What is heart scintigraphy?
Myocardial scintigraphy combined with ergometry or a pharmacological (medicinal) stress test, is the most sensitive non-invasive test to identify and locate reduced blood flow to the heart muscle (Ischaemia). Furthermore it plays a role in the risk assessment of patients with suspected or known coronary heart disease and in the assessment of myocardial vitality (viability of heart muscle tissue) following an infarct.
Different radiopharmaceuticals and study protocols are used. Usually a pharmaceutical marked with technetium 99m (99mTc) (e.g. MIBI or tetrofosmin) is injected at the time of the greatest physical stress or after administering regadenoson (vessel enlarging medicine). Shortly after the scintigraphy commences (strain examination = stress examination).
Recordings at rest are prepared about 60 minutes after recordings in a state of stress or even on another day. Normally scintigraphy is performed using tomographic examination technology (detector head of the gamma camera rotates around the patient).
The recording takes about 20 minutes but the entire examination requires an absence of about 3 hours (waiting time between the individual scintigraphy examinations - stress recording and rest recording – need not be in the Clinical Department for Nuclear medicine).
Interaction with other medication.
Beta-Blockers impair ergometry, depending on the half-life of the radiopharmaceutical they should be taken up to three days before the test.
Medications containing caffeine or xanthine such as aminophylline, euphyllin, theospirex, spiropent, as well as coffee, tea, chocolate or cola drinks interfere with regadenoson as pharmacological test.
The patient should fast for the examination.
Risks (undesirable side effects)
No severe reactions have been described until now with technetium-99m marked radiopharmaceuticals. The main risk is related to the physical or pharmacological stress (rhythm disorders, heart infarction, although serious events very seldom occur, 1-10 of 100 000 examinations), stress-induced ischaemic events must be considered if necessary. The ability to drive is not influenced by this test.
The radiation load is in the medium range in the spectrum of nuclear medicine examinations.
Myocardial perfusion agents infiltrate breast milk. Any interruption to breastfeeding should be discussed with the staff of the nuclear medicine department.
Non-invasive identification of ischaemia in patients with chest complaints
Residual stress ischaemia following a myocardial infarct
Follow-up examinations after angioplasty or bypass operation.
Non-invasive search with suspected re-stenosis of a dilated or operated coronary vessel.