Functional class of angina pectoris - description, classification and features

Experts note a frightening increase in the number of heart diseases among the population. In addition, the age at which they first manifest is greatly reduced. As a rule, people do not pay attention to symptoms until a disaster occurs, but even a minor malaise can be a sign of a serious heart pathology. Classification according to functional classes of angina clearly shows the "secretiveness" of the disease. Changes occur so gradually that people get used to them and do not consider it necessary to be treated.

Classification of stable angina

There are several varieties of angina pectoris, each of which has both common characteristics for the group and unique symptoms that make it possible to distinguish it among others. Stable angina is a form of angina pectoris. It is characterized by the appearance of pain during exercise and the disappearance of uncomfortable sensations at rest.

There are the following functional classes of angina pectoris:

1. The first class - pains appear only at excessive loads and quickly pass in rest.
2. The second class - discomfort in the chest when walking more than 300 meters or climbing the stairs.
3. The third class - pains appear after overcoming a distance of 150 meters or walking on the steps to one floor.
4. The fourth class - attacks happen at easy physical activity and in rest.

Unstable angina

Unlike the previous species, unstable angina manifests itself as intense pain that is not associated with physical exertion. In addition to the functional class, angina of this type is divided into four forms:

1. For the first time arisen angina. It is considered as such if the first attack occurred no later than two months ago. It is dangerous because it may be a symptom or precursor of myocardial infarction. It can be transformed into a stable type of disease.
2. Progressive. Attacks become more frequent and stronger, signs of myocardial hypoxia appear on the cardiogram. It is possible to change the functional class to a lower one.
3. Early postinfarction. Pain in the chest area persists for two weeks immediately after myocardial infarction.
4. Vasospastic. It is called still variant, or stenocardia of Prinzmetall. This form is characterized by night attacks, not related to physical activity.

Classification by Braunwald

In order to determine the likelihood of myocardial infarction, the classification proposed by Braunwald for the characterization of pain is used. It does not affect the functional class of angina, but only extends the diagnostic capabilities of the doctor without the use of instrumental methods of investigation.

The first class implies under itself the first-time angina strain, the symptoms of which are intensified during the last two months.

The second class is rest stenocardia or its subacute form, but only if it did not appear less than two days ago.

The third class includes acute angina and rest stenocardia, which has manifested itself in the last forty-eight hours.

On provoking factors

There are several other classifications of angina pectoris. Functional classes are not the only marker for determining severity and variants of the course of the disease.

On the factors that can provoke the disease, distinguish such varieties:

• A - anemia, hypoxia, infection and other non-coronary causes;
• B - primary angina of unexplained etiology;
• C - postinfarction variant of the disease, formed within two weeks after the acute process.

In the first case (A) the doctor deals with secondary angina and is forced to treat not only her but also the primary focus. In the other two cases (B and C), the situation is different, since the causes of the disease lie directly in the organ itself.

Classification by Risic

Functional classes of stable angina pectoris can be supplemented with the Rizik classification, which, in addition to subjective sensations, also takes into account the ECG indications.

1. The first A-class - the symptoms of angina intensify from an attack to an attack, but there are no changes on the cardiogram.
2. The first B-class - with an increase in the intensity of pain, there are objective changes on the ECG.
3. The second class - the cardiogram reflects the changes characteristic for the first arising angina of tension.
4. The third class - on the ECG there are signs of angina pectoris.
5. The fourth class - in addition to stenocardia rest, on the cardiogram, deterioration of the dynamics of the heart and hypoxia of the myocardium are noted.

Classification of the Canadian Heart Society

One of the options for classifying angina by functional class was proposed by Canadian cardiologists in the mid-2000s. It includes five classes:

1. Zero, when the symptoms of the disease are absent in both exercise and rest.
2. First. A significant physical load or emotional overexertion can provoke an attack of pain behind the sternum.
3. Second. Minor discomfort behind the sternum appears with intense physical activity.
4. The third. Pain and shortness of breath occur regularly during daily activities.
5. Fourth. Symptoms can cause even the slightest load.

Such a classification is used by doctors in the Western Hemisphere, for domestic doctors, the ranking that was given at the very beginning is more familiar, therefore, the diagnosis is written, for example: "IHD: stress angina, functional class 2". But this does not mean that our specialists are not familiar with this division of functional classes.

Variable angina pectoris

Stable angina pectoris, whose functional classes are described above, also includes a variant type of flow. He has many names, but the essence remains the same: seizures of chest pain appear suddenly, without connection with physical exertion, usually at night or in the morning. An uncomfortable sensation is felt in the spasm of the arteries feeding the heart, but they usually do not reveal any morphological changes that would indicate the presence of atherosclerosis.

Patients who regularly suffer from fits of variant angina pectoris may not pay attention to the development of such a formidable disease as myocardial infarction, since the symptoms will be similar. Such negligence can cost a person's life if he does not receive medical care. Correction of attacks is carried out with the help of calcium antagonists or nitrates.

Types of angina pectoris

Once the functional classes (FC) of stress angina are isolated, there are other types of angina pectoris. One of the classifications uses flow characteristics to distinguish four variants of angina pectoris manifestation:

1. First emerged: pain lasts about a month (but not more than two), they are frequent and intense, directly related to the physical activity of a person. Through time this species passes into a stable form. Adverse is considered the option, when during an attack there is a rise in the ST segment on the cardiogram.

2. Progressive: if the frequency and severity of pain attacks increase even on the background of treatment, this indicates an aggravation of the disease, a decrease in the compensatory abilities of the organism and a high risk of a heart attack. Patients may experience anxiety and fear of death, attacks of suffocation.

3. For the first time the arisen angina of rest: if the heart muscle does not receive enough blood because of a reduced cardiac output or coronary artery atherosclerosis, angina attacks can also be observed at rest. Most often, pain occurs in a dream, since the horizontal position of the body changes the amount of venous blood that returns to the heart, and consequently, the subsequent cardiac output.

4. Stable angina: the frequency and intensity of seizures do not change over time, the disease is well controlled by drugs and does not threaten critical conditions. But do not treat this type of disease irresponsibly, because at any time, the deterioration of the state is possible.