When to Undergo a Muga Scan


In the medical field, there are many different types of scanning equipment.

From X-rays to CAT scans, there are a number of different ways for healthcare professionals to make correct diagnoses.

If you’ve been to the doctor and received blood tests for something you’re concerned about, they may require you to undergo further testing. This additional testing may include a scan of some sort.

There are many different ways to look at the health of the heart. Let’s take a look at one way a doctor will scan your heart, and when you should ask for one.


Muga stands for multigated acquisition. Radionuclide angiography is a branch of nuclear medicine. This atomic medicine specializes in scans and imaging, allowing examination of the functionality of the right and left ventricles of the heart.  

This means that a doctor can execute an informed diagnostic intervention in the case of heart failure.

This heart scan involves the injection of a radiopharmaceutical into the patient, along with a gamma camera for visuals. The multigated acquisition is when the scan is triggered to take images of different points of the cardiac cycle.

There are many different names associated with muga scanning. These include gated blood pool imaging, Syma scanning, radionuclide ventriculography, and equilibrium radionuclide angiocardiography.

This particularly unique mode of imaging allows for a cine type of image of the heart beating. It will enable the person interpreting the photos to see how efficient the individual’s heart valves and chambers are as a result.

While there is now a more common scan called the echocardiogram, a Syma scan is still important and relevant. The most significant advantage that this scan has over an echocardiogram is that it’s more accurate.

muga scan - elder man going through a muga scan


Now that we’ve discussed what a muga scan is let’s talk about what patients typically need one.

Wikipedia continues by explaining that there are many different situations that require a Syma scan.

If a patient has coronary heart disease that’s either previously known or suspected, then undergoing a Syma scan can help to diagnose this disease and possibly predict any outcomes officially.  

If a patient has congestive heart failure or lesions of the heart valves, they recommend that they have a scan like this to monitor both of these conditions.

There are many different surgeries that require a Syma scan post-procedure. These include open-heart surgery, coronary artery bypass graft surgery, and percutaneous coronary angioplasty.

The reason for this is to test the efficacy of the treatment, and determine if there’s anything else that needs to be done.

If someone has a low cardiac output, then they are an ideal candidate for a Syma scan.

Often, if there are patients who are receiving cardiotoxic drugs, they are encouraged to undergo a heart scan like this to monitor any effects. These cardiotoxic drugs include immunotherapy and chemotherapy.

Lastly, if a patient has had a cardiac transplant, it’s wise that they receive a Syma scan, again for monitoring progress and assessing prognosis.


We’ve discussed who may need to get a muga scan and under what circumstances. Now, let’s explain how to prepare appropriately for a Syma scan and what you can expect afterward.  

Drugs talk about the preparation involved before a muga scan.

Generally speaking, your healthcare provider will discuss with you what to do before a heart scan. This will involve explaining what medications you may take and what you need to abstain from on the day of your Syma scan.

You may be required to avoid smoking and drinking any caffeine or liquids up to 48 hours before your heart scan. Drinks that contain caffeine include tea, coffee, and soft drinks.

You may not be able to drink anything or eat up to six hours before your Syma scan.

If your muga scan involves exercise, wear comfortable shoes and clothes. After a heart scan, you will need to drink a lot of liquids. This will encourage your body to flush out the tracer. Ask your healthcare professional about how much fluid to drink.  


We’ve discussed how to prepare for a muga scan adequately. Now, let’s look at what will happen during a Syma scan.

Drugs, say a radioactive substance, as we mentioned above, will be administered intravenously. Additionally, you will receive electrodes that the healthcare professional will place on your arms, legs and chest area.

These electrodes will connect to an EKG machine. This machine records the electrical output activity of your heart. The tracer allows for the healthcare professional to keep track of blood flow through the heart.

If you undergo a heart scan at rest, then you will be required to lie on a table while the scan takes images of your heart.

In the case of an exercise heart scan, you will be asked to ride a stationary bike or run on a treadmill for a required period.  

At the end of this period, you will lie down on a table and have pictures of your heart taken. An alternative to this is lying down on a table from the beginning and pedaling a bike that’s attached to the table.

If you’re unable to exercise, you may be asked to take medicine beforehand that increases the flow of blood to your heart. A Syma scan takes between one and two hours to complete.

muga scan - lady preparation in muga scan


Now that we’ve walked you through what happens during a muga scan let’s take a look at some possible results you may get from a heart scan like this and how these results can be beneficial to you and your doctor.

Richard N. Fogoros of Very Well Health says that there are many important things we can learn from a Syma scan.

There are several essential features of heart function that is measured by a heart scan such as this.

If the patient has previously had a heart attack, the Syma scan is able to identify which part of the heart is now functioning abnormally.

A heart scan like this localizes areas of heart muscle damage. This gives the doctor vital clues concerning which coronary artery is blocked, or even just partially blocked.  

The Syma scan is also a great way to measure the general functioning of the heart. If there is any degree of dilated cardiomyopathy present, then this is particularly valuable.

The ejection fraction of the ventricles is accurately measured and monitored by a Syma scan as well. Looking at the ejection fraction of the left ventricle is a great way to measure the overall health of a heart.


Lastly, let’s take a look at when the muga scan is more useful than other heart tests, and when it’s not.


  • Accuracy: Syma scan is capable of producing a more accurate LVEF than any other heart tests. This puts it above the rest when it comes to measuring this critical functioning of the heart.  
  • Consistency: Another reason why the Syma scan is a great way to test heart health is that it’s reproducible. This means that it is capable of reproducing the ejection fractions of the left ventricle so accurately that if there are any inconsistencies, these are more than likely medical issues to be followed up on.  


  • Radiation: Because a heart scan like this requires the use of a radioactive substance administered intravenously, exposing the patient to a tiny amount of radiation.

    The amount of radiation applied to a patient in a Syma scan is roughly twice the amount of radiation they’ll experience in a year of their life. It is ten times the amount of radiation that a patient will receive on a mammogram.  

  • Limited Information: While the Syma scan is incredibly accurate with the information it produces, this information is limited to specific areas, and functioning’s of the heart. For example, the Syma scan is not capable of giving information about the heart valves, or whether there is evidence of ventricular hypertrophy.


While there are many different heart tests available, a muga scan is a great option.

Like all heart tests, a heart scan like this has its advantages and disadvantages. It also caters to specific categories of patients, depending on their current medical condition.

A Syma scan is a vital and relevant part of cardiology, ensuring that healthcare professionals can give patients accurate diagnoses.  

Talk to your healthcare professional today about a muga scan and whether they believe it to be necessary for your circumstance.

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