Angina: types, symptoms, treatment, and prophylaxis

Angina manifests in attacks of sudden heart pain due to an acute cessation of blood supply to the myocardium (heart muscle). It is a clinical form of ischemic heart disease.

Pathogenesis

In most cases, angina is due to atherosclerosis of the coronary arteries of the heart; the initial stage of the latter limits the expansion of the lumen of the artery and causes an acute deficit of blood inflow to the heart muscle in physical and/or emotional overstrain. This is called stable angina. In atherosclerosis causing narrowing of the artery by more than two-thirds, an attack due to blood deficit occurs even at moderate stresses.

The appearance of an attack is facilitated by a decrease in blood flow to the orifices of the coronary arteries (especially lower blood pressure value drop of any, including medicinal, origin or a drop in cardiac output in tachyarrhythmias, venous low pressure); pathological reflex influences from the biliary tract, esophagus, cervical and thoracic spine with their concomitant diseases; acute narrowing of the coronary artery (non-occlusive thrombus, puffiness of the atherosclerotic plaque).

The main mechanisms of the attack subsiding:

- Rapid and significant diminishing in the work of the heart muscle (stopped load, the effect of nitroglycerin);
- Restored blood circulation in the heart arteries;

The main conditions for reducing the frequency and termination of attacks:

- Adaptation of the patient's load regime to the reserve capacity of their coronary bed;
- Development of pathways of roundabout blood supply to the myocardium;
- Abatement of manifestations of concomitant diseases;
- Stabilization of the systemic circulation;
- Development of myocardial fibrosis in the area of its ischemia.

Symptoms, course

With angina, pain is always distinguished by the following symptoms:

- Happens as an attack, i.e. it has a clear onset, fading, and ending;
- Happens under certain circumstances;
- Starts fading in the use of nitroglycerin (in 1 - 3 minutes after sublingual intake).

Conditions for the appearance of an attack of angina: most often - walking (speeding up, going uphill, walking after a meal or with a heavy load), other physical effort, and/or significant emotional stress. Pain enhances with the increase of physical or emotional load and fades when effort stops within minutes.

The named three features of pain are enough for making a clinical diagnosis of an attack of angina and for the differentiation of it from various pain sensations in the in the chest.

It is possible to make a preliminary diagnosis at the first patient's visit but it is necessary to observe the course of the disease and analyze the data of repeated episodes and examinations. The following signs make the diagnosis of angina more certain but their absence does not exclude this diagnosis:

- Allocation of pain behind the breastbone (most typical); rarely - in the neck, in the lower jaw and teeth, in the hands, in the shoulder and scapula (more often on the left), in the heart;
- The nature of the pain - pressing, squeezing, less often - burning (heartburn-like);
- The attack is accompanied by increased blood pressure, paleness of the skin, sweating, fluctuations in heart rate.

All this characterizes exertional angina. The comprehensiveness of the medical questioning determines the timeliness and correctness of the diagnosis. It should be kept in mind that often the patient with the symptoms reports them to the doctor as "not related to the heart", or, on the contrary, fixes attention on diagnostically secondary sensations "in the region of the heart".

Rest angina attack (unstable angina), contrary to exertional, stable angina, occurs without physical effort, more often at night. But otherwise retains all the features of a severe attack of stable angina and is often accompanied by a feeling of lack of air, suffocation.

In most patients, the course of angina pectoris is characterized by relative stability. This is understood as a certain age of the onset of signs of angina pectoris, the attacks of which during this period changed little in frequency and strength, occur when the same conditions are repeated or when similar conditions arise, are absent outside these conditions and subside under rest conditions (exertional angina) or after taking nitroglycerin. The intensity of stable angina pectoris is classified as the so-called functional class (FC).

FC I includes persons in whom stable angina pectoris is manifested by rare attacks caused only by excessive physical exertion. If attacks of stable angina pectoris occur during normal loads, although not always, such angina is referred to FC II, and in the case of attacks at low (household) loads - to FC III. FC IV is recorded in patients with attacks at minimal exertion, and sometimes in their absence.

Angina pectoris should alert the doctor if: the attack has arisen for the first time, but especially - if the attacks that have arisen for the first time become more frequent and intensify from the very first weeks of the disease; the course of angina pectoris loses its stability: the frequency of attacks increases, they occur in conditions different than before (at lower loads, stresses), appear outside the stresses (at rest, in the early morning), as if they move from FC I - II to III - IV FC; that is, the course of angina pectoris has changed, acquiring substantially new characteristics.

ECG changes

ST-segment decrease, T-wave inversion, arrhythmias, as well as a slight increase in the activity of serum enzymes (CPK, LDH, LDH1, ASAT), as a rule, are absent in such cases, but the presence of these signs additionally confirms the instability of angina pectoris. Preinfarction angina does not always end with a heart attack (the probability of a heart attack is about 30%); this must be taken into account in clinical diagnosis.

Occasionally, the so-called variant (vasospastic) form of angina pectoris occurs, which is characterized by the spontaneous nature of the attack, recorded on the ECG by sharp elevations of the ST segment, refractoriness to beta-blockers (anaprilin and obzidan), but sensitivity to calcium ion antagonists (verapamil, plendil), corinfar.

The basis for the diagnosis of any of the forms and variants of the course of angina pectoris is a correctly constructed and carefully conducted questioning of the patient. In unclear cases, a test with physical activity (bicycle ergometric test) is carried out in order to reveal the latent existing coronary insufficiency. The tactics of establishing a diagnosis is determined by the following schematic sequence for solving the main questions:

- Coronary (anginal) nature of pain?
- Are there signs of preinfarction angina?
- Isn't the present exacerbation during ischemic heart disease associated with the influence of non-cardiac (concomitant) diseases?

Only a convincingly reasoned negative answer to the first of the three questions gives the right to search for another cause (source) of pain: the discovery of another disease in a patient as a source of his pain cannot exclude angina attacks as a manifestation of coronary heart disease.

Complications of angina itself are not observed if it does not become an expression of the progression of cardiosclerosis and if it does not turn out to be the first manifestation of developing myocardial infarction. Therefore, an attack of angina pectoris, which lasted for 20-30 minutes, as well as unstable angina pectoris, require an electrocardiographic examination in the coming hours (day) and determine the presence of reactive shifts in the activity of a number of enzymes in the blood, body temperature.

Determining the annual risk of cardiovascular death

Treatment

Relief of an attack:

- Keep calm, preferably in sitting position;
- Take nitroglycerin under the tongue (1 pill), repeated use of the drug in the absence of effect after 2 - 3 minutes;
- Take orvalol (valocardin) - 30 - 40 drops inside with sedative purpose;
- Arterial hypertension during an attack does not require urgent medical measures, since a drop in blood tension occurs spontaneously in most cases;
- If nitroglycerin is poorly tolerated (bursting headache), then a mixture of 9 parts of 3% menthol alcohol and 1 part of 1% nitroglycerin solution is prescribed, 3-5 drops on sugar per dose.

The prognosis in the absence of complications is relatively favorable. The ability to work is preserved, but with the restriction of work requiring significant physical effort.

Treatment aimed at the support of heart function:

- First-line medications: Beta-blockers and/or calcium channel blockers (Plendil);
- Second-line medications: long-acting nitrates (ivabradine, nicorandil, or ranolazine);
- Additional medicines: trimetazidine.

In patients with lack of symptoms but a large zone of ischemia (impaired blood circulation), it is highly advisable to include first line beta-blockers daily.

For the lowering of the coronary events and prevention of atherosclerosis development the following medications are prescribed:

- Low doses of aspirin;
- In case of aspirin intolerance – Clopidogrel;
- Statins (for all patients with stable angina);
- ACE inhibitors in case of heart failure, hypertension, or diabetes.

General recommendations for stable angina treatment:

- Smoking cessation, daily physical exercising, use of antiplatelet agents, treatment of dyslipidemia (high amount of lipids in the blood) and high blood pressure are the main methods of prevention of death due to myocardial infarction (heart attack) in people with stable angina.
- If stable angina restricts tolerance of usual physical loads and worsens the quality of life, systemic anti-angina therapy must be appointed. It is based on beta-blockers or calcium channel blockers.
- Second-line medications can be used as an addition to the main therapy or as a replacement when the firs-line drugs cannot be used.
- The therapy must be started with a single medication. The addition of other medicines is possible only in the lack of the needed effect. Moreover, the dosage of the first-line drug must be adjusted in combined therapy.
- Patients in whom the symptoms are poorly controlled by the use of two antianginal medications should be considered candidates for revascularization, i.e. surgery for the improvement of blood circulation in the myocardium.

Post by: John Avery, General Practitioner, Manchester, United Kingdom