Are you having back pain with any of the following?

  • Severe pain, weakness or tingling in your leg(s).
  • Difficulty stopping urination or loss of control of bladder or bowels.
  • Unexplained fever, nausea or vomiting.
  • A history of cancer or unexplained weight loss.

We understand that you are experiencing one or more of the health issues that might be impacting your back pain.

We recommend that you discuss these health issues with your doctor before proceeding with this program.

Once you are cleared by your doctor to do this program, we hope it helps you find relief from your back pain.

Provider photo for Jeremy Swartzberg

Jeremy Swartzberg, MD

Hospital Medicine

Welcome to My Doctor Online, a web site that my colleagues and I developed to make it easier for you to take care of your healthcare needs. On this site you will find answers to many of your questions about my clinical practice. Also included are several online features that will allow you to e-mail me, check your laboratory results and refill prescriptions. I hope you find its content informative and useful.

My Offices

Oakland Medical Center
Appt/Advice: 510-752-1190

See all office information »

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Nuclear medicine heart studies (heart scans) are used to assess heart health. We will:

  • Inject a safe amount of radioactive material (tracer) into your bloodstream. The tracer then travels to your heart. 
  • Use a special camera to create pictures of the heart and nearby blood vessels.

Your scan results help us detect whether your heart:

  • Has plaque buildup in the arteries (coronary artery disease).
  • Has muscle tissue damage from a heart attack.
  • Is pumping effectively.
Additional References:


The 2 main types of nuclear medicine heart studies are:

  • Myocardial perfusion scan (nuclear stress test). This test measures blood flow through the heart muscle (myocardium). As healthy tissue absorbs the tracer, we can clearly see the heart areas that aren’t getting enough blood. 
  • Multigated acquisition (MUGA) scan (cardiac blood pool scan or radionuclide angiogram). A MUGA scan measures how well the heart pumps blood. 

The heart’s lower chambers (ventricles) are the pumps, with the:

  • Right ventricle pumping blood to the lungs to receive oxygen. 
  • Left ventricle pumping oxygen-rich blood out to the body. 

We measure the percentage of blood pumped (ejected) out of the heart with each beat (ejection fraction). This shows how effectively your heart is pumping. 

During either type of scan, pictures are taken when the heart is at rest and beating at its normal rate. 

Some heart problems occur only when the heart is working hard. We may need to take another series of pictures after you take medication or during an exercise or stress test.

Additional References:

Why It Is Done

We can use a myocardial perfusion scan to detect:

  • Cause(s) of chest pain.
  • Heart muscle damage due to a heart attack.
  • Coronary artery disease (CAD) and the extent of blockage.
  • Congenital heart defect and its severity.

Your heart scan results help us determine whether your:

  • CAD should be treated with angioplasty, coronary artery bypass grafting (CABG), or another option.
  • Chest pain and shortness of breath are due to insufficient blood flow, after your angioplasty or another artery-opening procedure.
  • Next treatment step should be cardiac catheterization with coronary angiography, or another diagnostic procedure.

The scan also helps us assess:

  • Your risk for a heart attack and best treatment options.
  • Safe physical activity for you.

We can use a MUGA scan to:

  • Detect enlarged ventricles.
  • Measure the ventricles’ pumping action (ejection fraction).
  • Check for abnormal flow of blood through the heart.

This scan can also help us detect:

  • Heart function before and after a heart transplant or other heart surgery.
  • A bulge in the ventricular wall (aneurysm) that can occur after a heart attack. 

MUGA scans are also used during and after cancer chemotherapy. Some chemotherapy drugs can damage the heart and lead to congestive heart failure. 


Nuclear medicine heart studies are generally safe. Complications are rare. We’ll talk with you about possible risks before the test.

You’ll be exposed to a very small amount of radiation from the tracer injected into your bloodstream. No long-term effects have been reported from this exposure.

Radiation exposure can harm a developing fetus or baby. If you’re:

  • Pregnant or may be pregnant, you shouldn’t have a nuclear heart scan.
  • Breastfeeding, it’s important to tell us. We’ll talk with you about using formula and throwing away breast milk for 1 to 2 days after the test. This ensures that the tracer won’t contaminate your breast milk.

Rarely, people have an allergic reaction to the tracer.

During the stress test part of a scan, you may:

  • Have chest pain, if you have coronary artery disease. 
  • Faint.
  • Have an irregular heartbeat. 

There’s a rare chance of having a heart attack.

After your stress test, call 911 immediately, or have someone drive you to the nearest hospital, if you have:

  • Chest pain.
  • Trouble breathing.
  • Other serious symptoms.

How You Prepare

When you talk with your doctor about a myocardial perfusion scan or MUGA scan, be sure to let them know whether you have:

  • Health problems, such as diabetes
  • A pacemaker or other device in your chest
  • Any allergies

Also tell your doctor if you are or may be pregnant or are breastfeeding.

Follow all of the instructions your doctor gives you to prepare for your heart scan. The instructions will include:

  • Medications to take or stop taking.
  • When to stop eating and drinking, if necessary.
  • Other activities and substances to avoid before the test.
  • Other steps to take.

Being prepared is especially important if your scan includes a stress test. Wear comfortable clothes and running or walking shoes.

A myocardial perfusion scan can take up to 4 hours. Please bring:

  • Reading material or another activity for the waiting periods.
  • A snack for after the test. You’ll need to fast before the test.

What to Expect

Knowing what to expect during a heart scan can help you feel more comfortable with the process.

Myocardial perfusion scan

Usually, 2 image series of your heart are taken over 4 hours on 1 day (or on 2 separate days). We take:

  • One series while the heart is at rest (rest scan).
  • Another series after the heart is stressed by exercise or medication (stress scan). 

For the stress scan, your heart will be working hard for 15 minutes or less. We take the image series 15 to 30 minutes after we inject the tracer.

If we do the stress scan first, you’ll rest for 30 minutes to 2 hours before we do the rest scan.

After your stress scan, you may:

  • Feel tired and have muscle aches, if you exercised.
  • Have mild side effects, such as nausea and headache, if you took medication.
Multigated acquisition (MUGA) scan

This test usually takes 1 to 2 hours.

Sometimes, we do a stress MUGA scan to measure how well the heart pumps during exercise.

After your heart scan 

It’s usually fine to resume your normal activities right away. 

Help flush the tracer out of your body more quickly by:

  • Drinking plenty of fluids.
  • Emptying your bladder often.
Additional References:


We’ll talk with you about your scan results and next steps.

Myocardial perfusion scan

We usually have your results within 3 days.

We compare the images of your heart at rest and after stress. This tells us whether blood flow is restricted only when you’re physically active. 

A normal test result may show that:

  • The tracer is evenly distributed throughout the heart muscle during rest and exercise.
  • There are no abnormal areas.

These results mean you’re unlikely to have coronary artery disease. You may not need further tests.

An abnormal test result may show that your heart was damaged by a heart attack, or that blood flow to your heart is:

  • Reduced during exercise and normal during rest. 
  • Limited by coronary artery blockage during exercise.
  • Poor during both rest and exercise. You may have severe CAD or have had a heart attack.

You may need additional tests or procedures, such as cardiac catheterization (angiography).

MUGA scan

Normal results can mean that your:

  • Ejection fraction is between 50 and 70.
  • Heart muscle walls move normally during contraction.
  • Ejection fraction either increases or doesn’t change during the stress scan, compared to the rest scan.

Abnormal results can indicate these conditions.

1. Ejection fraction is low. If your score is:

  • Between 40 and 50, you may have heart valve disease, heart attack damage, or another problem.
  • Below 40, you may have heart failure or cardiomyopathy. 
  • Below 35, you’re at risk for a life-threatening irregular heartbeat (arrhythmia).

2. Ejection fraction is too high. A score above 75 may mean you have hypertrophic cardiomyopathy or another condition.

3. Ejection fraction goes down during the stress scan compared to the rest scan. You may have CAD.

4. Slow movement (hypokinesis) or lack of movement (akinesis) in areas of the heart. You may have muscle damage or lack of blood flow.

5. Tracer is not evenly distributed in the heart. You may have CAD, cardiomyopathy, or a heart defect.

Additional References:

Your Care with Me

If you need to talk with me after your visit or procedure, please call my office. You can also e-mail me with nonurgent issues from this website whenever it is convenient for you.

If you have urgent concerns or issues while my office is closed, or need general medical advice, you can call the Appointment and Advice line, available 24 hours a day, 7 days a week. You will be connected with a nurse who can give you immediate advice.

For general medical advice, our Appointment and Advice line is available 24 hours a day, 7 days a week.

If you have more immediate concerns or issues while my office is closed, you can call the Appointment and Advice line. You will be connected with a nurse who can give you immediate advice.

Coordinating Your Care

Having all of our Kaiser Permanente departments located together or nearby, including pharmacy, laboratory, radiology, and health education, makes getting your care easier for you.

Another major benefit is our comprehensive electronic medical record system, which allows all of the doctors and clinicians involved in your care to stay connected on your health status and collaborate with each other as appropriate.

When every member of the health care team is aware of all aspects of your condition, care is safer and more effective.

If you come to an office visit
  • At the beginning of your visit, you will receive information about when you are due for your next test, screening, or immunization. We can discuss and schedule any preventive tests that you need. 
  • At the end of your visit, you may receive a document called the “After Visit Summary” that will summarize the issues we discussed during your visit. You can refer to it if you forget what we discussed, or if you just want to recheck your vital signs and weight. You can also view it online under Past Visits.
  • To help you prepare for your visit, please see additional details under Office Visit. 
If I prescribe medications

We will work together to monitor and assess how your medications are working and make adjustments over time. Prescriptions can be filled at any Kaiser Permanente pharmacy. Just let me know which pharmacy works best for you, and I will send the prescription electronically in advance of your arrival at the pharmacy.

If refills are needed in the future, you can:

  • Order them online or by phone. Order future refills from my home page or by phone using the pharmacy refill number on your prescription label.
  • Have them delivered to you by mail at no extra cost. Or you can pick up your medications at the pharmacy. If no refills remain when you place your order, the pharmacy will contact me regarding your prescription.
If lab testing or imaging is needed

For lab tests, I will use our electronic medical record system to send the requisition to the Kaiser Permanente laboratory of your choice. For imaging procedures, we will schedule an appointment with the Radiology department. When the results are ready, I will contact you with your results by letter, secure e-mail message, or phone. In addition, you can view most of your laboratory results online, along with any comments that I have attached to explain them.

If I refer you to another specialty colleague

If we decide together that your condition would also benefit from the care of other types of specialists, our staff will help arrange the appointment(s) with one or more of my specialty colleagues.

If Surgery or a Procedure Is a Treatment Option

I will recommend that you review educational information and tools to help you prepare for your procedure or surgery. The information will often help you decide whether surgery is right for you. If you decide to have a surgery or procedure, the information will provide details about how to prepare and what to expect.

If we proceed with surgery, I will have my Surgery Scheduler contact you to determine a surgery date and provide you with additional instructions regarding your procedure. Once your surgery is scheduled, a medical colleague of mine will contact you to conduct a preoperative medical evaluation that will assure that you are properly prepared for your surgery.

If you are considering surgery or a procedure or want more information about your heart problem, please review our health tool called “Preparing for Your Procedure” (Emmi). Emmi programs are available for the following cardiology topics:

  • Anesthesia for an Adult
  • Angiogram with Possible Angioplasty
  • Atrial Fibrillation Overview
  • Aortic Valve Replacement
  • Cardiac Catheter Ablation (SVT)
  • Cardiac Catheter Ablation (VT)
  • Cardiac Pacemaker
  • Coronary Artery Bypass Surgery (CABG)
  • Defib (Cardiac Resynchronization Therapy Defibrillator)
  • Defib (Implantable Cardioverter Defibrillator)
  • Mitral Valve Repair or Replacement
  • Taking Warfarin (Coumadin®)

Convenient Resources for You

As your specialist, I have a goal to provide high-quality care and to offer you choices that make your health care convenient. I recommend that you become familiar with the many resources we offer so that you can choose the services that work best for you.

My Doctor Online is available at any time that is most convenient for you. From my home page you can:

Manage your care securely
  • View and compose secure e-mail messages.
  • Manage your prescriptions.
  • View your past visits and test results.
  • View your preventive services to see whether you are due for a routine screening or updated immunization.
Learn more about your condition
  • Read about causes, symptoms, treatments, and procedures.
  • Find interactive health tools, videos, and podcasts to help you manage your condition.
  • View programs to help you decide on or prepare for a surgery or procedure.
Stay healthy
  • Locate health education classes and support groups offered at every medical center.
  • Explore interactive programs, videos, and podcasts that focus on helping you stay healthy.
  • View your Preventive Services to see whether you are due for a routine screening or updated immunization.

Related Health Tools:


See more Health Tools »

If you have an emergency medical condition, call 911 or go to the nearest hospital. An emergency medical condition is any of the following: (1) a medical condition that manifests itself by acute symptoms of sufficient severity (including severe pain) such that you could reasonably expect the absence of immediate medical attention to result in serious jeopardy to your health or body functions or organs; (2) active labor when there isn't enough time for safe transfer to a Plan hospital (or designated hospital) before delivery, or if transfer poses a threat to your (or your unborn child's) health and safety, or (3) a mental disorder that manifests itself by acute symptoms of sufficient severity such that either you are an immediate danger to yourself or others, or you are not immediately able to provide for, or use, food, shelter, or clothing, due to the mental disorder.

This information is not intended to diagnose health problems or to take the place of specific medical advice or care you receive from your physician or other health care professional. If you have persistent health problems, or if you have additional questions, please consult with your doctor. If you have questions or need more information about your medication, please speak to your pharmacist. Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.

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