Search results
Results From The WOW.Com Content Network
The majority of scans are performed using a stress/rest protocol using adenosine as the stressor which acts to induce ischaemia in the myocardium by the coronary 'steal' phenomenon. Some centers use inotrope dobutamine to stress the heart and the images are interpreted in a similar fashion to dobutamine stress echocardiogram. This article ...
Caffeine is usually held 24 hours prior to an adenosine stress test, as it is a competitive antagonist of the A2A adenosine receptor and can attenuate the vasodilatory effects adenosine. [citation needed] Aminophylline may be used to attenuate severe and/or persistent adverse reactions to adenosine and regadenoson. [39]
Rubidium-82 (82 Rb) is a radioactive isotope of rubidium. 82 Rb is widely used in myocardial perfusion imaging.This isotope undergoes rapid uptake by myocardiocytes, which makes it a valuable tool for identifying myocardial ischemia in Positron Emission Tomography (PET) imaging.
Dobutamine is a medication used in the treatment of cardiogenic shock (as a result of inadequate tissue perfusion) and severe heart failure. [2] [3] It may also be used in certain types of cardiac stress tests. [2] It is given by IV only, as an injection into a vein or intraosseous as a continuous infusion. [2]
SPECT imaging performed after stress reveals the distribution of the radiopharmaceutical, and therefore the relative blood flow to the different regions of the myocardium. Diagnosis is made by comparing stress images to a further set of images obtained at rest which are normally acquired prior to the stress images.
However, if stress imaging is normal, it is unnecessary to perform rest imaging, as it too will be normal – thus stress imaging is normally performed first. MPI has been demonstrated to have an overall accuracy of about 83% ( sensitivity : 85%; specificity : 72%), [ 13 ] and is comparable (or better) than other non-invasive tests for ischemic ...
The underlying principle is, under conditions of stress, diseased myocardium receives less blood flow than normal myocardium. MPI is one of several types of cardiac stress test. As a nuclear stress test, the average radiation exposure is 9.4 mSv, which when compared with a typical 2 view chest X-ray (.1 mSv) is equivalent to 94 Chest X-rays. [83]
Acute radiation syndrome (ARS), also known as radiation sickness or radiation poisoning, is a collection of health effects that are caused by being exposed to high amounts of ionizing radiation in a short period of time. [1] Symptoms can start within an hour of exposure, and can last for several months.