A person who was usually in good health was recently diagnosed with coronary artery stenosis of 90% by coronary angiography after he often felt chest tightness and pain with normal electrocardiogram. Another patient, who had chest tightness and breath-holding from time to time and mild myocardial ischemia on ECG, was put under the cap of coronary heart disease 3 years ago and had been taking medication for treatment, but the effect was not good. Recently, coronary angiography was performed and no abnormality was found, which ruled out the diagnosis of coronary artery disease.
Nowadays, the incidence and mortality rate of coronary artery disease is increasing, and there is a trend of low age. Coronary angiography is the gold standard for the diagnosis of coronary artery disease, and it can clarify the presence, severity and extent of coronary artery lesions. This is the obvious benefit of coronary angiography, as the saying goes, “Seeing is believing”. However, on the other hand, the overuse of coronary angiography technology has become a major new clinical problem.
Myth: Coronary angiography is too random
With the continuous progress of medical technology, coronary angiography technology has become increasingly mature, the country’s major hospitals have been carried out one after another, the public also know a little about the examination. But we must realize that coronary angiography is a means to confirm the diagnosis of coronary heart disease, not a method to “screen” for coronary heart disease. Coronary angiography is an invasive test, the operation has certain risks, there are strict indications, not all patients with chest tightness, chest pain need to do angiography.
In some medical institutions, some doctors perform coronary angiography without any non-invasive examination for patients with suspected angina, resulting in a positive coronary angiography rate of less than 50% (more than half of those with angiography do not have coronary artery disease). In order to avoid unnecessary trauma and medical expenses, the majority of patients should do 6 non-invasive tests before coronary angiography to determine whether they need to do coronary angiography.
Correct view: 6 non-invasive tests should be done before imaging
1.Electrocardiogram.
It is the most basic, easy and practical method to diagnose coronary heart disease. Whether it is angina pectoris or myocardial infarction, the ECG during the attack will have typical changes when compared with before and after the attack. However, there are certain limitations of ECG examination, such as the sensitivity and accuracy of diagnosis is only about 70%; in the non-episode period, the ECG is normal in more than half of the patients; the “ST-T” changes based on ECG diagnosis of myocardial ischemia can also be caused by electrolyte disorders, drugs, autonomic disorders, diet, postural changes, and various other heart diseases. It can also be caused by electrolyte disorders, medications, autonomic dysfunction, diet, postural changes, and various other heart conditions.
Tip: If the ECG is abnormal, it is recommended to do the second test.
2.Electrocardiogram plate exercise test.
It is a good way to screen patients with coronary heart disease. The test induces myocardial ischemia by putting a load on the heart, and is more sensitive and accurate than resting ECG in diagnosing coronary artery disease, and is inexpensive, easy to apply and repeatable. During the examination, the subject walks on a moving plate apparatus, and the amount of exercise can be controlled by changing the rotation speed and slope of the plate. Cardiac monitoring is performed during exercise, and ECG is recorded and blood pressure is measured intermittently to ensure safety and to detect clues of myocardial ischemia in a timely manner.
Tip: If there is abnormality in the exercise plate test, coronary angiography is recommended.
3. Ambulatory electrocardiogram (Holter).
Conventional ECG can only record waveforms of tens of cardiac cycles at rest, while dynamic ECG can continuously record up to 100,000 ECG signals within 24 hours, which can improve the detection rate of transient arrhythmias and transient asymptomatic myocardial ischemic attacks.
Tip: If there are abnormalities in the ambulatory ECG, it is recommended to do the 2nd and 4th tests.
4. Echocardiography.
It can also examine the heart morphology, ventricular wall motion, and left ventricular function to exclude other cardiac diseases that can cause myocardial ischemia and angina attacks, such as heart valve disease and hypertrophic cardiomyopathy.
Tip: If the echocardiogram suggests a lesion in the coronary artery, it is recommended to do the second test.
5.Isotope examination.
That is, nuclear myocardial imaging, which can clarify the site and extent of myocardial ischemia. The detection rate of myocardial ischemia can be improved if a loading test (myocardial re-imaging) is performed in combination with injected drugs. It is indicated for patients with heart disease who cannot tolerate the exercise plate test.
Tip: If lesions are found, coronary angiography is recommended.
6.Spiral CT examination.
The application of multilayer spiral CT allows for non-invasive coronary CT angiography. Patients only need to inject contrast intravenously, and the cardiac CT examination can be completed within minutes, which is convenient and fast, but the image quality is not satisfactory at present.
Tips: If abnormalities are found, coronary angiography is recommended.
Tips: Chest tightness and chest pain are not necessarily coronary heart disease
Some patients’ cardiac symptoms may be caused by extracardiac disorders, such as liver and gallbladder disease, stomach disease, reflux esophagitis, as well as women’s menopause and neurasthenia. Most of these conditions can be diagnosed by taking a careful history and performing relevant noninvasive tests. People with hypertension, cardiomyopathy, heart valve disease and other cardiac disorders may also have obvious manifestations of myocardial ischemia, but they do not necessarily combine with coronary artery disease and do not necessarily need coronary angiography.