Nuclear Stress Test versus Echocardiogram

April 7, 2010

With the ever increasing rise in the number of weak heart conditions faced all over the world, it is important to understand the amount of stress and workload your heart can take at all times. Nuclear stress tests are an increasingly popular test, and focused primarily on gauging the hearts capacity to handle these stressful situations. These stress tests will determine whether the functioning of the blood vessels are normal or whether there is any dead tissue present in the heart that may prevent it from pumping the blood effectively. Nuclear stress tests, also known as thallium tests incorporate the use of a radioactive substance being injected into the patient. The radioactive substance then accumulates in the heart, thereby allowing images of the functioning of the heart. This is captured with the help of gamma cameras during a state of rest or even a period of substantial stress. The entire medical test relies on the fact that during a period of exercise, the blood vessel will increase in diameter allowing more blood to flow through. However, in instances where there is a blockage of some sort, the narrowed blood vessel does not allow enough blood to flow through. As a result, the area or the heart that is being supplied by a fully operational blood vessel will accumulate more isotopes and therefore appear much darker on the images relayed onto the monitor present in front the attending physician. The areas of the heart that are not receiving the optimal amount of blood supply will collect less isotopes and therefore appear as much lighter regions on the monitor.

Some of the symptoms that would determine the requirement for a nuclear stress test include suffering from conditions like diabetes, increased blood pressure and any signs of coronary artery disease.

On commencement of the test, a number of wires extending from an ECG machine are connected to various points on the patient's chest so as to measure the patient's blood pressure and heart rate. Initially, readings of the patient's statistics will be taken while the individual is in a state of rest. The patient will then be asked to perform some low intensity physical activity. After a period of about 20 minutes, the patient will be asked to lie down and further images of the heart are captured before another period of about 3 to 4 hours of rest is suggested. The patient will be asked to avoid consumption of coffee, tea and sodas during this period and another vial of dye is injected into the system and more images captured. These sets of images are then studied by the doctor to help him or her form an informed opinion.

Submitted by M T on April 7, 2010 at 10:59

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