safe for you.
You may do a stress test in your doctor’s office
or a hospital. The test usually involves
physical exercise such as walking on a treadmill
or riding a stationary bicycle. If you are not
able to exercise, your doctor will give you
medicine that will make your heart work hard and
beat faster, as if you were exercising. Your
doctor may ask you not to take some of your
prescription medicines or to avoid coffee, tea,
or any drinks with caffeine on the day of your
test, because these may affect your results.
Your doctor will ask you to wear comfortable
clothes and shoes for the test.
For the stress test, your doctor will put sticky
patches called electrodes on your chest and
attach a blood pressure cuff to your arm and a
pulse monitor to your finger or another part of
your body. Your doctor will measure your heart
activity and blood pressure before you start
the test.
You will slowly start to exercise on a treadmill
or stationary bicycle, and then gradually
increase the treadmill speed or bicycle
resistance until your heart is working at the
target heart rate for your age. Most often, a
stress test includes an electrocardiogram to
measure your heart’s electrical activity and
heart rate, and a blood pressure monitor as you
exercise. Your doctor may also measure your
blood oxygen level. During the test, you will
exercise for about 10 to 15 minutes. Your doctor
will stop the test if you show any sign of a
heart problem or if you are too tired to
continue the test. If you are not able to
exercise, your doctor will give you medicine
over a 10- to 20-minute period through an
intravenous (IV) line into one of your blood
vessels.
Your doctor may use echocardiography, cardiac
MRI, or a nuclear heart scan to take images of
your heart during or right after the stress
test. These tests will show how well blood is
flowing through your heart and how well your
heart pumps blood when it beats. If your doctor
also wants to see how well your body uses oxygen
you may be asked to wear a mask or mouthpiece to
measure the gases that you breathe out during
the stress test.
After the stress test, your doctor will measure
your heart activity and blood pressure to make
sure that both measurements are back within the
normal range. You should be able to return to
your normal activities right away.
Your doctor will carefully monitor you
throughout the test to lower the risk of
complications caused by the exercise or medicine
used to raise your heart rate. Intense exercise
during the test can rarely cause some heart
problems such as chest pain or irregular
heartbeats; these usually go away after
exercise. Some stress medicines temporarily
lower your blood pressure. If your doctor gives
you medicine to make your heart beat harder
instead of having you exercise, there is a small
risk of developing certain heart problems after
the test.
Used for:
- Angina (Chest Pain)
- Arrhythmias
- Coronary Heart Disease
-
Heart Failure
- Heart Valve Diseases
Coronary angiography
Coronary angiography is a procedure that uses
contrast dye, usually containing iodine, and
X-ray pictures to detect blockages in the
coronary arteries that are caused by plaque
buildup. Blockages prevent your heart from
getting oxygen and important nutrients.
This procedure is used to diagnose heart
diseases or after abnormal results from tests
such as an electrocardiogram (EKG) or an
exercise stress test. If you are having a heart
attack, coronary angiography can help your
doctors plan your treatment.
Coronary angiography is often done in a
hospital. You will stay awake, but receive
medicine to relax during the procedure. Coronary
angiography is done via a cardiac
catheterization procedure. For this, your
doctor will clean and numb an area on the arm,
groin or upper thigh, or neck before making a
small hole in the skin and a blood vessel. Your
doctor will insert a catheter tube into your
blood vessel. Your doctor will take X-ray
pictures to help place the catheter in your
coronary arteries. After the catheter is in
place, your doctor will inject the contrast dye
through the catheter to highlight blockages and
will take X-ray pictures of your heart. If
blockages are detected, your doctor may use percutaneous
coronary intervention, also known as
coronary balloon angioplasty, usually with the
use of a stent (a wire mesh that helps keep an
blocked artery open), to improve blood flow to
your heart.
After coronary angiography, your doctor will
remove the catheter and close and bandage the
opening on your arm, groin, or neck. You may
develop a bruise and soreness where the catheter
was inserted. You will stay in the hospital for
a few hours or sometimes overnight. During this
time, your healthcare team will check your heart
rate, blood pressure, and the catheter insertion
site.
Coronary angiography is a common procedure that
rarely causes serious problems. However, as with
any invasive procedure involving the heart,
there is some risk. These risks include
bleeding, allergic reactions to the contrast
dye, kidney problems, infection, blood vessel
damage, arrhythmias, and
blood clots that can trigger a heart
attack or stroke.
The risk of complications is higher in people
who are older or who have chronic kidney disease
or diabetes.
Used for:
- Arrhythmias
- Atherosclerosis
- Cardiac Arrest
- Coronary Heart Disease
- Heart Attack
- Stroke
Cardiac catheterization
Cardiac catheterization is a medical procedure
used to diagnose and treat some heart
conditions. During cardiac catheterization, a
long, thin, flexible tube called a catheter is
put into a blood vessel in your arm, groin or
upper thigh, or neck through a small incision,
or cut. The catheter is then threaded through
your blood vessels to your heart.
Used for:
- Arrhythmias
- Atherosclerosis
- Cardiomyopathy
- Coronary Heart Disease
- Heart Attack
-
Heart Failure
- Heart Valve Diseases
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