I have been asked for a stress cardiac MRI, what should I know?
Stress cardiac resonance is a diagnostic test that studies the presence of ischemia or lack of blood flow in some territory of the cardiac muscle. In addition, this test also allows us to know the overall function of the heart, the presence and extent of previous infarctions and other cardiac disorders such as valve problems.
What is it about?
The patient is placed in a resonator or resonance machine for approximately 45 – 60 minutes, during which time they will be monitored and vital signs monitored. A venous line will be canalized in the arm for the administration of a drug, usually regadenoson, which will produce stress or strain on the heart in a rapid and controlled manner. Next, a small amount of special contrast for resonance is injected to visualize the areas of ischemia.
What can I notice during the test?
The drug most used for this test is called regadenoson. It is a very safe drug with few side effects. The most common are usually a sensation of temporary shortness of breath, heat, and rapid heartbeat that lasts a few seconds and does not cause any major complications.
What are the risks?
It is a very safe test and the appearance of adverse effects is extremely rare. Among those described are an allergic reaction to the drug or contrast, hypotension, chest pain, cardiac arrhythmias or seizures.
How should I prepare?
It is advisable to fast for at least 4 hours.
To achieve the maximum effect of the drug, it is advisable not to drink caffeine, chocolate or tea in the last 24 hours. Your specialist will previously ask you to suspend drugs known as beta-blockers about 48 hours before taking them.
What advantages does this test provide over others?
Other non-invasive diagnostic tests for the detection of myocardial ischemia are physical or pharmacological stress echocardiography and cardiac SPECT.
Regarding these tests, MRI provides advantages for direct visualization of the heart since it does not depend on the shape of the patient's chest or the experience of the examiner, a drawback that we may encounter in some patients when performing echocardiography.
The drug used is safer than the drugs used for pharmacological stress echocardiography.
It is an ideal test for patients who cannot exert themselves physically or cannot exert enough effort for the test to be valid.
It does not emit radiation as occurs in the case of SPECT or cardiac CT, and allows a complete assessment of cardiac function.
Therefore, stress cardiac resonance is a non-invasive, reliable and safe diagnostic test for the study of chest pain, which in addition to providing information on myocardial ischemia, allows us a complete study of the global function of the heart, state of valves and the presence of other cardiomyopathies.
By Dr. María José Romero Castro . Advanced Cardiac Imaging Unit