The most often used method of assessing the human cardiovascular system is the treadmill stress test. By studying the hearts performance and reaction under various levels of physical exertion, doctors are able to gage a starting point for either ruling out a cardiovascular concern or developing a diagnosis. Its reliability and/or validity are perhaps the most significant reasons why the treadmill test is so commonly part of a regular cardiovascular workup prescribed for a patient.

The treadmill stress test initially began as the simple process of checking heart rate and blood pressure during exercise. Heart rate and blood pressure were each checked before the test as the patient rested. Typically, it began with the patient beginning to walk on the machine at a slow pace, with those vitals being monitored as the walk progressed to higher paces.

If the patients vital statistics changed dramatically, causing the patient uncomfortable levels of stress the treadmill test indicated at what level of activity that stress began. An indication of no increased stress on the cardiovascular system during the patients test was generally interpreted as a sign of a healthy heart.

As research lead to advances in both medicine and technology progressed, those advances increased the effectiveness of the treadmill test in the diagnosis of cardiovascular disease. In the early 1970s, physicians began using machines that performed EKG testing simultaneously while the patient walked the machine.

Instead of only being able to monitor heart rate and blood pressure, the advanced stress test using a treadmill allowed doctors to actually view feedback of the hearts activity as the patient walked. This capacity opened a previously closed door to preventive cardiovascular care.

With health and fitness research at a premium in recent years, the stress test has become even more effective as a diagnostic tool. Nuclear medicine now stands center stage with this method of monitoring a patients cardiovascular system.

When a stress test is prescribed for a patient, he or she typically enters a hospital or clinic for an outpatient process. Upon arriving for the test, the patients vitals are checked first. He or she is then given an intravenous injection of a medication such as thallium, which is a metallic dye. 

During the treadmill stress test, the thallium or other medication used can be viewed as it is pumped through the heart, brain or other specific area of the body. This allows physicians to actually see areas of the heart, brain and/or other arteries in which blood flow is restricted.