Relax! It's Just a Stress Test!

So, you are at your family doctor’s office for a routine physical and happen to mention that you have been having some chest discomfort on and off for the past month. No big deal, right? Your family physician may think otherwise. He or she now wants you to have a cardiac stress test. Is there anything routine about a routine physical? You may feel like being at the doctor’s office is a stress test in itself.

Relax! An informed patient is a comfortable patient. What is a cardiac stress test? What is involved on the day of testing? What happens after the stress test?

Whether the test is performed at a hospital, doctor’s office or an outpatient facility, all testing locations have their own specific protocols for testing, but generally incorporate the same principles.

The goal of any cardiac stress test is to detect blockage of blood vessels by dilating the blood vessels of the heart, specifically the arteries, and then observe how the heart and the body respond.  To dilate the arteries a patient must exercise to achieve a predicted target heart rate. The target heart rate is calculated as 220-age multiplied by .85. If a patient is unable to exercise, a medication may be used to dilate the blood vessels.

The two most popular types of cardiac stress tests are a regular cardiac stress test (without imaging), or a nuclear cardiac stress test (with imaging).  A regular cardiac stress test involves being placed on an EKG (heart) monitor, then exercising on a treadmill or stationary bike while being monitored by a Cardiologist or other specifically trained health care professional.

For a nuclear cardiac stress test the patient is injected with a radioactive isotope via an intravenous line (IV). Images are then obtained under a nuclear camera. While being hooked up to an EKG monitor, the patient then exercises on a treadmill or a stationary bike to achieved the predicted heart rate.  When the predicted heart is achieved, a Nuclear Medicine Technologist will inject the radioactive isotope into the patient’s I.V. while the patient is still walking on the treadmill. Nuclear images will be obtained again after the patient is off the treadmill and unhooked from the EKG monitor.

The test will be interpreted by a Cardiologist, and the results sent to your doctor. Results should be to your doctor within a week. 

Preparation is the key to having a smooth testing day. For a nuclear cardiac stress test, plan on being at the testing facility for up to three hours. The radioactive isotope needs time to circulate through your system before the images can be obtained. Do not eat or drink twelve hours before your test. This can negatively affect the nuclear images.

The most important part of the preparation is to not consume any caffeine for twelve hours prior to testing. Caffeine causes constriction of blood vessels. This will counteract the goal of the stress test.

A cardiac stress test is a safe and fairly accurate test to detect the presence of coronary artery disease. Consult your physician and talk about risk factors and testing options.