Treatments & Therapies

Myocardial scintigraphy – treatment, effects & risks

Myocardial scintigraphy

If the normal ECG , stress ECG and cardiac ultrasound examination ( echocardiography ) reveal unclear heart findings but no precise diagnosis can be made, myocardial scintigraphy is the method of choice. It is non-invasive and has a high informative value.

What is myocardial scintigraphy?

The myocardial scintigraphy is a gentle, nuclear medical diagnostic method to examine the blood flow , the metabolism and the mass of the heart muscle. The examination of the heart is carried out in two phases: under stress and at rest.

The findings are then compared with one another. In the scintigram , the doctor can see how circulatory disorders affect the heart muscle. The cause of the disturbed blood flow is usually the constriction of the coronary arteries . A lack of blood flow to the heart harbors the risk of a life-threatening heart attack . Myocardial scintigraphy can determine whether the extent of the circulatory disorders makes a cardiac catheterization necessary and can even spare some patients this.

Function, effect & goals

Myocardial scintigraphy allows the doctor to see the amount of blood reaching the heart at rest and under stress. By comparing the recordings, he can determine whether different areas of the heart are less well supplied with blood than others under stress. Reduced blood flow could be a sign of vasoconstriction and an increased risk of a heart attack.

If the patient has already had a heart attack, the size of the scar , the extent of tissue damage and the residual blood flow in the infarcted area can be determined. The result determines whether a bypass operation must be performed or a stent placed. In addition to these questions, myocardial scintigraphy provides information about the pumping capacity of the heart and the patient’s physical resilience, which is worse after a heart attack than in healthy tissue with a good blood supply.

For the myocardial scintigraphy, access is made to the arm vein, through which a slightly radioactive carrier substance can be injected during the stress test on the bicycle ergometer, which makes the heart vessels visible. In patients with limited physical capacity, e.g. B. due to orthopedic problems or if the blood pressure is already too high at rest, it is possible to administer medication for stress while lying down.

The stress test is controlled by a doctor and monitored by an ECG. In the phase of increased exposure, a radioactively enriched carrier substance is injected via the access. After the exertion, there is a rest phase of 30 to 60 minutes, during which the patient should eat a meal that he has brought with him, and should contain as much fat as possible. After the resting phase, pictures are taken with the gamma camera while lying down for about 20 minutes and evaluated. These recordings are used to decide whether a rest examination is necessary.

Sometimes the stress test is enough. If a resting examination is required for clarification, the radioactivity in the heart must first be broken down for about 2 hours before the second part of the examination follows. Then the same procedure follows again, only without load.

Myocardial scintigraphy is always useful to rule out coronary heart disease (CHD) if the following risk factors are still present:

Because myocardial scintigraphy determines the extent of the circulatory disorder, it can help to optimize treatment and avoid unnecessary surgical interventions. After successful treatments, it can be used as a non-invasive method to control new vascular constrictions. It can also determine an individual heart risk. The examination is offered by all statutory and private health insurance companies as a standard service.

Risks, side effects & dangers

Side effects such as allergies rarely occur with radioactive substances, more so with X-ray examinations as a reaction to contrast media . The radiation exposure is only low and is no higher than with X-rays. However, a very low risk of cancer as a late consequence cannot be completely ruled out. Therefore, the benefits and risks should always be weighed individually.

The stress phase also rarely leads to complications, even in patients with heart disease. In order to be able to ensure that the test result is as meaningful as possible, the patient must reach the highest possible level for him or her. In extremely rare cases, this can lead to cardiac arrhythmia and a heart attack. Occasionally, mild side effects such as chest tightness, a feeling of warmth, shortness of breath , a feeling of pressure in the abdomen , headache , arm and leg problems and dizziness may occur. However, these only occur when the stress is caused by medication. The radioactive substance itself does not cause any side effects.

During pregnancy , myocardial scintigraphy is only performed in exceptional cases, while breastfeeding mothers must take a two-day break from breastfeeding after the examination. In the case of severe organ diseases, the load on the cardiovascular system can be too high. Other contraindications are febrile infections, an acute myocardial infarction or severe cardiac insufficiency, uncontrollable high blood pressure, serious cardiac arrhythmias and valve defects and acute myocarditis .

For the examination, patients must be sober for at least 12 hours and are only allowed to drink a little non-carbonated water. Medications may be taken, but heart medication should be suspended for 24 hours, beta blockers even 2 to 3 days. They can be taken before the rest period if needed. Diabetics can eat a small meal that is as low in fat as possible.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.