Circulatory system

Diagnosing and treating heart disease

In order to determine your risk factors, your doctor will conduct a physical examination and will also ask whether you have a family history of coronary artery disease or other heart disease. More commonly, however, doctors require additional tests in order to diagnose heart disease. These include:

Auscultation

To determine whether you have heart disease, your doctor will do a physical examination and listen to your heart using a stethoscope. This is called auscultation. By listening to heart sounds, doctors are sometimes able to diagnose diseases affecting the heart valves.

Blood pressure

Using a blood pressure cuff, (also called a sphygmomanometer), your doctor will measure your blood pressure. The two numbers in a blood pressure reading record systolic and diastolic pressure. Systolic pressure refers to the force of blood flow through an artery when the heart beats. Diastolic pressure refers to the force of blood flow within vessels between heart beats, when the heart is at rest. A blood pressure reading shows numbers in millimetres of mercury (mm Hg) and lists systolic pressure first.¹

Electrocardiogram

An electrocardiogram measures the rate and regularity of a patient's heartbeat.

Exercise stress test

An exercise stress test shows how effectively the heart pumps at higher levels of exertion when the demand for oxygen is high. Readings from blood pressure tests and electrocardiograms are taken before, during, and after exercise to determine how the heart responds to execise. The first blood pressure reading and electrocardiogram are done to get a baseline. Readings are then taken as patients walk on a treadmill, pedal a stationary bicycle, or receive medication that increases heartbeat. The test continues until you reach a predetermined heart rate as set by your doctor. If you experience chest pain or a very sharp rise in blood pressure during the test, the test will end. Monitoring will continue for 10 to 15 minutes after completion of the test or until your heart rate returns to baseline.²

Chest x-ray

A chest x-ray is a picture of the heart, lungs, blood vessels and other organs and structures inside the chest. A chest x-ray will reveal whether your heart is enlarged and will also reveal any other abnormalities which may indicate heart disease.

Nuclear heart scan

A nuclear heart scan shows blood flow to the heart and also reveals any damage to the heart muscle. Radioactive dye such as technetium or thallium is injected into the bloodstream. A specialized camera can see the dye and identify areas of low blood flow. Nuclear heart scans are usually conducted while you are at rest and again after exercise. Patients unable to exercise receive medications that increase heart rate. The two nuclear heart scans — before and after—are then compared.³

Echocardiogram

An echocardiogram uses sound waves to create a picture of the heart. More detailed than an x-ray, the echocardiogram shows how well the heart chambers fill with blood and pump it to the rest of the body. An echocardiogram can also help identify areas of poor blood flow to the heart, areas of the heart muscle that are not contracting normally, and any prior injury to the heart caused by poor blood flow.⁴

Cardiac catheterization

In cardiac catheterization, a thin flexible catheter is passed through an artery in the groin or arm to reach the coronary arteries. This allows the doctor to determine pressure and blood flow to the chambers of the heart. It also allows the doctor to collect blood samples from the heart and to examine the arteries of the heart by x-ray.⁵

Coronary angiography

Conducted in conjuction with cardiac catheterization, coronary angiography involves the injection of dye into the catheter. Dye in the coronary arteries allows the doctor to see the flow of blood through the heart and to determine where there are blockages.⁶

Computed tomography (CT scan)

A CT scan or "cat scan" uses a large x-ray machine that uses a computer to create cross-sectional pictures of the heart while the patient lies on a scanning table that slides through the middle of the tube-like CT scanner. Once the computer has taken many cross-sectional (slice-like) images of your heart, it assembles them to make one detailed picture.⁷

Magnetic resonance imaging (MRI)

An MRI is a scan that allows your doctor to see inside the body without the need for surgery. Similar to a computed tomography, patients lie on a scanning table that slides inside a tube-like chamber. When you are placed inside the tube, you are surrounded by a magnetic field. This field reacts with magnetic elements inside your body to produce a faint radio signal. A computer then reads the radio signal and transforms it into an image that is displayed on a monitor.⁸

Your doctor may also request blood tests to check your blood cholesterol levels, blood sugar levels, levels of C-reactive protein and hemoglobin levels.

Treatment of heart disease

Heart disease may be controlled through changes in lifestyle and diet, a program of regular exercise, and heart medications. Your doctor may prescribe any one of the following to help you manage your heart condition:⁹

• Angiotensin II Receptor Blockers
• Angiotensin-Converting Enzyme (ACE) Inhibitors
• Antiarrhythmics
• Blood-Thinning Medicines
• Beta-Blockers
• Calcium-Channel Blockers
• Cholesterol-Lowering Medicines
• Digitalis Medicines
• Diuretics
• Nitrates

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1. Diagnostic Tests and Procedures. Texas Heart® Institute. (2004)
2. How is Angina Diagnosed? Diseases and Conditions Index. National Heart, Lung, and Blood Institute. US Department of Health & Human Services.
3. How is Angina Diagnosed? Diseases and Conditions Index. National Heart, Lung, and Blood Institute. US Department of Health & Human Services.
4. How is Angina Diagnosed? Diseases and Conditions Index. National Heart, Lung, and Blood Institute. US Department of Health & Human Services.
5. How is Angina Diagnosed? Diseases and Conditions Index. National Heart, Lung, and Blood Institute. US Department of Health & Human Services.
6. How is Angina Diagnosed? Diseases and Conditions Index. National Heart, Lung, and Blood Institute. US Department of Health & Human Services.
7. Computed Tomography (CT) Scan. Texas Heart® Institute. (2003)
8. Magnetic Resonance Imaging (MRI). Texas Heart® Institute. (2003)
9. Medicines for Cardiovascular Disease. Texas Heart® Institute.