Stress testing is primarily used to determine if there are any blockage in the blood vessels to the heart which interfere with blood flow to the heart. Some types of stress tests are also used for evaluating the function of the heart valves.
Treadmill exercise stress test:
This requires the patient to exercise on a treadmill. Presence of absence of problems with blood flow is determined by monitoring the patient’s EKG.
Exercise Nuclear stress test:
This consists of the patient exercising on a treadmill in addition to which nuclear material is injected through an IV to visualize the relative blood flow to various parts of the heart.
Chemical Nuclear stress test:
This is different from a Exercise Nuclear Stress test on that the patient does not walk on a treadmill. Instead, a number of different chemical agents can be used to simulate the relative effects of exercise on the heart.
Exercise Stress Echo:
This test requires the patient to exercise on a treadmill. Echocardiogram is used to compare the movement of various segments of the heart muscle before and after exercise. Presence of certain changes may be suggestive of significant blockages in the blood vessels to the heart.
Chemical Stress Echo:
This similar to an Exercise Stress Echo, except that instead of the patient walking on the treadmill an intravenously administered drug is used to simulate the relative effects of exercise on the heart.
This test consists of injecting contrast (dye) material into the blood vessels of the heart and taking X-ray picture. This enables the physician to see any blockages in the blood vessels. Heart catheterization also allows the doctor to measure the pressure inside the various chambers of the heart and to determine the pumping capacity of the left ventricle. To reach the heart a short plastic tube referred to as a “sheeth” is placed the femoral artery (the artery in the groin). Long hollow plastic tubes referred to as catheters are then threaded over a wire to reach the heart and inject contrast into the blood vessels.
This is another way to visualize the anatomy of the blood vessels to the heart. Contrast is injected through and IV and pictures of the blood vessels of the heart are obtained by a CT scan.
Echocardiogram is an ultrasound generated moving picture of the heart. This test enables the physician to see the various chambers of the heart to assess the size and function of these chambers. Similarly, the function of the valves are also evaluated by the echocardiogram.
EKGs are obtained by placing six sticky leads on the left chest and one lead on each arm and each leg which are then used to generate a snap shot of the electrical activity of the heart. This enables the physician to determine the heart rhytem and also provides information about possible old heart attacks or an ongoing heart attack.