FAQ Noninvasive Cardiovascular Diagnostic Testing
What is meant by “noninvasive cardiovascular testing”?
Noninvasive testing refers to testing of the heart without procedures that involve surgery or other methods that directly touch the heart and blood vessels. It is a way to provide information about your heart and blood vessels from the outside and therefore without risk of injury of the heart and blood vessels. Some examples are stress testing, EKGs, and ultrasound testing. Usually the first step of diagnosis uses noninvasive testing. Sometimes, it is necessary to do invasive testing and procedures on the heart that involve directly touching the heart with surgical instruments, and we will help you determine when this is necessary.
What kind of heart and vascular disease can you pick up with you diagnostic tests?
We evaluate a wide range of heart and circulation diseases including coronary artery disease (blocked arteries of the heart), valve disorders, heart failure (a weakened heart muscle), and disease of the arteries and veins of the body. The vast majority of these disorders are first diagnosed with painless, safe diagnostic tests like ultrasound.
I feel fine! Why do I need testing for my heart?
Unfortunately, heart disease is the number one killer of our population, so many people are at risk. Even more unfortunately, about 50% of people who die of a heart attack had no preceding symptoms and “felt fine” in the weeks prior to their death if their friends and family were asked. Therefore, we are very aggressive in our testing to attempt to pick up evidence of heart disease especially in this population of patients that “feel fine” and have undiagnosed heart disease.
I have chest pain. Is this dangerous?
Anyone complaining of chest pain deserves a consultation at our Center. Your chest pain may turn out to be nothing dangerous, but it may also signify that you have serious heart disease. We help you figure out whether your chest pain is dangerous based on a comprehensive history, physical and laboratory testing to make up your cardiac risk profile. You should never ignore chest pain or any other sign and symptom that could be related to heart disease.
Do I have to have chest pain to have heart disease?
Definitely not! Most patients, especially certain groups of patients such as women and patients with diabetes, do not present with typical chest pain symptoms. Your symptoms may be much more subtle but still signify heart disease. With our comprehensive evaluation we will help put together if your symptoms signify heart disease whether you have typical chest pain or not.
I heard there is “bad” and “good” cholesterol. What does this mean?
There are certain types of cholesterol in your blood that put you at risk for coronary artery disease (CAD) because they lead to cholesterol deposits in the blood vessels. This is the so-called “bad”cholesterol. LDL cholesterol is an example of this. There are also other types of cholesterol that are called “good cholesterol” that do not lead to deposits in the arteries but instead are picked up by the liver and eliminated. An example of “good” cholesterol is HDL cholesterol. In general it is good to have high levels of “good” cholesterol and low levels of “bad” cholesterol.
How can you test me for diabetes and follow my diabetes once I have been diagnosed?
We use a variety of tests, but you may hear a lot about the “hemoglobin A1c test.” This is an important test we do regularly to diagnose and follow the course of your diabetes. It is important because unlike just checking the blood sugar, which can be affected by time of day and when you have last eaten a meal, the A1c test expresses your average blood sugar level throughout the past 3 months, regardless of what you ate or what time it is on the day of the test. It is also used to follow the effect of your diet and lifestyle changes, as well as you medications, on controlling your blood sugar levels.
I have shortness of breath. Does this mean I have heart disease?
Shortness of breath is one of the most common symptoms of heart disease. It also has many many other causes. This is why it is important to discuss your shortness of breath with us. At the center we will help find out whether your shortness of breath is due to heart disease through our questioning, physical exam and laboratory testing.
What is an echocardiogram? How is this different from an electrocardiogram (EKG)?
An echocardiogram is a painless, safe ultrasound test that looks at the chambers of the heart and at the valves and makes measurements of the blood flow as well as the size of the chambers and the pressures inside the chambers. An EKG on the other hand is a simple test monitoring the heart rhythm electrical activity using electrodes placed on the chest and wires connected to a monitor that record your heart’s rhythm.
I am concerned about radiation exposure from tests like the nuclear stress test. How dangerous is it to be exposed to this radiation?
We advise being exposed to the least amount of radiation as possible, because high levels of radiation can cause cancer. However, some tests are of great importance and the risk from radiation exposure is justified because the benefit of proper treatment of heart disease and prevention of heart attacks is so much greater. A nuclear stress test is an example of benefit being much greater than risk. We are all exposed to radiation throughout our daily life – from the sun, from materials inside our house, from air travel, from foods, just to name a few sources. Although it has NEVER been proven, I can estimate that the risk of developing cancer from a nuclear stress test is extremely small and similar to exposure we get from our daily life activities, on the order of 0.01% (or 1 in 10,000). On the other hand, if we are recommending this test, your risk for a heart attack or other severe heart disease is at LEAST 10%, and may be as high as 90%, so the benefit of diagnosing heart disease greatly outweighs any risk!
I am still concerned about radiation exposure. Are there any alternatives to typical nuclear stress test examinations that don’t involve radiation?
Yes. However, one of the reasons we recommend a nuclear stress test for you is that based on your individual risk profile, less detailed or simpler tests that don’t involve radiation, such as ultrasound tests, may not be adequate to make your diagnosis. This is dangerous because we may end up missing significant heart disease by using less accurate tests. Usually, non-radiation based stress testing is useful for patients who are either very young or have very few risk factors for heart disease, but becomes very inaccurate once you get older or accumulate more risk factors for heart disease.
Is there anything you do to help minimize radiation exposure during your tests?
Definitely. We use only the doses necessary for the test to be performed, which is often based on your body weight. We also follow the latest technology and the examinations we offer use materials that expose you to far less radiation than in older versions of the test. For example, you may have heard nuclear stress tests be called “thallium stress tests” for example. This is an older radioactive tracer that is still being used by some facilities. We do not use this material anymore due to its long-lasting effects in the body and therefore higher radiation dose. The technetium-based stress tests (also known as SPECT tests) expose you to less radiation primarily because the material is cleared from the body much more quickly than older materials. Furthermore, when possible, we also offer myocardial PET imaging as an alternative to traditional nuclear stress testing, which is associated with even less radiation exposure than any of the other methods.
I have heard you talking about a SPECT stress test and a PET stress test. What is the difference?
SPECT stress testing refers to an older method of nuclear stress test, and PET a newer method. Both tests are adequate at diagnosing coronary artery disease. However, we are excited about PET testing for two main reasons: One, it is much more accurate because it is less subject to false positives and false negatives and can pick up findings of coronary artery disease at a much earlier stage than SPECT testing, which may help us diagnose and start treatment of your heart disease earlier. Two, and equally important, it offers much less radiation exposure than even the most modern versions of the SPECT test.
It seems like PET stress testing is more accurate and safer than SPECT testing. Why then do you still perform SPECT stress testing?
I believe that because of the advantages of PET testing described above (less radiation and more accuracy), eventually it will replace SPECT testing completely. Unfortunately the largest obstacle to providing everyone with PET testing is that a fair number of insurance companies still do not allow PET testing because of its higher cost and that it is a relatively new technology. However, even if you are not approved for a PET test, we are constantly improving SPECT testing to expose you to the lowest dose of radiation possible, and I do not consider SPECT to have a dangerously high level of radiation compared to a PET test.
Are there other risks to a stress test, like can it actually cause me to have a heart attack?
There are small risks to any procedure, but in the case of a stress test, it is extremely rare for it to actually trigger a heart attack, approximately 1/20,000. It is important to note that this risk is similar to the risk of simply going out to exercise, as this is very similar to what we are doing in the stress test. I believe it is far better to know whether you have treatable heart disease, and if something is going to happen to you as a result, it is better to have this happen while you are supervised by our doctors than alone in the street.