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