Stenocardia tension: diagnosis

The diagnosis of "angina" is suggested in the case of the appearance of typical discomfort in the chest, increasing with physical activity and decreasing at rest. Patients who have chest discomfort lasting more than 20 minutes or who are at rest or who have had syncope or heart failure belong to the group of patients with acute coronary syndrome. Discomfort in the chest can also be caused by digestive disorders (for example, gastroesophageal reflux, esophagus spasm, dyspepsia), inflammation of the rib cartilage, anxiety, panic attack, hyperventilation and various heart diseases (such as pericarditis, mitral valve prolapse, supraventricular tachycardia, atrial fibrillation) , even in those cases when coronary blood flow is not changed.

Examination. In the presence of characteristic symptoms, an ECG is prescribed. Because the symptoms of angina disappear quickly at rest, it is very rare to perform an ECG during an attack, except for a stress test. If the ECG is carried out during an attack, it is possible to see the changes characteristic of transient ischemia: segment depression (typical change), segment elevation above the isoline, decrease in the height of the Z wave, violation of intraventricular conduction or conduction of the bundle of the head, development of arrhythmia (usually ventricular extrasystole) . Between the seizures, ECG data (and usually LV functions) at rest are within normal limits in approximately 30% of patients with a typical history of angina pectoris, even in cases of three vessels. In the remaining 70% of cases, the electrocardiogram reflects a previous myocardial infarction, the presence of hypertrophy or nonspecific changes in the segment, the T wave (ST-T). Changes in resting ECG data (without additional study) do not confirm or disprove the diagnosis.

More accurate methods of investigation include a stress test with ECG or visualization of the myocardium (eg, echocardiography, radioisotope study), and coronarography. These studies are necessary to confirm the diagnosis, assess the severity of the disease, determine the appropriate level of physical activity for the patient and assess the prognosis.

Initially, non-invasive studies are prescribed. For the diagnosis of IHD, stress echocardiography and perfusion photon-emission computer tomography of the myocardium or PET are the most reliable. However, these studies are more expensive than a simple stress-ECG.

In the event that the patient has normal ECG data at rest and can tolerate physical stress, use a stress test with an ECG. In men with discomfort in the chest resembling angina, the ECG stress test has a specificity of 70% and a sensitivity of 90%. Sensitivity in women is similar, but the specificity is lower, especially in women younger than 55 years (<70%). At the same time, women are more likely than men to have ECG changes at rest in the absence of IHD (32% vs 23%). Although the sensitivity of the method is high enough, a stress test in combination with an ECG can skip a serious CHD (even with left main artery lesions or a three-vessel lesion). In patients with atypical symptoms, a negative result of an ECG stress test usually excludes stress angina and coronary artery disease; a positive result may indicate the presence or absence of myocardial ischemia and requires further research.

When changing the ECG data of rest, false-positive segment changes are often encountered in a stress-ECG, in which case a visualization of the myocardium is necessary against the background of a stress test. You can use stress tests with physical or pharmacological (with dobutamine or dipyridamole) load. The choice of the visualization option depends on the technical capabilities and experience of the expert. Visualization methods help to assess LV function and response to stress, identify areas of ischemia, infarction and viable tissue, determine the scope and volume of the myocardium in the risk zone. Stress echocardiography can also determine mitral regurgitation caused by ischemia.

Coronary angiography is the standard for diagnosing IHD, but it is not always necessary to confirm the diagnosis. This study is primarily designed to assess the severity of the pathology of the coronary arteries and the localization of lesions, in those cases where there is a possibility of revascularization [percutaneous angioplasty (PTCA) or coronary artery bypass grafting]. Angiography can also be prescribed if knowledge of the anatomy of the coronary vessels is necessary to determine the performance and the development of a lifestyle (for example, stopping work or playing sports). The obstruction to blood flow is considered physiologically significant when the lumen diameter is reduced by more than 70%. This decrease is directly correlated with the presence of angina pectoris in those cases, if no spasm or thrombosis of the artery is attached.

Intravascular ultrasound provides visualization of the structure of the coronary artery. An ultrasonic sensor placed on the tip of the catheter is inserted into the coronary artery during angiography. This study allows you to get more information about the anatomy of the coronary arteries than other methods. Intravascular ultrasound is prescribed in case of ambiguity of the nature of arterial damage or when the apparent seriousness of the disease does not correspond to the symptoms. When used during angioplasty, the method guarantees optimal placement of the stent.

[1], [2], [3], [4], [5]