The cardiac stress test

Question:

Is a cardiac stress test better than a treadmill test? My Mom’s doctor wants her to have one because the treadmill test wasn’t good enough. What’s going on?

Answer:

By ordering a cardiac stress test, it sounds like your mom’s doctor is being vigilant about ruling out heart disease. Far too many women remain undiagnosed for heart disease by avoiding a cardiac stress test, and they miss the signs of an oncoming heart attack. Women having a Myocardial Infraction (MI) often experience symptoms different from those common in men. In a study of 515 women who had heart attacks, researchers found that 43 percent did not experience acute chest pain – a classic symptom among men. If they did feel chest pain, it came in the form of aching, tightness, pressure, sharpness, fullness, burning or tingling. The most common symptoms of heart attacks among women are: shortness of breath, weakness, unusual fatigue, cold sweats, dizziness, pain or pressure in the back or upper chest, pain or discomfort in one or both arms, a burning sensation in the chest or upper abdomen, irregular heartbeat and nausea.

According to the National Heart, Lung, and Blood Institute, heart attacks remain America’s number-one killer, and half of those who die from a heart attack are women. So it is important to take heart attack symptoms very seriously.

Chances are your mother started off with the standard ECG (“treadmill test”) for heart disease and her physician may have learned something that warrants further study through a second type of cardiac stress test. Your mom should ask her doctor why this second test has been ordered and what the doctor is looking to learn from the cardiac stress test.

Overall, cardiac stress tests evaluate how the heart responds to the stress of physical activity for the purpose of determining if there is any abnormality. Here’s a rundown of various forms of the test:

Exercise Electrocardiogram Stress Tes (ECG)t: Patients are asked to walk on a treadmill or ride a stationary bike at various levels of exertion while their heart rate and blood pressure are measured. The heart is also monitored via electrocardiogram; a cardiologist examines the ECG readings to assess changes in heart rhythm and potential decreased blood flow that can signal a blockage or other possible heart conditions.
Exercise Echocardiogram: Often referred to as an “echo test,” the exam uses ultrasound that produces images of the heart at rest and during peak exercise on a treadmill. By accurately visualizing the motion of the heart’s walls and its pumping activity under exertion, doctors are better able to see those areas of the heart that may not be getting an adequate blood supply. This also allows them to see if the heart is beating irregularly.
Nuclear Stress Test: In this test, a small amount of radioactive substance (thalium or cardiolyte) is injected into a vein. A special camera is used to see how the thalium is being absorbed. Parts of the heart that have good blood flow will collect the radioactive material and the camera will pick this up. If, however, the heart muscle shows up as a “cold spot” without any of the radioactive material, it means there is decreased blood supply, often caused by a blockage. Pictures are taken during a resting state and again following exercise so the cardiologist can see the difference.
Physiologic Stress Test: Some people are not physically able to get on a treadmill or stationary bike to perform the exertion necessary to stress the heart. Instead, they are given drugs (dobutamine and adenosine) that cause the heart to respond as if the person were exercising. While these drugs are being administered, doctors measure how the heart is responding via an echocardiogram or nuclear imaging.

If your mom agrees, it would be helpful for you to accompany her when her physician reviews the test results. When getting significant health news, everyone benefits from a second set of “eyes and ears.”