By James M. Rippe

Diagnostic tests exist for almost all cardiac risk factors and heart conditions — often in what seems a bewildering variety. What’s the primary purpose of such tests?

In the broadest sense, these tests are designed to help healthcare professionals get a better understanding of heart conditions and heart health in individuals who may be experiencing symptoms of possible heart problems or to evaluate individuals who have such high risk of heart problems that further testing is warranted.

Knowing more about the ten test procedures presented here will prepare you to work with your doctors to make the choices that are right for you.

Blood tests to determine CHD risk

In a regular checkup or follow-up visit, your physician typically orders a variety of basic blood analyses that are performed using one or two vials of blood drawn after you’ve been fasting for 8 to 12 hours. These tests are inexpensive and provide very good evaluation insights for your doctors. Tests that directly relate to the heart and cardiovascular system include the following:

  • Lipid profile or lipid panel: This test is an analysis of cholesterol, HDL and LDL cholesterol, and triglycerides.

  • Complete blood count (CBC): This test provides an analysis of various components of the blood, such as red and white blood cells. The CBC is used to diagnose anemia and to point to the need for other tests.

  • Glucose level: This test serves as an analysis of insulin resistance and the possible presence of diabetes mellitus. Because insulin resistance and diabetes are risk factors for coronary heart disease (CHD), your physician closely monitors this result.

  • A basic or comprehensive metabolic panel: This test provides an analysis of various factors related to kidney function, liver function, and electrolytes, which can be related to heart disease.

  • Thyroid level: Your physician monitors this test for evidence of an overactive or underactive thyroid because such conditions can cause your heart to beat too rapidly or to increase the risk for CHD.

  • High sensitivity C-reactive protein (hs-CRP): If you are at high risk of CHD or already have heart problems, your physician may wish to order this blood test, which detects inflammation in the blood vessels. Another inflammatory marker that your physician may choose to check is levels of fibrinogen.

Electrocardiogram (ECG)

Invented more than 100 years ago, the electrocardiogram (also called ECG or EKG) represents cardiology’s first high-tech tool. But this graphic recording of the heart’s electrical impulses remains one of the most useful tests. Many doctors include it as part of a routine annual physical exam to assess any potential heart problems. Most importantly, the ECG is an early diagnostic step taken when an individual exhibits symptoms that may indicate heart disease.

Exercise stress test

An exercise stress test, also called an exercise tolerance test, is an electrocardiogram that’s administered while the heart is beating fast during exercise. After you’re properly wired up, you’re asked to walk and/or run at progressively higher speeds on a motorized treadmill or to pedal against steadily increasing resistance on a stationary cycle. These exercise activities cause the heart to speed up.

Among the most important clinical information that this test reveals is whether adequate blood flow is reaching the heart during exercise. Thus, the exercise tolerance test is extremely useful for people who have chest pain or other cardiac symptoms in making the diagnosis of coronary heart disease (CHD), angina, and in some instances, unstable angina.

It may also be used for people with risk factors such as obesity, diabetes, or high blood pressure before beginning an exercise program. Appropriate use criteria suggest it is rarely appropriate for low-risk individuals who have no symptoms.

Echocardiogram

An echocardiogram, which also goes by the names cardiac sonogram and cardiac ultrasound, is a noninvasive test. It bounces sound waves off various structures of the heart. Sound waves are sent out by and then return to a device known as a transducer, which then converts them into a moving picture of all the structures of the heart.

Echocardiography gives a good picture of how well the heart is pumping blood, the condition and functioning of the heart valves, and whether there is any heart enlargement or thickening of the muscle walls. Echocardiograms are very useful for evaluating problems related to heart failure and atrial fibrillation as well as valve functioning.

However, guidelines indicate that this test is rarely appropriate for healthy individuals who have no symptoms and have a low risk of CHD as measured by a valid global risk assessment tool.

Coronary calcium scan

Calcium in the arteries of the heart is an indication of atherosclerosis, the plaques that narrow the coronary arteries causing CHD. Finding calcium in the coronary arteries is useful in the early diagnosis of heart disease in individuals who are at moderate risk of heart disease, regardless of whether they have symptoms or not.

Typically, moderate risk means having a 10 percent to 20 percent change of having a heart attack in the next ten years, based on a validated assessment tool. ACC and AHA guidelines do not recommend this test for routine screening for heart disease in individuals who have no symptoms and are at low risk.

The coronary calcium scan, also called coronary calcium scoring, uses computed tomography (often called a CT scan or CAT scan). CT scanning uses high-speed X-rays to create very precise images of the heart and large vessels leading to the heart. Because CT scans use radiation, pregnant women shouldn’t have them.

Cardiac MRI

Cardiac magnetic resonance imaging (MRI) uses large magnets to create a powerful magnetic field that produces three-dimensional images (still and moving) of the heart and its structures. In recent years, research has increased the ways to use MRIs to help diagnose coronary heart disease as well as to indicate the condition of the heart muscle and the damage from a heart attack.

However, because of the intense magnetic field, if you have a medical device such as an implanted defibrillator or pacemaker, MRIs are usually not for you.

Angiography

When a contrast material (often called a dye) is injected through a catheter to make arteries or other structures of the heart visible to X-rays, the procedure is called angiography. An advanced procedure, it usually is performed in a heart catheterization laboratory by a cardiologist who specializes in the field. Patients undergo heart catheterizations to provide definitive evidence of any abnormalities that may be present

As a diagnostic test, heart catheterization is typically used when another less invasive cardiac test has indicated the probability of serious problems such as blocked coronary arteries. It is often used for this purpose in the presence of unstable angina or a heart attack to identify blockages. Heart catheterization is a very serious procedure, and your doctor will discuss the reasons, benefits, and risks of it carefully with you.

Carotid artery ultrasound

The carotid arteries run up either side of your neck and carry oxygenated blood to the front of the brain. Atherosclerotic plaque narrowing these arteries is a risk factor for stroke.

Many direct-to-consumer “preventive screening” companies advertise these scans as a way to “put your mind at rest” or, should the ultrasound indicate narrowings, save you from a stroke. Unfortunately, to date there is inadequate evidence that such screenings in individuals without symptoms actually reduce strokes or save lives. In fact, such screenings produce a number of false positives.

Abdominal aortic aneurysm ultrasound

An aneurysm is a bulge in the wall of a blood vessel. An aortic aneurysm occurs in the aorta, the large vessel that carries oxygenated blood from the heart to the rest of the body. Ruptured abdominal aortic aneurysms (AAA) are the primary cause of death in between 10,000 and 11,000 deaths a year in the U.S.

AAAs are most likely to occur in older white men who have ever smoked. Family history of AAA may also up the risk. For this reason, preventive guidelines recommend that men between 65 and 75 who are current or former smokers receive one ultrasound screening. Many direct-to-consumer screening companies also actively advertise this screening test to the general public.

The guidelines, however, also recommend that the screening take place in an accredited facility with technologists who have appropriate credentials. If you think you may be at risk of AAA, discuss screening with your doctor.

Other cardiac tests

These cardiac tests just touch on the many tests that exist for cardiac and other health issues. You can find out more about cardiac tests at several reliable websites, including the following: