Download - Cardiac Procedures
Cardiac ProceduresNuclear Cardiac ScanEchocardiographyDoppler Ultrasound
Nuclear Cardiac Scan
Nuclear Cardiac Scan• Nuclear cardiac scans use a radioactive substance
called a tracer (usually thallium) to study how blood flows in the heart and body
• Advantage over MRI, X-ray or CT scans▫Ability to measure and present metabolic functional
information instead of only being able to produce structural information of the heart
• There are two main types of nuclear cardiac scans ▫Single positron emission computed tomography
(SPECT)▫Cardiac positron emission tomography (PET)
No clear cut advantage of using one over the other in all situations
Single Positron Emission Computed Tomography (SPECT)• SPECT is the most well-
established and widely used test for diagnosing coronary artery disease (CAD)▫ Shows problems with blood flow
to the heart that can be detected only when the heart is working hard and beating fast
• Depicts how well the heart's left ventricle pumps blood to the body▫ Weak pumping ability may be the
result of heart attack or failure• Most commonly used tracer in
SPECT is thallium-201• SPECT scans are more cost
effective and therefore more available than PET scans
Cardiac Positron Emission Tomography (PET)• PET scan is able to penetrate
through thick layers of tissue much easer than a SPECT scan▫ Provides more detailed, clearer
pictures of the heart▫ Better at showing whether
CAD is affecting more than one of the heart's blood vessels
• Uses different tracers than SPECT
• Newer technology that is often cost prohibitive and less available▫ PET requires high-end
computers to process information gathered
Nuclear Cardiac Scan
• During procedure, patient lies very still on a padded table while a gamma camera takes pictures of the heart from various positions around the body ▫ First set of pictures is
taken right after a stress test
▫ Second set of pictures is taken 2-3 hours later, when heart is at rest and beating at a normal rate
• Scan can take between 2 to 5 hours in a single day
Nuclear Cardiac Scan
•Most useful for:▫Diagnosing coronary artery disease▫Determining location and extent of
damaged heart muscle▫Evaluate the extent of a coronary artery
blockage•Risks
▫Not recommended for pregnant women due possible harm to baby from radioisotopes
Echocardiography
Echocardiography
•Test that uses sound waves to create images of the heart▫ Provides information on the size,
structure, and movement of the different parts of the heart
•Two examples of echocardiography tests▫Transthoracic echocardiography▫Transesophageal echocardiography
Used when a more detailed view of the heart is necessary
▫Tests take about an hour to complete
Transthoracic Echocardiography
• During procedure, the patient lies on his back or left side
• EKG electrodes are attached to the chest with stickers to perform EKG
• A gel is applied to chest▫ helps sound waves reach the
heart• A wand-like device (transducer)
is placed on the chest and moved around, transmiting ultrasound waves into the chest ▫ Echoes from the sound waves
are converted into pictures of the heart on a computer screen
• Performed by sonographer
Transesophageal Echocardiography
• Same technology as transthoracic, but the transducer is attached to the end of a flexible tube▫ Tube is guided down the
throat and into the esophagus
• Patients are generally given medicine through an IV to prevent anxiety during the test
• Provides more detailed images▫ 3D images now possible
• Performed by a doctor
Echocardiography
•Useful in diagnosing:▫Enlarged heart▫Heart failure▫Damage to the heart muscle ▫Coronary artery disease (CAD)▫Valve problems▫Structural abnormalities ▫Blood clots
Doppler Ultrasound
Doppler Ultrasound
•Type of echocardiography test which visualizes the movement of blood through the heart & blood vessels▫Bounces high-frequency sound waves
(ultrasound) off red blood cells Movement of blood cells causes a change in
pitch of the reflected sound waves (known as the Doppler effect) If there is no blood flow, the pitch does not
change
▫Noninvasive, low risk
Doppler Ultrasound
• During the procedure, the sonographer presses a small hand-held device called a transducer against the skin over the area of the body being examined, moving from one area to another as necessary▫ Gel has been topically
applied to area to help amplify sound waves deeper
Doppler ultrasound
•Conditions diagnosed with Doppler ultrasound▫Heart valve defects and congenital heart
disease▫Blocked artery (arterial occlusion)▫Narrowing (stenosis) of an artery▫Bulging arteries (aneurysms)▫Poorly functioning valves in leg veins, causing
blood or other fluids to pool in the legs (venous insufficiency)
▫Decreased blood circulation into the legs (peripheral artery disease)
▫Blood clots