Laboratory tests to diagnose heart disease
The main lab tests used to evaluate you for heart disease are run on blood samples drawn from a vein in your arm. The blood samples may also be used to evaluate other bodily systems that can
affect your cardiovascular (heart and blood vessel) health. Some tests require you to fast for 12 hours before providing a blood sample, but most don’t have any dietary restrictions
Some of these tests are non-invasive, which means no instruments are inserted into the body. Other tests are invasive and require inserting instruments into the body.
Blood tests for heart disease
Your doctor may request some or all the following blood tests to check for heart disease.
- Lipid profile. A lipid profile measures your low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides and total cholesterol. Abnormal levels can elevate the risk of heart disease.
- Lipoprotein (a), or Lp (a). Lipoproteins are molecules that carry cholesterol and similar substances through the blood. A high level of one particular type, called lipoprotein (a), is considered a risk factor for heart disease. Your genes – not diet or exercise – play the main role in determining your level of Lp (a).
- C-reactive protein (CRP). Your liver produces CRP when you’re injured or have an infection. A CRP test can reveal inflammation in your body, but it cannot pinpoint the exact location or reason. Inflammation plays a central role in the process of atherosclerosis, in which fatty deposits clog your arteries.
- Homocysteine. Your body uses homocysteine to make protein and to build and maintain tissue. But too much homocysteine may increase your risk of heart disease and stroke. This test may be ordered if you have heart disease or are at high risk for developing it, or if you have a family history of heart disease but no other known risk factors.
Blood tests for different body systems
Your doctor may recommend other blood tests to understand the health of various body systems that can impact heart health. These tests may include:
Non-invasive tests to diagnose heart disease
In addition to blood tests, your doctor may recommend several non-invasive tests to check for heart disease. Non-invasive tests don’t involve drawing blood, penetrating the skin or inserting an instrument into the body.
Electrocardiogram
An electrocardiogram (EKG or ECG) is a short, painless test that records the electrical activity of your heart. Your doctor looks for specific patterns on the EKG that indicate problems such as an atrial fibrillation (an abnormal rhythm), a heart attack or signs of a previous heart attack.
Echocardiogram
An echocardiogram (also called an echo) is an ultrasound of the heart. A specially trained technician, called a sonographer, performs this test. The sonographer places a small probe called a transducer on your chest in various places. The transducer emits sound waves that bounce off various parts of the heart and return to the transducer. The time this takes is used to generate detailed images that can reveal problems such as heart valves that are narrowed or malfunctioning.
Exercise stress test
Exercise stress tests are used to see how your heart performs under physical stress. The heart can be stressed with exercise on a treadmill or a bicycle. If you cannot exercise on a treadmill or bicycle, we can use medications to speed up your heart rate, simulating the heart’s response to exercise.
You’ll wear EKG leads and wires while exercising so that the electrical signals of your heart can be recorded at the same time. We’ll also monitor your blood pressure during the test.
Nuclear stress test
Nuclear stress tests have two components: an exercise (or chemical) stress test and a heart scan combined with an injection of a radioactive substance. This substance has been used safely for many years to determine the amount of blood the heart muscle is receiving during rest and stress. The scan is done with a special camera.
Carotid ultrasound
A carotid ultrasound, or carotid duplex, is used to assess your risk for a stroke. The sonographer presses a transducer gently against the sides of your neck to obtain images of your arteries. The technician monitors your blood flow through the carotid arteries on both sides of your neck to check for abnormal narrowing of those arteries.
Abdominal ultrasound
Abdominal ultrasound is used to check for an abdominal aortic aneurysm, a ballooning weak spot in a major blood vessel (the aorta) where it runs through the abdomen. The sonographer presses the transducer against your abdomen and moves it around, observing blood flow through your abdominal aorta.
Holter monitor
A Holter monitor is a small, portable EKG device that you wear for 24 to 48 hours. It continuously records your heart's electrical activity as you go about your day. You'll keep a diary of your activities and any symptoms while you’re wearing it.
This monitor can detect arrhythmias, or irregular heart rhythms, that might not show up on a brief EKG.
Event recorder
An event recorder (also called a cardiac event monitor) is a small, portable monitor that may be worn for several weeks. This type of recorder is good for people with infrequent symptoms. When you experience symptoms, such as a pounding heart or faintness, you press the record button, and the monitor stores information about your heart's electrical activity at the time. The recordings are sent to a 24-hour monitoring station for your doctor to review.
Invasive tests to diagnose heart disease
Invasive tests are tests that require inserting needles, tubes or devices into the body.
Cardiac catheterization and coronary angiography
Cardiac catheterization is a common procedure that can help diagnose heart disease. During catheterization, the cardiologist inserts a long, flexible tube (called a catheter) into an artery in your wrist or groin. Then, they gently guide it through the blood vessel towards your heart, using X-ray guidance.
Once the catheter is in place, the cardiologist uses X-rays and other tests to evaluate whether your coronary arteries are blocked and how well your heart is working. At times, it might also be necessary to insert a small catheter into a vein to allow measurement of specific pressures in the heart and lung. This procedure can be done either through a neck vein, arm vein or groin vein.
Electrophysiology study
An electrophysiology study (EP) records the electrical activity of your heart. It helps your doctor determine the cause of a rhythm disturbance (arrhythmia) and the best treatment. During the test, your doctor may safely reproduce the arrhythmia and give you certain medications to see which one controls it best.
An EP study has two parts: recording the heart's electrical signals to assess electrical function and bringing on certain abnormal rhythms for observation under controlled conditions.
In some cases, an ablation procedure is performed at the same time to destroy any abnormal tissue that's been identified as causing the arrhythmia.