Dr. Asad Qamar is one of the leading cardiovascular physicians in our area. He has continued to maintain a presence in OCALA MAGAZINE with informative articles regarding the treatment of atherosclerosis and cardiovascular disease, as well as erectile dysfunction and the cardiovascular implications of the condition. Last month he joined with the Marion County Dental Association and spoke directly to the link between good dental health and over all health. This month he discussed PET (Positron Emission Tomography) as one of the newest, most advanced methods for studying the heart.

“Like an X-ray, PET is painless and noninvasive,” says Dr. Asad Qamar. “It means no surgery or opening of the body is required. But unlike X-rays, PET does much more than just show a picture of the heart. PET actually gives an image of the health of the heart.”

Dr. Qamar explains that there are two reasons to have a PET scan. “The first is to check the health of the coronary arteries. They are the vessels that supply blood to the heart. If the arteries are narrowed or blocked, the heart muscle can be starved of oxygen. This is known as coronary artery disease,” he explains.

“The second is to check the heart muscle.” He points out that if heart tissue has died because of a heart attack, the heart operation is hampered and it will not work as well. He says that the doctor can use this information to plan treatment for the patient.

Dr. Qamar explains that PET myocardial perfusion imaging is invaluable for detection of hibernating myocardium. “This means that viable but oxygen starved muscles of the heart can be recruited by stinting or by pass surgery,” he says. “Similarly stunned myocardium which represents viable but shocked heart muscle can also be diagnosed by PET scanning. The strength of PET scanning compared with nuclear stress testing lies in PET’s high resolution, high radioactive counts, less attenuation artifacts, and the ability to penetrate large body habits.”

He says that certain clinical studies have shown that PET scans are more accurate than other widely used tests such as stress testing, and SPECT (single photon emission computed tomography).

“Many times these tests are associated with false positive results. They will show results that indicate coronary heart disease where none exists.” He warns that false positives can lead to people undergoing unnecessary procedures.

“Because PET scans are so accurate, they are often used to confirm other tests if a false positive is suspected,” he says.

Dr. Qamar paused. The teacher in him surfaced and he explained that coronary heart disease results from a narrowing or blockage of the vessels that feed the heart muscles. “As plaque or calcifications build up on the inside of the arteries, blood flow to the heart muscle is reduced. A PET Myocardial Perfusion Imaging test can show when this is happening. That is the instant value to such a test,” he says.

He goes on to explain that because reserve vessels will preserve normal flow to the heart as long as possible, an exercise test is normally used to see areas of the heart with reduced blood flow.

“Using a radioactive drug that shows the blood flow to tissues, a PET scan will show normal or abnormal patterns of blood flow to the left ventricle of the heart. The muscle tissue around the left ventricle pumps blood to the rest of the body and adequate pumping power is needed for our bodies to function well. If blood flow to this heart muscle is restricted by a blockage, then the blood flow picture will show a deficit. Knowing this will help the doctor identify the best plan of treatment,” he explains.

He points out that screening is an important way to detect coronary heart disease because the symptoms may not be noticeable or may be very mild. “Certain categories like people who have high blood pressure, or are not physically active, have high blood cholesterol, smoke or have a history of smoking, or are obese are at a greater risk for developing coronary heart disease. Finding coronary heart disease early is important, because it can lead to a heart attack.”

Dr. Qamar explains PET scanning involves an extremely expensive positron emission camera, an on site nuclear generator, and use of ultra-short half life radioisotopes such as Rubidium and FDB. “The test takes place inside a PET scanner.”

He describes the device as being a large machine shaped like a ring standing on edge. “The person having the test lies on a bed and the bed passes slowly through the center of the ring. A small amount of liquid, a tracer, is introduced into a vein. The person receives an injection of a drug that increases blood flow through the normal arteries, but the blood flow will not be increased in arteries that are blocked or in tissue that is damaged. The differences in blood flow are detected by the PET scanner. It gives us a picture of the blood flow to the heart tissue and allows us to identify problem areas.”

He says the patient must lie still during the PET scan so that the machine can produce clear images of your heart. “The test takes about 30 minutes and the patient must sign a consent form before having this test. They will be told not to eat anything for four to six hours before the PET scan, although they will be able to drink water.” He explains that it is important to tell your doctor about any prescription and over-the-counter medicines that you are taking, because they may interfere with the test.

“People who take insulin injections for diabetes may also need special preparation,” he says. It is also important to mention if you have any allergies.

Dr. Qamar says, “A PET scan can reveal the size, shape, position, and some function of the heart, so your doctor can make sure it is working as well as it should. It is most often used when other tests, such as cardiac stress tests do not provide enough information. This test can be used to diagnose heart problems and show areas in which there is poor blood flow to the heart.”

He goes on to say that several PET scans may be taken to determine how well you’re responding to treatment for heart disease and for that reason the Institute of Cardiovascular Excellence (ICE) is excited and proud to offer this amazing technology to its patients beginning August 2010.

Dr. Qamar smiles with pride and says, “It is just one more tool for us to use to help our patients live longer and more productive lives.”

for information contact:

Institute of Cardiovascular Excellence
Dr. Asad U. Qamar MD, FCCP,
FACC, FACP, FSCAI
Clinical & Interventional Cardiology
4600 SW 46th Ct. Suite 340
Ocala, FL 34474
Office: 352.854.0681
Fax: 352.387.0390
1400 U.S. Hwy 441 N. Suite 531
The Villages, FL 32159
Office: 352.509.9295
Fax: 352.509.9296