Answers to Common Questions

Tests

Learn more about medical tests: how they work, what the results mean, and how heart conditions are diagnosed.

  • What is a lipid panel?
  • A lipid panel is a blood test that measures fat and fatty substances in the blood. Typically, this panel measures cholesterol and triglycerides to identify lipid disorders that increase cardiovascular risk. Treating lipid disorders with lifestyle changes and medication, when necessary, can help significantly reduce risk for heart disease.

  • What is grip strength?
  • Grip strength is a measure of how hard a person can squeeze an object in his or her hand. Grip strength is a useful indicator of overall muscle strength. Typically, grip strength increases during adolescence and declines with old age. However, a lack of physical activity and chronic health conditions can also impact muscle strength. Doctors may use grip strength to assess overall health of patients, especially as they age.
  • What is coronary angiography?
  • Coronary angiography is a common medical test used to diagnose heart disease. During coronary angiography, a thin, flexible tube called a catheter is put into a blood vessel and threaded into the heart’s arteries. A dye is then released into the bloodstream, and X-ray pictures are taken to allow doctors see if the heart’s arteries are blocked or narrowed. For patients diagnosed with heart disease, coronary angiography can help guide treatment options such as lifestyle changes, medication and/or medical procedures.
  • What is a computed tomography coronary angiography (CT scan)?
  • A computed tomography coronary angiography, often referred to as a cardiac CT scan, uses advanced technology to provide 3-D images of the heart. These images are used to diagnose coronary artery disease by identifying blockages in the heart due to the build-up of plaque or calcium deposits on the artery walls.
  • What is ejection fraction?
  • Ejection fraction is a test used to measure the amount of blood leaving the heart each time it contracts.  Doctors typically measure ejection fraction when a patient shows signs of or is diagnosed with heart failure. Ejection fraction tells a doctor how well the heart pumps with each beat, which is used to determine the best possible treatment options to improve outcomes and quality of life.
  • Is there a safe level of radiation exposure?
  • No. Since there is no known “safe” level of radiation exposure, being exposed to radiation always carries some risk of damage to cells or tissue. However, we’re often exposed low levels of radiation in our everyday lives and in most cases, the risk of getting cancer from low doses of radiation is small.
  • Should I worry about radiation exposure from medical imaging?
  • All medical tests that use radiation carry some health risks, such as a small increased risk for cancer. It’s important to discuss both the risks and benefits associated with imaging tests with your doctor before undergoing tests that use radiation.
  • What is a cardiovascular risk estimate?
  • To identify patients at increased risk for heart disease, doctors use tools to estimate a person’s short and long-term risk of heart disease. These tools take into account factors closely related to cardiovascular risk, such as age, sex, cholesterol and smoking status, to estimate risk of developing heart disease in a given time period. Most estimates calculate short-term risk (risk of developing heart disease in the next 10 years) or long-term risk (risk of developing heart disease in an entire lifetime).
  • I am 35 and female. I am having episodes of tachycardia, up to 170 beats per minute at rest, and premature ventricular contractions (PVCs) for 3 months. I had a 24-hour Holter monitor that confirmed this. Electrocardiogram (EKG) showed ST segment depression, which I understand can be false with females. Nuclear stress test showed good perfusion and ejection fraction (EF) of 67%. I will now be going for an echocardiogram. My question is: What will an echo show that the other tests haven't shown?
  • In a patient with tachycardia, it is important to assess the left ventricular (LV) function and to rule out structural heart disease. Also the right ventricular (RV) function needs to be assessed. In addition, assessment of the heart valves is essential and can be done by echocardiogram.

    Best regards,

    Mouaz H. Al-Mallah, MD, FACC

  • I am 76 years of age. My echocardiography report shows that I have mild diastolic dysfunction. My EF is 69%. How dangerous is it? What are the risks involved?

  • The finding of mild diastolic dysfunction on an echocardiogram is not concerning. Echocardiograms, or ultrasounds of the heart, assess the left ventricular function, valvular function, and some intracardiac pressures. An ejection fraction of 69% is normal (normal is anything above 50-55%), meaning that your heart is pumping strongly. Mild diastolic dysfunction means that the heart muscle is slower to relax as it fills with blood before pumping it to the body. It is actually a common finding with age, and is considered a normal finding in patients over age 65 as there is mild increase in the stiffness of the heart muscle with age. However, this does mean that the stiffness will increase with time or cause symptoms. There is no danger or risk involved in mild diastolic dysfunction on your echocardiogram. This finding does not merit further testing or any changes to your medications. 

    Best regards,

    Michelle M. Kittleson, MD, PhD
    Director, Heart Failure Research
    Director, Post-Graduate Education in Heart Failure and Transplantation
    Cedars-Sinai Heart Institute

  • If a patient has had two negative cardiac enzyme tests and a negative electrocardiogram (EKG), what are the chances that a second EKG would be positive?

  • I assume this question addresses patients with chest pain in the emergency room. If such a patient had two negative cardiac enzyme tests and a negative EKG, the chances that a second EKG would be positive depend on many things. This is related to the patient's pre-test probability of having acute coronary syndrome or heart disease as well as how typical are his or her symptoms. Although the second EKG is unlikely to be positive if the patient has negative enzymes, a negative first EKG and no recurrence of symptoms, the chances of it being abnormal is not 0%. If the first EKG was done when the patient had no symptoms and he/she experienced recurrence of symptoms in the emergency room and an EKG is done while he or she is having chest pain, then the EKG is likely to be positive.

    Regards,

    Mouaz H. Al-Mallah, MD, MSc, FACC, FAHA, FESC

  • I am the first in my family to have had a heart attack. Since my heart attack, I have tried to learn what I could have done to have prevented it. I took the stairs, ate salads, slept, worked. When I went down there was one short warning, and that was it. This article suggests that if the patient has a family history of heart attack then an echocardiogram could be considered, but how is a person supposed to know when veins are becoming blocked? I think a test should be given, like taking your weight or height, to see how blocked a person’s veins are.
  • It’s quite common and understandable after a heart attack to wonder whether a test could have prevented it by identifying blockages in the blood vessels of the heart. However, there isn’t any test that can reliably do this just yet, for several reasons.

    The majority of heart attacks, especially in previously healthy individuals without symptoms, occur at locations where the blockage (caused by cholesterol plaques) is only mild. Unfortunately, many of the tests we have are good at identifying severe build-up of the plaques, but do not pick up mild blockages that don’t limit blood flow. The article you are referring to discusses the role of echocardiograms (an ultrasound of the heart). This test generally does not provide any information on whether there are blockages or not. One day medical science may advance to the point that we have tests to accurately predict which plaques are the most likely to lead to heart attacks. In the meantime, however, we also have to be careful about inappropriate testing, and avoid situations where the test performed doesn’t give a lot of information and can even lead to harm.

    I also want to make a final point: Although we can’t predict heart attacks perfectly, we do know that a healthy lifestyle is beneficial for reducing the risk of heart attacks as well as preventing its complications. So the things you have done, such as exercising regularly and eating healthy, are all very important and helped you get better, and I definitely encourage you to keep them up!

    Best regards,

    Siqin Ye, MD, MS

  • What is an echocardiogram?
  • An echocardiogram (also called an echo) is a type of ultrasound test that uses high-pitched sound waves that are sent through a device called a transducer. The device picks up echoes of the sound waves as they bounce off the different parts of your heart. These echoes are turned into moving pictures of your heart that can be seen on a video screen and help the doctor learn more about your heart.
  • What is a nuclear stress test?
  • Nuclear stress tests utilize imaging of the heart during physical activity and at rest to see how the heart performs in different states. Results from this imaging can help diagnose heart disease, evaluate the severity of heart conditions, and help guide treatment plans. Although nuclear stress tests are generally safe, patients undergoing these tests are exposed to radiation, which can slightly increase cancer risk.
  • What do results of a nuclear stress test show?
  • Nuclear stress tests help diagnose heart disease and provide important information that can help guide treatment plans for patients. Since imaging is taken during exercise and at rest, the test will show whether a patient has normal blood flow during exercise, at rest, or both. It can also show if there is scar tissue in the heart, like from a heart attack.
  • How is PAD diagnosed?
  • Doctors often diagnose PAD by using the ankle-brachial index (ABI) to assess blood flow to the legs. The ABI is a simple test that can be done in your doctor’s office. During the test, you lie flat while your doctor measures the blood pressure in both arms using a standard blood pressure cuff and a small hand-held Doppler ultrasound probe. The ultrasound probe detects the first sound of blood flow as the cuff is deflated; that’s the upper number in your blood pressure. Your doctor then measures the blood pressure in both ankles by placing an inflatable blood pressure cuff between the ankle and calf and again using the Doppler ultrasound probe to listen for blood flow.

    The next step is to calculate the ratio of the highest ankle pressure to the highest arm pressure on the same side of the body. This is the ankle-brachial index. If the blood pressure in the ankle is a lot lower than in the arm, it is a sign that a blockage is interfering with blood flow to the lower leg.

  • What if I have tried to learn more about my health but still have trouble understanding?
  • Patients who have trouble understanding their health conditions should ask for help from their health care team, whether it's a doctor, nurse or counselor. Health care providers can help point patients to a variety of resources that can cater to individual needs.
  • Should I have a stress test for angina?
  • Do I need a stress test to search for the cause of my cardiomyopathy?
  • Should I undergo an elective cardiac catheterization to look for blockages in my arteries?
  • How often should my doctor order tests to monitor the size of my aortic aneurysm?
  • How can I be tested for PAD?
  • How does telemedicine work?

  • Telemedicine is a modern way that patients and providers can communicate through the use of telecommunications and information technology. Although the use of telemedicine is relatively new, it can greatly improve the lines of communication between patients and their doctors and create a more effective and efficient way for patients to receive health care.
  • How are white blood cell counts tested?

  • White blood cell counts can be measured using a simple blood test, which is most commonly used to determine the presence of infections.
  • How is pre-diabetes diagnosed?

  • Pre-diabetes can be diagnosed through two types of testing: oral glucose tolerance testing and/or fasting glucose testing. Both can help identify if a patient has an impaired fasting glucose or impaired glucose tolerance.