Overall, non-invasive CT angiograms accurately detected or ruled out artery blockages in 91 percent of patients, compared with 69 percent for stress testing.
A coronary angiogram is a type of X-ray used to examine the coronary arteries supplying blood to your heart muscle. It's considered to be the best method of diagnosing coronary artery disease - conditions that affect the arteries surrounding the heart.
The nuclear stress test offers a comprehensive evaluation of blood flow, heart function, treatment effectiveness, and risk stratification. It is the most reliable diagnostic tool among the three for detecting or ruling out coronary artery disease.
(As noted above, it will miss almost all of the blockages that narrow an artery less than about 65%) It has a specificity of about 90%, meaning that 10% of the abnormal nuclear stress tests will turn out not have a significant blockage.
“Most people think a stress test identifies blockages to the heart, but it does not,” explains Aristotelis Vlahos, M.D., director of the Cardiac Catheterization Lab at Riverview Medical Center. “It looks at blood flow to the heart muscle and determines if blood flow is adequate or not.
A nuclear cardiac stress test helps diagnose and monitor heart problems such as coronary artery disease. A healthcare provider connects you to an EKG machine, injects a tracer into your bloodstream and takes images of blood flow to your heart before and after exercise.
The test is done to see if your heart muscle is getting enough blood flow and oxygen when it is working hard (under stress). Your provider may order this test to find out: How well a treatment (medicines, angioplasty, or heart surgery) is working. If you are at high risk for heart disease or complications.
Although blockages can occur in other arteries leading to the heart, the LAD artery is where most blockages occur. The extent of the blockage can vary widely from 1% to 100%. “Many people can survive widow-makers if we get them treatment right away,” Niess said.
Many people are told that a 70 percent blockage of the coronary artery will require a stent, but ultimately, it depends on the individual, their current health status, and the likelihood that the stent will improve the overall quality of life.
The angiogram and cardiac catheterization are the most definitive tests, better than a nuclear stress test, but both use significant radiation, and the cardiac catheterization uses a large catheter in the artery, which can cause complications.
A stress echocardiogram does not use ionizing radiation; the small amount of energy delivered by medical ultrasound has never been shown to harm tissues. The results of numerous studies comparing the accuracy of nuclear stress testing with stress echocardiography show that they are reasonably close.
Coronary catheter angiograms are useful in identifying plaques that cause stenosis; however, they often miss the soft plaque that is building inside the artery wall which is a more frequent killer than stenosis due to plaque.
A CT scan of the heart can show calcium deposits and blockages in the heart arteries. Calcium deposits can narrow the arteries. Sometimes dye is given by IV during this test. The dye helps create detailed pictures of the heart arteries.
An angioplasty may be all you need if it makes your blood flow better and there's less than 30% of your blockage left after the procedure. If an angioplasty doesn't create a large enough opening for blood to get through, you may need a stent. This tiny metal tube stays in your blood vessel to keep it open.
And as shown in the study, even levels of blood pressure that are generally considered “normal” may indeed be high enough to foster the development of atherosclerotic heart disease by more than fourfold above the risk faced by people with systolic blood pressures that are physiologically ideal.
Atherosclerosis, which causes diseases of the arteries, is a very common process. One of the biggest risk factors for atherosclerosis is age, so it is more common among people in their 60s and 70s, although there are many elderly people who don't have significant atherosclerosis.
Through angioplasty, our cardiologists are able to treat patients with blocked or clogged coronary arteries quickly without surgery. During the procedure, a cardiologist threads a balloon-tipped catheter to the site of the narrowed or blocked artery and then inflates the balloon to open the vessel.
Radiation exposure
However, the AHA notes that there is a possibility that even low levels of radiation may be harmful. A person should not have a nuclear stress test if they have low heart attack risk and no symptoms of heart issues.
Your doctor may elect to proceed with stress testing to help define your overall risk of heart disease. This is a very reasonable option. However, if you had a stress test within the past two years and you remain asymptomatic, there is no need to repeat the test until it has been at least two years.
They're Not Stressful
Stress in fact means putting additional expectations on the heart – this could be by simply walking on a treadmill, not running a marathon.
Your target heart rate during a stress test depends on your age. For adults, the maximum predicted heart rate is 220 minus your age. So, if you're 40 years old, the maximum predicted heart rate is 220 – 40 = 180.
Once you have exercised as much as you can, we will give you a second injection of the tracer so we can see the stress blood flow to your heart muscle. It is normal to feel tired, short of breath, heaviness of the legs while exercising.