They can spot problems early, before symptoms appear.
There are several types of heart structure tests. Each test provides unique insights into heart function, structure, and blood flow.
Some common tests include echocardiograms, CT scans, and MRIs. These tests use sound waves or imaging to create pictures of the heart.
Doctors may order heart structure tests for various reasons. They might suspect a heart problem based on symptoms or risk factors.
The tests can also track known heart issues over time. For many people, these tests bring peace of mind about their heart health.
Anatomy of the Heart
The heart has a complex structure with specialized chambers, blood vessels, and tissues that work together to pump blood throughout the body. Its anatomy is crucial for proper function and can be affected by various health conditions.
Chambers and Valves
The heart has four main chambers: two upper atria and two lower ventricles. The right atrium gets blood from the body and sends it to the right ventricle.
The right ventricle pumps blood to the lungs. The left atrium gets oxygen-rich blood from the lungs and sends it to the left ventricle. The left ventricle pumps blood to the rest of the body.
Four valves control blood flow through the heart:
- Tricuspid valve (between right atrium and ventricle)
- Pulmonary valve (between right ventricle and pulmonary artery)
- Mitral valve (between left atrium and ventricle)
- Aortic valve (between left ventricle and aorta)
These valves open and close to keep blood moving in the right direction.
Coronary Arteries and Veins
Coronary arteries supply blood to the heart muscle. The main coronary arteries are:
- Left main coronary artery
- Left anterior descending artery
- Left circumflex artery
- Right coronary artery
These arteries branch into smaller vessels that reach all parts of the heart muscle. Coronary veins drain blood from the heart tissue and empty into the right atrium.
Blockages in coronary arteries can lead to heart attacks. Doctors often check these arteries during heart tests.
Muscle Tissue and Electrical System
The heart wall has three layers:
- Epicardium (outer layer)
- Myocardium (middle layer of muscle)
- Endocardium (inner lining)
The myocardium is the thickest layer. It contracts to pump blood.
The heart's electrical system controls these contractions. Key parts of this system include:
- Sinoatrial (SA) node: the heart's natural pacemaker
- Atrioventricular (AV) node: helps signals move from atria to ventricles
- Bundle of His and Purkinje fibers: spread signals to ventricles
Problems with the electrical system can cause irregular heartbeats. Doctors use tests like ECGs to check the heart's electrical activity.
Diagnostic Imaging Tests
Doctors use special tests to see inside the heart. These tests help find problems and plan treatments.
Echocardiography
Echocardiography uses sound waves to make pictures of the heart. It shows how the heart looks and works. The test is quick and painless.
There are two main types:
- Transthoracic echocardiogram (TTE): A small device is moved over the chest.
- Transesophageal echocardiogram (TEE): A thin tube goes down the throat for a closer look.
Echocardiograms can spot: • Heart valve problems • Blood flow issues • Heart muscle damage
Doctors often use this test first because it's safe and gives lots of info.
Cardiac MRI
Cardiac MRI uses strong magnets and radio waves to make detailed heart images. It shows the heart's structure and how blood flows.
The test takes about an hour. Patients lie still in a tube-like machine. Some people feel nervous in small spaces.
Cardiac MRI helps doctors:
- See heart size and shape
- Check for scarring or damage
- Look at blood vessels
This test is very accurate. It's good for finding rare heart problems.
CT Calcium-Scoring Test
This test uses a special X-ray to check for calcium in heart arteries. Calcium can be a sign of heart disease.
The scan is fast and easy. Patients lie on a table that moves through a donut-shaped machine. It takes pictures of the heart.
A score shows how much calcium is there: • 0: No calcium (low risk) • 1-100: Some calcium (moderate risk) • Over 100: Lots of calcium (high risk)
The test helps doctors decide if more tests or treatments are needed. It's most useful for people with some risk of heart disease.
Electrophysiology Tests
Electrophysiology tests help doctors check the heart's electrical system. These tests can find problems with heart rhythms and guide treatment plans.
Electrocardiogram (ECG)
An ECG records the heart's electrical signals. It's a quick, painless test done in a doctor's office or hospital. Sticky patches called electrodes go on the chest, arms, and legs. These connect to a machine that makes a graph of the heart's activity.
ECGs can spot:
- Irregular heartbeats
- Heart attacks
- Blocked arteries
- Thickened heart muscle
The test takes about 5-10 minutes. Patients lie still and breathe normally.
ECGs help diagnose many heart issues and are often the first test doctors use.
Holter Monitoring
A Holter monitor is a portable ECG. Patients wear it for 24-48 hours or longer. It records heart activity during daily life.
The device is about the size of a small camera. Wires connect it to electrodes on the chest. Patients keep a diary of activities and symptoms.
Holter monitors can catch irregular heartbeats that don't show up on a standard ECG. They help doctors see how the heart responds to:
- Exercise
- Stress
- Sleep
This test is useful for finding the cause of symptoms like dizziness or fainting.
Event Recorders
Event recorders are similar to Holter monitors but are used for longer periods. Patients can wear them for weeks or months.
There are two main types:
- Continuous recorders: Always on, like Holter monitors
- Symptom-activated recorders: Patients press a button when they feel symptoms
Event recorders are good for catching rare heart rhythm problems. They help when symptoms don't happen every day.
Patients can do normal activities while wearing the device. They send the data to their doctor through a phone or internet connection.
Blood Flow Evaluation
Blood flow tests check how well blood moves through the heart and blood vessels. These tests help doctors find problems and decide on treatments.
Stress Tests
Stress tests show how the heart works during exercise. A person walks on a treadmill or rides a stationary bike. Doctors watch their heart rate, breathing, and blood pressure.
There are different types of stress tests. Some use pictures of the heart. Others use medicine to make the heart work harder.
Stress tests can find:
- Blocked arteries
- Heart rhythm problems
- How well the heart pumps blood
These tests are safe for most people. They take about an hour to complete.
Cardiac Catheterization
Cardiac catheterization looks inside the heart's blood vessels. A doctor puts a thin tube into a blood vessel in the arm or leg. They move it to the heart.
The tube can:
- Measure pressure in heart chambers
- Take blood samples
- Find blockages in arteries
Doctors may also use it to:
- Open blocked arteries
- Fix heart valves
- Take small pieces of heart tissue
This test takes 30 minutes to a few hours. People usually go home the same day.
Myocardial Perfusion Imaging
Myocardial perfusion imaging checks blood flow to the heart muscle. It uses a small amount of radioactive dye and special cameras.
The test has two parts:
- Rest scan
- Stress scan
Doctors compare the two scans to see how blood flows when the heart is working hard and when it's at rest.
This test can:
- Find areas of poor blood flow
- Check for heart attack damage
- See how well treatments are working
The whole process takes 3-4 hours. The radioactive dye is safe and leaves the body in a day or two.