To diagnose heart disease, a healthcare professional examines you and listens to your heart. You are usually asked questions about your symptoms and your personal and family medical history. Sometimes heart disease may be "silent" and not diagnosed until a person experiences signs or symptoms of a heart attack, heart failure, or an arrhythmia.

Tests

Many different tests are used to diagnose heart disease.

• Blood tests. Certain heart proteins slowly leak into the blood after heart damage from a heart attack. Blood tests can be done to check for these proteins. A high-sensitivity C-reactive protein (CRP) test checks for a protein linked to inflammation of the arteries. Other blood tests may be done to check cholesterol and blood sugar levels.
• Chest X-ray. A chest X-ray shows the condition of the lungs. It can show if the heart is enlarged.
• Electrocardiogram (ECG or EKG). An ECG is a quick and painless test that records the electrical signals in the heart. It can tell if the heart is beating too fast or too slow.
• Holter monitoring. A Holter monitor is a portable ECG device that's worn for a day or more to record the heart's activity during daily activities. This test can detect irregular heartbeats that aren't found during a regular ECG exam.
• Echocardiogram. This noninvasive exam uses sound waves to create detailed images of the heart in motion. It shows how blood moves through the heart and heart valves. An echocardiogram can help determine if a valve is narrowed or leaking.
• Exercise tests or stress tests. These tests often involve walking on a treadmill or riding a stationary bike while the heart is checked. Exercise tests help reveal how the heart responds to physical activity and whether heart disease symptoms occur during exercise. If you can't exercise, you might be given medicine that affects the heart like exercise does.
• Cardiac catheterization. This test can show blockages in the heart arteries. A long, thin flexible tube called a catheter is inserted in a blood vessel, usually in the groin or wrist, and guided to the heart. Dye flows through the catheter to arteries in the heart. The dye helps the arteries show up more clearly on X-ray images taken during the test.
• Heart CT scan, also called cardiac CT scan. In a cardiac CT scan, you lie on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around your body and collects images of your heart and chest.
• Heart magnetic resonance imaging (MRI) scan. A cardiac MRI uses a magnetic field and computer-generated radio waves to create detailed images of the heart.