Acute pericarditis: danger, examinations, treatment

Author: Strokina O.A., therapist, doctor of functional diagnostics.
October, 2020.

ICD-10 code:  I30.0, I30.1, I30.8, I30.9 and I01.0

Pericarditis is an inflammatory process that develops in the pericardium (outer lining of the heart) with or without the formation of an effusion in the cavity (between the two sheets of the pericardium). The acute process is characterized by a rapid onset, the presence of clear symptoms (prolonged acute pain in the region of the heart, which increases with movement, pericardial friction noise) and a course of no more than 1 weeks. It is treated mainly conservatively, but sometimes surgical intervention is necessary.

According to the results of pathological and anatomical studies, pericarditis occurs in 3-6% of people.

In most cases, viruses (Coxsackie, Ebstein-Barr, mumps, rubella, HIV, cytomegalovirus) become the cause of the acute course of pericarditis.

In second place in terms of prevalence are idiopathic acute pericarditis, that is, those where the cause could not be identified. They respond well to treatment.

Much less often, pericarditis, which has developed as a result of a malignant neoplasm, of a bacterial nature, is detected. Such acute processes are often accompanied by the development of complications.

Views

Depending on the substance, which mostly accumulates in the pericardial cavity, acute pericarditis is divided into

• Dry (fibrinous). During inflammation, more fibrin protein penetrates through the vessel wall into the cavity than fluid. Fibrin is deposited on the walls of the pericardium and causes a noise when the sheets of the membrane rub against each other during the contraction of the heart.
• Exudative (exudative) pericarditis develops when the main fluid penetrates the vessel wall. As a result, a large amount of effusion accumulates in the pericardial cavity, which impairs the hearing of heart sounds.

Symptoms

The clinic of acute pericarditis develops quickly and usually resolves within 1 week. With a more protracted course of the disease, the process passes into a subacute stage, which is more difficult to treat.

Acute pericarditis is diagnosed by identifying 2 of 4 of the following criteria:

• Chest pain. The symptom occurs in more than 85-90% of cases. The pain is acute, occurs suddenly. Weakens while sitting when the trunk is bent forward.
• Pericardial friction murmur is detected less often - in less than 33% of cases. It is similar to a shallow scratching sound that is best heard on the left side of the sternum.
• Changes in the electrocardiogram with pericarditis are recorded in 2/3 of the patients and are characterized by an increase in the ST segment. This ECG is similar to film changes in myocardial infarction and early ventricular repolarization syndrome.
• The presence of effusion in the pericardial cavity according to the results of echocardiography (ultrasound of the heart). Reveal more often a moderate amount.

The patient may additionally develop other symptoms characteristic of systemic inflammation, infection, and malignant neoplasm. It can be:

• fever (increased temperature);
• heat;
• chills;
• severe weakness;
• nausea;
• dizziness, up to loss of consciousness;
• pains of other localization and many others.

All additional symptoms are different in each case and depend on the underlying cause of the disease.

Diagnostics

The first signs that can prompt a doctor to think about pericarditis are detected at the examination stage - this is a pericardial friction noise. If necessary, the specialist asks questions to clarify a clearer picture. To confirm the diagnosis, the doctor prescribes instrumental diagnostic methods:

• Echocardiography (Ultrasound of the heart) is the most informative method for diagnosing pericarditis. With the help of ECHO-KG, the doctor can see and describe the contents of the pericardial cavity for the presence of various kinds of inclusions (blood clots, fibrin).
• Electrocardiogram. A common feature of acute pericarditis is widespread ST elevation on film.
• A chest x-ray is recommended for all patients. An increase in the shadow of the heart is detected on the roentgenogram only in the case of effusion greater than 300 ml. However, the study reveals signs of involvement in the inflammatory process of the pleura (outer lining of the lungs).

Also, laboratory blood tests are prescribed:

• General blood analysis. The inflammatory reaction of the blood often accompanies acute pericarditis - an increase in the level of leukocytes, the appearance of their young forms (stab, young), a high level ESR (sedimentation rate of erythrocytes).
• Blood chemistry - C-reactive protein (increased), markers of myocardial damage (troponins, CF-fraction of creatine phosphokinase can be increased when the myocardium is involved in the process).

The listed examinations are included in the mandatory list of diagnostics of acute pericarditis.

After examination, finding out the anamnesis, carrying out the listed tests, usually the doctor already has guesses about the cause of the disease. To confirm the diagnosis, the following additional examinations are carried out:

• intradermal tuberculin test (Mantoux test, diaskintest) for the diagnosis of tuberculosis;
• blood culture for suspected infective endocarditis;
• virological studies by ELISA and PCR methods;
• analysis for HIV, hemophilic infection;
• exclusion of chlamydial and mycoplasma infections by ELISA and PCR;
• determination of antinuclear factor, rheumatoid factor, antibodies to cardiolipins (with systemic lupus erythematosus, rheumatoid arthritis and others);
• titer antistreptolysin-O (with rheumatism);
• determination of antibody titers to myolemma and actomyosin in blood serum (if perimiocardial tuberculosis is suspected);
• determination of the level of thyroid hormones (with hypothyroidism).

Sometimes, to make a diagnosis, the doctor needs additional studies with higher resolution to clearly visualize the pericardium and its cavity. Such studies include computed tomography and magnetic resonance imaging.

The post-Soviet countries are characterized by a high incidence of tubercle bacillus (the causative agent tuberculosis) among the population, which often causes inflammation of the outer shell of the heart and related complications. In this regard, it is recommended in the early stages to determine the etiology of acute pericarditis in the following ways:

• Pericardiocentesis with drainage of the pericardial cavity. The fluid taken from the pericardial cavity is sent for PCR and histochemical analysis to identify the infectious or tumor etiology of the disease. Pericardiocentesis with drainage of contents is also a mandatory emergency procedure if cardiac tamponade is suspected.
• Pericardioscopy with pericardial biopsy¹. A specialist inserts an endoscope with a camera into the pericardial cavity, examines it and takes a piece of pericardial tissue for histological and cytological examination.

Treatment

Acute pericarditis is treated only in a hospital by cardiologists, sometimes cardiovascular surgeons. This is necessary to determine the exact cause of the disease and point specific therapy, which will further exclude the possibility of chronicity of the process.

First of all, physical activity is limited up to bed rest until the level of CRP (C-reactive protein) normalizes and symptoms disappear. For athletes, as for a special cohort of patients, it is recommended to return to training only after the normalization of all the results of diagnostic studies (analyzes, ECG, echocardiography). The minimum period for limiting the loads for them is considered 3 months from the moment of the onset of the disease.

The main thing in the treatment of any disease is to cope with its cause. If it is detected in the case of acute pericarditis, then etiotropic treatment is indicated (antibiotics, hormonal and other drugs, depending on the cause).

The mainstay of therapy for acute pericarditis is aspirin or NSAIDs (non-steroidal anti-inflammatory drugs - ibuprofen, indomethacin). Naturally, the choice of the drug and its dosage should be based on concomitant diseases, the patient's age and contraindications. Only the attending doctor will prescribe the correct treatment. The effectiveness of treatment with this class of drugs is assessed 2 weeks after the start of administration.

Colchicine is also used in the treatment of acute pericarditis as part of complex therapy. It is able to prevent the transition of the disease to a recurrent course and a chronic stage. The dosage is strictly dependent on body weight.

Second-line drugs, that is, if there is no effect from NSAIDs and aspirin or there are contraindications to them, are glucocorticosteroids (prednisolone, hydrocortisone). But with their use, the risk of chronicity of the process and the emergence of dependence on this class of medicinal substances increases.

Surgical methods for the treatment of acute pericarditis are based on pericardiocentesis with drainage of fluid from the pericardial cavity. More often it is necessary with the development of cardiac tamponade.

Forecast

In acute pericarditis of idiopathic or viral etiology, the long-term prognosis is favorable. Complications usually occur with specific underlying diseases (malignant neoplasms, tuberculosis). In such cases, there is a high risk of developing a life-threatening condition - cardiac tamponade (compression of the heart by pericardial effusion) and constriction (compression of the heart due to soldering of the pericardial sheets, which does not give it normal shrink).

The prognosis also worsens if colchicine is not included in the treatment.². Without it, the risk of recurrence of the process reaches 15-30%.