Language
Country/Area
No result found
The Secret of the Cardiac Stress Test: How It Reveals Hidden Cardiovascular Disease?
A cardiac stress test is a cardiology test designed to evaluate the response of the cardiovascular system to external stress. This stress response can be stimulated by exercise (usually on a treadmill) or intravenous medication to stimulate the heart rate. During this process, the heart's work intensity is gradually increased and is monitored using an electrocardiogram (ECG). As the heart works, its electrical rhythm and broader electrophysiology are observed. Pulse rate, blood pressure and symptoms such as chest discomfort or fatigue are also monitored in real time by clinical staff.
Abnormal blood pressure, heart rate, ECG, or worsening of physical symptoms may indicate coronary artery disease.
While stress tests can detect heart abnormalities such as irregular heartbeats and problems with the heart's electrical conduction, their accuracy in detecting coronary artery disease is limited. Many times, even if the test results show normal, the risk of potentially unstable coronary plaques rupturing and causing a heart attack in the future cannot be ruled out. That's because stress tests usually only detect arteries that are severely narrowed (about 70 percent or more).
Stress test and echocardiogram
Stress testing is often performed along with an echocardiogram, which allows comparison of structural differences before and after the test. A static echocardiogram is obtained first, and then stress is induced with exercise or chemical methods (such as purinergic drugs). Once the target heart rate is reached, a stress echocardiogram image is obtained, and the two sets of images are compared to examine the heart for motion wall abnormalities, an important tool for detecting obstructive coronary artery disease.
Cardiopulmonary exercise stress test
Cardiopulmonary exercise stress testing is usually performed by simultaneously measuring respiratory gases (eg, oxygen saturation, VO2max). Common indications include the assessment of transient dyspnea, pre-heart transplantation testing, and prognosis and risk assessment in patients with heart failure. This test is also commonly used in sports science to measure maximum oxygen uptake (V̇O2 max) in athletes. In 2016, the American Heart Association issued an official scientific statement advocating for the quantification of cardiorespiratory fitness as a clinical vital sign and for regular assessment in clinical practice.
Stress testing using nuclear markers
Nuclear stress tests use gamma cameras to image radioactive isotopes injected into the blood, the most famous example being myocardial perfusion imaging. Usually, after injecting a radioactive tracer (such as Tc-99) during the test, imaging data will be obtained at rest and during exercise. This test more accurately identifies areas of reduced relative flow in the myocardium, providing important information for assessing the status of the coronary arteries.
Recommended uses for this program
According to the recommendations of the American Heart Association, EKG treadmill testing is preferred for patients with moderate risk of coronary heart disease. Although the test's accuracy has limitations, it can serve as an initial assessment and guide subsequent diagnosis and treatment.
The data from the cardiac stress test only represents a momentary state and does not fully reflect the patient's heart health.
Diagnostic value
Current stress testing methods that provide information for diagnosing and managing heart-related conditions include treadmill testing and nuclear testing, among others. Each of these tests has unique sensitivity and specificity, but in general they should be considered within the context of the larger management of heart disease.
Contraindications and Termination Conditions
Cardiac stress testing is generally not recommended for asymptomatic and low-risk patients. Some studies show that such screening may not improve patient outcomes. Therefore, caution must be exercised when interpreting these test results unless high-risk markers are present.
Adverse reactions
Some potential side effects of a cardiac stress test include heart palpitations, chest pain and difficulty breathing, and in some cases there may be a small increase in the risk of cancer from tests using radioactive tracers.
Drugs cause inner stress
Drug stress testing often relies on the phenomenon of coronary artery seizure, using drugs such as albendazole and furosemide, and can be used for follow-up evaluation of patients with severe arterial disease or poor exercise ability.
Historical background
Cardiac stress testing has been used as an important diagnostic and prognostic assessment tool since the 1960s. As awareness of heart disease has increased, related testing techniques have continued to evolve to assess inducible myocardial ischemia.
This series of complex testing instruments are not only used for diagnosis, but also become an important tool for medical staff to understand the heart health status of patients. But how many blind spots do we still have in our understanding of heart health?
