Bioprinting A New Heart

Bioprinting A New Heart

Capital Cardiology Associates

Building a New Heart

Researchers are getting closer to a 3D printed heart

Animation: BIOLIFE4D

Scientists can 3D print human heart tissue now. Biolife4D, a Chicago-based company, announced the breakthrough at the end of June. The company is opening a new facility in Houston to print a human cardiac patch, containing multiple cell types which make up the human heart. It could one day be used to help treat patients who have suffered acute heart failure in order to restore lost myocardial contractility, the ability of the heart to generate force for pumping blood around the body. If this sounds amazing, press play to watch the video from BioLife4D that explains how this works.

“It’s amazing how quickly things are moving in this area of technology,” remarked Dr. Robert Benton, Director of Clinical Research at Capital Cardiology Associates. BioLife4D’s advancement showcases the promise of 3D printing in the healthcare field. The ultimate goal is to able to print whole, complex organs for transplants. That work is still decades away. The work that is being accomplished now is encouraging doctors that 3D printing can help save and improve patient’s lives in ways that, until this technology was possible, seemed like an idea from science fiction.

How 3D Printing Works

3D printers use a digital file of an object, like a child’s toy, and turn the whole object into thousands of tiny slices or layers that are printed from the bottom-up, slice by slice. It would be like baking a loaf of bread by the slice, then gluing them together. You can purchase a 3D printer for your home for around $100. All you need is a computer, printer, and design program. You could design, press “print”, go to bed and wake up the next morning with that child’s toy completed.

In the medicine, 3D printers are much more complex and are used in more advanced applications than a home printer, but the basic concept is about the same.

Building Biological Replacements

A 3-D print of an artificial heart valve
Image: Jonathan T. Butcher, Cornell University

Professor Jonathan T. Butcher and his research team at Cornell University have been working on “bio printing” technology to create precise, 3-D structures from living tissue. Using computer design programs, his team has been trying to map the precise geometric pattern that matches the heart valve dimensions. His team has been closely studying the very thin valve tissue that keeps blood flowing in one direction.

Their goal is to create artificial heart valves that can be used as replacements for patients with aortic valve stenosis. In a normal heart (aortic) valve, blood flows in one direction – from the left ventricle to the body. A healthy valve snaps shut to prevent blood from flowing from the body back into the heart. In a heart with AVS, birth abnormalities or the valve opening is too small, which prevent the heart valve from closing properly. This allows blood from the body to flow back into the heart, putting stress back on the heart. Treatment options include surgical and nonsurgical methods.

Professor Butcher’s team has created a printed heart valve that will soon be tested in sheep. Their challenge is to build a heart valve that not only simulates the heart’s natural blood flow pulses but also has the ability to “grow” or be a “living” valve that can handle the workload of a young or active person. This objective goes far beyond the science used in current prosthetic or replacement valve options.

Dr. Benton is excited about the advancement of heart bioprinting technology. After a heart attack, unlike the brain and lungs, the heart cannot heal itself. “Unfortunately once a heart muscle dies in a heart attack, it’s not coming back,” noted Benton. “We have medicines that help the rest of the heart work more efficiently. There are reasonable things we can do if you have had a heart attack to prevent the heart muscle from remodeling and becoming inefficient. But there is a point where we need these smart guys in technology to come up with a game changer for us.”

For the research team at Cornell University and companies like Biolife4D, preclinical testing and research in synthetic replacements rely on the talent of today’s scientist and the limit of current technology. The biomedical community looks to the future, working in the moment on advancements that will take years to develop. For heart patients today, Dr. Benton points to the benefits they have over previous generations. “Currently we can do an awful lot for patients, there’s no doubt about it. We don’t have those ‘magic medicines’ yet. I can’t tell you if 100 years from now you will take a pill and get a new heart. I do see the next level will be these new technologies that fuse your heart muscles back together, or stem cell muscles, to repair or renew damage or defective parts of your heart.”

Written by: Michael Arce, Media Specialist
Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a healthcare professional.

Gut Bacteria and Your Heart Health

Gut Bacteria and Your Heart Health

Capital Cardiology Associates

Gut Bacteria and Your Heart Health

How trillions of bacteria in your gut impact your cardiovascular health

Inside your body right now are about 300 to 500 different types of gut bacteria. Most live in your intestines and colon, helping with your digestive functions. But there are a quite a few of these microbes that do much more than breakdown food. Gut bacteria plays a role in your immune function, weight gain, thyroid function, and brain health. An innovative study found a link between our heart health and the health of our gut, highlighting the importance of physical exercise, a heart healthy diet, and limiting antibiotics for keeping both at optimal levels. Researchers from the Cleveland Clinic in Ohio are focusing on one of the trillions of “good” bacteria called atrimethylamine N-oxide (TMAO), which gut bacteria produce. Their goal: to better understand how these bacteria are helpful in our body. Previous studies on this gut bacteria chemical have been powerful indicators of a patient’s risk of future cardiovascular disease, heart attack, or stroke.

Think of your body as your own solar system with all of your major organs servings as planets. Your heart for example would be Earth, the sun your brain. If you looked at your blood stream as the night sky, the trillions of stars would be the nutrients, oxygen, and bacteria that travel in your blood. Your vascular system is what fuels and provides life to the rest of your body. “This is something that we have missed out on so many aspects of medical care, cardiology is one of them, your heart and your vascular system,” states Dr. Robert Benton, Director of Clinical Research at Capital Cardiology Associates. “There is so much evidence that the gut bacteria, the flora, that we live with, we think they are a pest in our stomach but we need that flora in our gut.”

There are around 40 trillion bacteria in your body, most of which are in your intestines. Collectively, they are known as your gut microbiota, and they are hugely important for your health. Dr. Benton expanded on their role, “gut bacteria helps process certain chemicals, just as they provide us with certain chemicals. Just like a tree that grows has bacteria in its roots, the bacteria will supply the tree with minerals and the tree supplies the bacteria with sugars, this same thing occurs in our gut.” Gut bacteria in your digestive system has the capability of affecting your body’s vitamin and mineral absorbency, hormone regulation, digestion, vitamin production, immune response, and ability to eliminate toxins, not to mention your overall mental health.

The research team at the Cleveland Clinic worked on a drug therapy that lowered clot formations following an arterial injury that did not kill gut bacteria. The science is difficult, targeting specific parts of the gut bacteria without damaging the “good” microbes. Dr. Benton commented on the importance of this research. “You’re going to find this to be a rage of important information over the next few years in so many specialties. You can find evidence that change in the gut flora can lead to depression because of the changing of the active chemicals that are processed by the gut bacteria. There are so many different places in and on your body where this is important.”

One concern from the onset with the research team was avoiding antibiotics that indiscriminately destroy potentially useful gut bacteria. “I think people are aware that these antibiotics don’t just go attack the bad bacteria that cause the problem, but they attack ALL of the bacteria in your body,” noted Dr. Benton. “We should not be just handing out antibiotics to the average person with a common cold or cough. We need to allow those healthier bodies time to mount an immune response to fight simple, bad bacteria infections on their own. Many illnesses are caused by viruses which antibiotics don’t act against anyway. Especially children. Parents want to bring their kids to the pediatrician and expect antibiotics all of the time. I think it’s not necessary, and I think you might be hurting yourself. You’re changing the entire flora that is affecting the herd of humans. We now have these very dangerous ‘superbugs’ in the hospital. They are resistant to multiple antibiotics. These superbugs act like the king of the hospital, in that, they do so much damage to hospitals but in reality they are really weaklings when you get them out in the community. If we get your flora up, your body can overwhelm these ‘superbugs’.”

A Healthy Diet Helps

The best way to maintain healthy gut bacteria is to eat a range of fresh, whole foods, mainly from plant sources like fruits, veggies, legumes, beans and whole grains. The problem is, the average American diet is loaded with processed sugars, fatty foods, and preservatives (chemicals) that all upset bacteria levels. “What I do tell patients is, and I think this is very important, is to eat foods that are as unprocessed as possible,” advises Dr. Benton. “When you get to the point of eating whole grain foods, ingredients that have not been through the chemical factory. I joke with patients that there are certain types of margarine where one molecule is from plastic. That can’t be good for you, right?”

Written by: Michael Arce, Media Specialist
Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a healthcare professional.

Broken Heart Syndrome

Broken Heart Syndrome

PATIENT EDUCATION

The Truth About Broken Heart Syndrome

The ties that unite mental health, depression, and heart disease

Women between the ages of 58 and 75 are at a greater risk of this reversible heart condition.

A new study published by the American Medical Association, shows the many ways in which depression negatively affects your health and highlights the benefits of exercise for relieving depression and keeping your heart healthy. The research team found that participants with high fitness levels at midlife had a 56 percent lower risk of dying from heart disease after receiving a diagnosis of depression.
This study caught the attention of Capital Cardiology Associates board-certified cardiologist, Dr. Brion Winston, who routinely prescribes fitness and physical activity to his patients. “Many of my patients have overt heart or vascular disease; they’ve had a heart attack, blocked arteries, or maybe a mini-stroke. Now we are looking to promote wellness.” Our discussion began to focus on how activity and exercise, as simple as taking a walk around the neighborhood after facing a stressful situation, helps clear our mind and raise our spirits. For cardiac patients or older adults with heart conditions, stress can be a trigger that elevates their risk factor for angina (chest pain) and shortness of breath.
Dr. Winston shared, “there is a particular syndrome that we look at in cardiology, we call it commonly a ‘broken heart syndrome.’ This is due to an acute stressful event and sometimes this precipitated by very bad news.” While this term may seem more like an old wives’ tale, a spouse who passes away close after the sudden or untimely death of their partner; takotsubo cardiomyopathy as it’s known in the medical community, is very real. “Tako-subo” is Japanese for “fishing pot for trapping octopus.” Since the condition was first reported in Japan in 1990, the name fits how the left ventricle of the heart changes into a smilier shape as the pot.
Takotsubo with captured octopus
Figure A shows a normal heart. Figure B shows a heart with takotsubo cardiomyopathy.
Since the Japanese study, there have been a few recently famous celebrity cases reported. The latest was in 2016 when actress Debbie Reynolds passed away at the age of 84, just a day after the death of her daughter Carrie Fisher. Oddly enough, both actresses suffered cardiac episodes: Carrie died of a heart attack, Debbie from a fatal stroke. Her son Todd Fisher revealed to the media that her last words were, “I miss her so much, I want to be with Carrie.”
“This a well described syndrome that any cardiologist has seen,” noted Dr. Winston. “I will make this diagnosis about once a month in the cardiac catheterization lab where someone comes a symptom suggesting a heart attack, an EKG shows changes in their heart pattern which would suggest a heart attack, but then when I look at their arteries with a coronary angiography, their arteries are normal, maybe only mildly irregular. These patients would also have a certain pattern to the squeezing function of their heart which would suggests this broken heart syndrome. After evaluation, we can rule out a heart attack and I can gain some further history from the patient, I’ll ask them, ‘has anything stressful happened in your life recently?’ Then it will sometimes come to light that, yes, they had witnessed a horrible car accident, gone through divorce, heard some bad news, or learned that child or spouse has an illness.”
Broken heart syndrome is different from a heart attack, in that heart attacks are generally caused by complete or partial blockage of plaque in an artery of the heart. That artery build up of fatty acids narrows the blood flow, causing a blood clot in the wall of the artery. A heart attack is then the result of the buildup when the heart muscle is deprived of oxygen and nutrients. In broken heart syndrome, the arteries are not blocked, although because of other factors caused by stress, the blood flow is reduced to the heart.
Broken heart syndrome researcher indicates that women, above the age of 50 along with people who have neurological disorders (like a head injury or epilepsy), anxiety or depression are at a great risk of broken heart syndrome. Researchers suspect that older women are more vulnerable because of reduced levels of estrogen after menopause. “The treatments for broken heart syndrome include some of the treatments we have for other heart disease, people can often become quite sick,” adds Winston. “They sometimes can require medication.”
In rare cases, broken heart syndrome is fatal. “Rarely, when they are hospitalized, this can progress to a full on shock syndrome with ICU admission or need for intensive care,” noted Dr. Winston. Doctors can prescribe mediations that can block the effect of stress hormones on the heart. In most cases, the condition usually reverses itself in days or weeks. Or, as the research would suggest, a long walk with a friend to put what stresses you, behind you.
Written by: Michael Arce, Media Specialist
Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a healthcare professional.

National Atrial Fibrillation Awareness Month

National Atrial Fibrillation Awareness Month

HEART HEALTH

Atrial Fibrillation: What You Need

To Know About The Most Common

Heart Rhythm Disorder

September is National Atrial Fibrillation Awareness Month. Know the symptoms to reduce your risk of stroke.

September is National Atrial Fibrillation Awareness Month. If you’re like most Americans, you have no idea what atrial fibrillation is or how to identify it. A 2014 survey showed that fewer than 20% of people could, “correctly identify medical conditions such as sleep apnea and diabetes as risk factors for atrial fibrillation.” The average person with atrial fibrillation, or AFib, is 5 times more likely to suffer a stroke than someone with a regular heartbeat. This month, Capital Cardiology Associates strives to educate the Capital Region on the most common type of heartbeat abnormality that affects more than 3 million people in the United States: atrial fibrillation.

What is Atrial Fibrillation (AFib)

“Atrial fibrillation is the most common abnormality that we experience in cardiology,” says Dr. Lance Sullenberger, board certified cardiologist at Capital Cardiology Associates. The American College of Cardiology describes AFib as, “the most common heart rhythm disorder (arrhythmia).” AFib is an irregular heartbeat that breaks down into two main types:

• Valvular AFib refers to atrial fibrillation that is caused by a heart valve problem. Examples of a heart valve problem include a narrow or leaking valve, or a valve repair or replacement.

• Non-valvular AFib (sometimes called NVAF) refers to atrial fibrillation that is not caused by a heart valve problem. Non-valvular atrial fibrillation is the most common type of AFib.

While treatment options may be different for non-valvular and valvular atrial fibrillation, the effects of the disease are often the same. AFib sets off a chain reaction: your heart isn’t beating normally which causes your blood to stop moving or flowing well, increasing your risk of heart failure. Because blood isn’t pumped out of the heart normally, it’s easier for blood cells to stick together and form clots which can increase the risk of heart failure, heart attack, or stroke if they travel to another part of your body and cut off blood supply to the brain.

AFib has several causes: heart disease, high blood pressure, heart defects from birth, sleep apnea, certain medicines, heavy alcohol or caffeine consumption, drug use and smoking. If you have a family history of heart disease, heart attack, or stroke you are at a greater risk of atrial fibrillation.

AFib Diagnosis

Dr. Sullenberger explains AFib as, “when the top chambers of the heart go electrically haywire. They are firing a bunch of electrical signals to the bottom chamber which controls the pulse. The bottom chambers then start beating irregularly.” To investigate your heart’s electrical activity, your doctor will order a series of cardiac tests. The first would be an electrocardiogram (ECG). “It is a simple ‘first step’ tool to help your doctor increase or decrease his or her suspicion that your symptom is or is not related to your heart,” says Sullenberger. During an ECG electrodes are placed on your chest, arms, and legs to detect the electrical waves your heart makes. It usually takes about five to ten minutes to complete the test.

There are some special medical diagnostic devices that your doctor may have you wear to record your heart activity. “A Holter Monitor is an external unit that is worn for 24 to 48 hours,” shares Maryellen King, Advanced Practice Nurse at Capital Cardiology Associates. “While you are wearing it, the device records heart rhythm data. If there are changes in the rhythm we will see it. It’s a way for us to identify patterns that wouldn’t show up on ‘snapshot’ EKG that we would take in the office. It’s the first step in longer cardiac monitoring that we use.”
The Mayo Clinic reports that more than 200,000 AFib cases are diagnosed per year in the United States. Typically at the age of 65, adults are at a greater risk of abnormal heart rhythms, although many AFib cases are being diagnosed younger in life, some as young as 40 years old. Dr. Sullenberger pointed out that, “the problem with atrial fibrillation, not only is that it can cause symptoms, it is a major risk factor for stroke within the United States. When we see a patient with AFib, we have to make a determination whether that patient’s risk of stroke merits them being on blood thinner medications, some of which you see advertised on TV.”

AFib is a major health problem,
in that, it also makes blood clots
in the heart that can travel and
can cause a stroke or block flow
to other critical organs.

 

AFib Symptoms

The most common symptom of AFib is an irregular heartbeat or palpitations. Dr. Sullenberger describes a thumping or racing heart, some patients experience fluttering or feeling like their heart is skipping a beat. Other common symptoms are shortness of breath, dizziness or light-headedness, and fatigue. If you experience these symptoms, contact your doctor immediately. “Every day I see patients who have heart palpitations,” notes Sullenberger. “What we are really trying to determine when we see a patient with palpitation is: do they have atrial fibrillation?”

Sometimes AFib doesn’t present or cause any symptoms. This is why September has been designated as National Atrial Fibrillation Awareness Month. Heart disease is often looked as a condition that happens to older adults or seniors. This is not the case. A 2015 study published in the European Heart Journal illustrates how atrial fibrillation progresses over time. The study noted that Larry Bird, Tony Blair, and Mother Teresa all suffered from atrial fibrillation. In adults under the age of 50, certain lifestyle factors such as alcohol consumption and smoking can trigger an AFib episode in addition to hypertension, hyperthyroidism, or valvular heart disease.

AFib Treatment

The good news is that with proper treatment, you can live a full life with AFib. There are different treatment options that depend on your age, symptoms, and frequency of episodes, whether your heart rate is under control, your risk of stroke, other medical conditions (for example, if you already have heart disease). Your doctor will prescribe your treatment that will focus on lifestyle changes and therapies to prevent blood clots, heart failure, and stroke.

Lifestyle changes will
most likely include:

• If you smoke, quitting
• Getting regular physical
activity and exercise
• Eating a heart healthy diet
(like the Mediterranean Diet)
that is low in fat and salt
• Maintaining a healthy weight
with regular doctor check-ups

Your doctor also has some medication options. You could be prescribed a blood thinner/anticoagulant that you have seen in advertising. The blood thinner warfarin (also known as Coumadin®) has been around for more than 60 years. There are also several newer blood thinners available now, including Eliquis® (apixaban), Pradaxa® (dabigatran), Xarelto® (rivaroxaban), and Savaysa® (edoxaban).

AFib Procedures

For some patients, implants could be an alternative to the lifelong use of blood thinners. Some people with atrial fibrillation who should take warfarin or another anticoagulant to reduce their stroke risk can’t due to their lifestyle or health history. Other AFib patients choose not to take anticoagulants, or blood thinners, due to side effects or for other reasons. Like warfarin, a common blood thinner, WATCHMAN can effectively reduce stroke risk. This permanent implant is for people with AFib not caused by a heart valve problem who need an alternative to warfarin, or a warfarin substitute.

Left atrial appendage closure: A procedure called left atrial appendage closure provides an alternative to warfarin for people who need one. The left atrial appendage is a small pouch at the top of the heart. When a blood clot escapes from the left atrial appendage and travels to another part of the body, it can cut off the blood supply to the brain, causing a stroke. In people with AFib not caused by a heart valve problem, more than 90% of stroke-causing clots that come from the heart are formed in the left atrial appendage (LAA). Closing off the LAA is an effective way to reduce stroke risk in these people.
Every person with atrial fibrillation has different needs. If you’ve been diagnosed with AFib, talk to your doctor about the AFib treatment options available to you. Your doctor will help you understand the risks and benefits associated with each option. Together you can choose the treatment that is right for you.

September is National Atrial Fibrillation Awareness Month. If you have a family history of heart disease or have questions about your risk of heart disease, stroke, or heart attack — talk with your doctor. “The first person to talk with is your primary care physician,” points out Sullenberger. “Address what your concerns are. You are much better off finding things that can be changed before they become life-altering than having that problem develop into an emergency room visit or hospital stay that could have been prevented.”

Written by Michael Arce, Marketing Coordinator, Capital Cardiology Associates
Any medical information published on this website is not intended as a substitute for informed medical advice, and you should not take any action before consulting with a healthcare professional.

Cardiac Testing

Cardiac Testing

Capital Cardiology Associates

Cardiac Testing

The Confusing

Potpourri of

Cardiac Testing

You make an appointment to see your Primary Care Physician (PCP) for a feeling of mild pressure in your chest which you have noticed recently. Your doctor performs an electrocardiogram (ECG) which you are told is normal, but she still wants you to have more testing. Your question is: “Do I need to be worried?” When it comes to testing for heart disease, there seems to be an endless array of heart tests to which a patient with symptoms can be subjected. In this article, we will address testing for patients WITH symptoms and how these tests differ from one another.

Primary Care Physicians, Primary Care Providers, and cardiologists frequently encounter patients with symptoms which may be related to their heart. These symptoms include chest pain, chest pressure, shortness of breath, left arm pain or numbness, jaw pain, and upper back pain. When confronted with such symptoms, the medical provider’s number one priority is to make sure the symptom is not a signal of underlying heart disease; more specifically, of plaque (composed of cholesterol and inflammatory cells) clogging the blood vessels that carry oxygenated blood to the heart muscle. Heart related symptoms usually occur only when such a blood vessel is more than 60-70% “clogged.”

The first step your doctor usually performs is an ECG, which is a simple evaluation of the heart structure and function based on the electrical activity of the heart picked up by 12 sticker “leads” placed on the skin. It is indeed a rather “crude” screening test: an ECG which is abnormal does not necessarily signify a problem with the heart, nor does a normal ECG eliminate the possibility of a heart problem. Nevertheless, it is simple to perform and a “first-step” tool to help your doctor increase or decrease his or her suspicion that your symptom is or is not related to your heart.

At the other end of the spectrum, the most definitive test for clogged arteries is a cardiac catheterization. In this procedure, dye is injected into the arteries of the heart via a small tube inserted through an artery in the groin or wrist. This is the definitive, or “gold standard”, procedure for determining if a patient’s symptom is indeed caused by a blockage in a heart artery. However, this test is invasive and therefore carries the risk associated with invasive procedure and the dye used in the test can cause kidney problems for patients who are at risk for kidney disease. Moreover, in New York State, it must be performed in the hospital, and thus it is inconvenient and expensive. For these reasons, cardiac catheterization is reserved for patients whose symptoms and medical history make it highly likely that they have a blocked artery.

That brings us to the array of tests which fall between the simple ECG and the invasive cardiac catheterization. As a cardiologist, I divide the remaining tests into two major categories: tests designed to give information on the presence of abnormal blood flow to the heart muscle, and tests designed to display the arteries of the heart themselves in order to reveal the presence or absence of “clogging”.

Testing used to examine for abnormal blood flow to the heart muscle involves some form of stress testing. The most basic of these tests is a “regular” exercise stress test in which a patient is placed on a treadmill while attached to an ECG machine. The treadmill increases in speed and incline every 3 minutes, and evidence of lack of blood flow (presumably from a blocked artery) is suspected based on changes in the ECG during exercise or development of symptoms during exercise. The benefit of this type of test is that it is fairly simple to perform; however, it does require that a patient be able to exercise and that his or her ECG is normal prior to the test.

A more sensitive and specific way to perform stress testing is to combine the stress test with pictures of the heart. One way to obtain these pictures is to use ultrasound immediately after the stress test in order to assess the movement of the heart (abnormal movement is indicative of a blockage in an artery). This type of testing is known as a “Stress Echocardiogram”; its benefits are that it is easy to perform, adds important information to a stress test, and does not involve any radiation. The drawback, however, is that it still requires that a patient to be able to exercise. It also does not perform well with heavier patients where the extra weight interferes with the ability to obtain good images of the heart using ultrasound.

The second type of stress testing in which pictures are taken to assess for blood flow is nuclear stress testing. In a nuclear stress test, a patient performs an exercise stress test, but at the peak of the exercise, the patient is injected with a tiny amount of radioactive “dye”. This dye then flows to the heart muscle through the arteries supplying the heart with blood. Pictures of the heart are then obtained showing where and how much of the dye has made it to the heart muscle. Areas where there is little or no radioactivity can be assumed to be supplied by a blood vessel which is clogged.

Nuclear stress tests can also be performed WITHOUT exercise by using a medication to “stress” the patient. (An important misconception made by patients is that the “stress medication” is actually stressing the body in the way that exercise does with increased heart rate and blood pressure. In reality, these medications just cause dilatation of the blood vessels of the heart and are not truly a “stress” on the body, yet the accuracy of the test is the same as if the patient had exercised.) The benefits of nuclear stress testing are both that it adds important information to stress tests and also that it is easy to perform in patients who cannot exercise. The drawbacks are that it does involve a small dose of radiation and it takes several hours of time to complete the test.

A more advanced form of nuclear stress testing is called a Positron Emission Test (PET) scan. In a PET scan, the patient is given a medication to “stress” them and a different type of radioactive “dye” is used to assess blood flow. PET scans use LESS radiation than traditional nuclear stress tests but create better images due to the type of radioactive dye and camera utilized. A PET scan is rather fast and the test usually takes less than 1 hour to complete. The PET scan performs particularly well with obese patients because of the quality of the images from the advanced camera and type of radioactive dye. The drawback of PET scans is that they are more expensive than a traditional nuclear stress test and do involve radiation (though less than traditional nuclear stress testing).

The other type of test used to evaluate for blockage is a test which looks at the arteries themselves to directly assess the degree of blockage. The “gold standard” cardiac catheterization does this, but so does a non-invasive, advanced CT scan known as a Coronary CT Angiogram (Coronary CTA). In this type of test, dye is injected through an IV during a CT scan to display the arteries and degree of blockage. This type of test is best suited for a patient who has symptoms which could potentially be cardiac in origin, but the suspicion for actual coronary disease as a cause of the symptoms is still low. The benefits of the CT angiogram are that it is fast, easy to perform, does not involve any exercise, and displays if there is ANY coronary artery disease (not just if there are “clogged” arteries as stress tests do). The drawbacks are that it does involve use of CT scan dye (which can injure the kidneys in patients with abnormal kidney function) and it also involves a small dose of radiation.

In the end, there are a multitude of different tests which can be ordered by your doctor to determine if your symptoms are truly due to a blocked artery in the heart. From a patient perspective, the nuances of the tests can be confusing and each type of test has both positive and negative aspects. The role of your doctor is to choose the “right test for the right patient”, which is the test which helps answer the question: “Do I need to be worried?”

Written by: Dr. Lance E. Sullenberger, Co-Medical Director of the Cardiovascular CT Scanning Suite at Capital Cardiology Associates

Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a healthcare professional.