Cardiac stress determination or stress echo is done to investigate underlying coronary artery disease. It helps determine blood flow and the pumping rate of the heart. The preliminary tests performed before stress echocardiography include the assessment of ventricular function, wall motion thickness and aortic root. These tests indicate cardiac conditions along with ischemic heart disease and other cardiac conditions. Stress echocardiography is recommended over pharmacological assessment, because of its advantage in describing the cardiac performance during the test through images. Pictures are taken of your heart before and after exercise to check the efficiency of the heart.
Stress echocardiography is carried out on a treadmill or by a bicycle in a supine position. A work load of 25W is given initially with subsequent rise in intensity. Stress echocardiography also determines the aerobic capacity. The use of bicycle exercise has an advantage as it gives the Doppler information of the test. This provides information about the blood flood through the heart's pumping chambers and valves. Stress echocardiography has been extensively used in the risk evaluation for coronary artery disease even in patients who are asymptomatic. The usual protocol followed for the test is fasting for at least three hours before the test is performed.
Before commencing the stress test, your blood pressure and electrocardiogram (EKG) is also done. The stress echo is taken during the rest phase, stress phase and a repeat when the heart is still beating fast. Pregnant women are not advised to undergo this test. You will be connected to an ECG monitor to record the heart activity through small electrodes. Stress echocardiography is beneficial for physicians to determine the treatment options for asymptomatic conditions pertaining to coronary artery disease. It also aids the detection of angina or chest pain in the patients and also conditions like cardiomegaly and myocardial infarction.
SPECT or Single Photon Emission Computed Tomography is a diagnostic tool that that uses gamma camera to collect gamma rays that are emitted from the patient. Radioactive isotope is administered to the patient either as injection or inhalation or ingested liquid. SPECT imaging helps acquire multiple images from multiple angles. The gamma camera is rotated around the patient. Dual-headed cameras can help in accelerating the test. Often triple-headed cameras are also used. SPECT is particularly useful in imaging of tumors, bones, thyroid and infections. Cardial imaging and brain imaging provide critical information about localized functions. MPI (Myocardial perfusion imaging) is an important cardiac stress test. SPECT images allow diagnosis of ischemic heart disease. This test is comparable to stress echocardiography. SPECT imaging of the brain aids in distinguishing Alzheimer's disease from other vascular dementia. Nearly 30 or more images are taken of the specific body area that is being viewed. SPECT scanning is time consuming.
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Collection of Pages - Last revised Date: February 18, 2018