Pericardial effusion: what is it, symptoms, treatment, prognosis

What is pericardial effusion?

Pericardial effusion refers to the accumulation of fluid in the pericardial sac surrounding the heart. The pericardial sac consists of a thin visceral pericardium, which consists of one layer of cells attached to the cardiac epicardium, and a thicker fibrous parietal pericardium, composed of collagen and elastin, which is attached to the lungs, diaphragm, sternum, great vessels and other structures of the mediastinum surrounding heart. In a healthy person, the pericardial sac contains from 15 to 50 ml of serous fluid.

Signs and symptoms

The patient may have significant pericardial effusion without signs or symptoms, especially if the fluid increases slowly.

If symptoms of pericardial effusion do occur, they may include:

• dyspnea or shortness of breath (dyspnea);
• discomfort when breathing while lying down (orthopnea);
• chest pain, usually behind the breastbone or on the left side of the chest;
• fullness in the chest;
• swelling legs or abdomen.

Causes and risk factors

The etiology of pericardial effusion varies widely and can be divided into several categories:

• Infectious: Pericardial effusion can be caused by infection by a variety of viral, bacterial, fungal, and even parasitic pathogens.
• Inflammatory / rheumatologic: numerous autoimmune diseasesincluding systemic lupus erythematosus, rheumatoid arthritis and Sjogren's syndromecan cause pericardial effusion.
• Neoplastic: Both metastatic disease and primary cardiac tumors can cause pericardial effusion. Lungs' cancer Is the most common cause of malignant pericardial effusion.
• Trauma: Blunt, penetrating, and iatrogenic injury to the myocardium, aorta, or coronary vessels can lead to accumulation of blood in the pericardial sac.
• Cardiac: postinfarction syndrome (the so-called Dressler syndrome), cardiac surgery, rupture of the heart wall.
• Vascular: Type A aortic dissection may be complicated by cardiac tamponade.
• Idiopathic: Many cases of pericardial effusion are idiopathic.
• Other: There are many additional etiologies for pericardial effusion, including radiation, chronic kidney disease and renal failure, congestive heart failure, cirrhosis of the liver, hypothyroidismleading to myxedema, ovarian hyperstimulation syndrome and drug-induced.

Epidemiology

Pericardial effusion is possible for all ages and populations. The predominant etiology of effusion depends on demographic characteristics such as age, geography, and comorbidities. There are very few data on the prevalence and frequency of pericardial effusion. Viral pericarditisleading to effusion is the most common cause in developed countries. Pericardial effusion due to mycobacteria is common in developing countries tuberculosis. Bacterial and parasitic etiologies are less common.

Among non-inflammatory pericardial effusions, multiple malignancies can lead to pericardial effusion. In patients with pericardial effusion, malignant neoplasms account for 12% to 23% of cases of pericarditis. In HIV patients, pericardial effusion was noted in 5–43%, depending on inclusion criteria, with moderate to severe effusion in 13%. According to a study in pediatric patients, postcardiac surgery (54%), neoplasia (13%), renal (13%), idiopathic or viral pericarditis (5%) and rheumatologic (5%) were the main causes of pericarditis and pericardial effusions in children.

Pathophysiology

Pericardial effusion is an acute or chronic accumulation of fluid in the pericardial space. The effusion can be transudative, exudative, or bloody. The pericardium has limited elasticity, and in acute cases, 100 to 150 ml of fluid is required to induce cardiac tamponade.

The accumulation of fluid increases the pressure in the pericardial sac, which causes the heart, especially the right heart, to contract due to the thinner wall. Violation of the diastolic filling of the right side of the heart causes venous congestion. A decrease in left ventricular diastolic filling leads to a decrease in stroke volume.

Tachycardia and increased contractility is an initial compensatory response mediated by adrenergic stimulation to maintain cardiac output. However, over time, blood pressure and cardiac output gradually decrease.

In chronic conditions, pericardial effusion can become one to two liters in size before it causes cardiac tamponade if accumulation occurs gradually and the parietal pericardium has enough time to stretch and adapt to the increased volume.

Diagnostics

- History and physical examination.

The clinical presentation of pericardial effusion ranges from a clinically irrelevant incidental finding to life-threatening cardiac tamponade. This wide variation is largely due to the variable rate of pericardial fluid accumulation. Acute accumulation can cause impaired cardiac filling and a decrease in cardiac output with as little as 100 ml of fluid, while chronic and slow accumulation can lead to significant effusions of one to two liters, which do not cause significant hemodynamic effects.

• Anamnesis: patients with pericardial effusion due to pericarditis often complain of chest pain and shortness of breath with symptoms that improve while sitting and worsen when lying down due to contact of the inflamed pericardium with adjacent structures. Patients may also have symptoms not specific to pericardial effusion, including dyspnea, edema and fatigue. Other important elements of the history include questions regarding recent illness, malignant neoplasms, tuberculosis, and a history of vaccinations. a history of autoimmune disorders, chronic kidney disease or renal failure, or congestive heart failure, hypothyroidism, or liver diseases.
• Physical examination: pericardial effusion leading to pericardial tamponade should be differentiated in patients with cardiac arrest or with abnormalities of vital functions, including hypotension and tachycardia. Beck's classic triad (hypotension, distended jugular veins, and muffled heart sounds) occurs in only a minority of patients. Other unique signs of physical examination of pericardial effusion include Evart's sign (dullness of percussion at the base of the left lower border of the scapula in combination with tubular sounds of breathing and egophony). Physical examination of patients with suspected cardiac tamponade should also include an assessment of paradoxical heart rate, which refers to a relative drop in systolic blood pressure of more than 10 mm rt. Art. during inspiration due to collapse of the left ventricle due to the right ventricle. This leads to a curvature of the interventricular septum and increased compression of the left side of the heart with a decrease in filling volumes and a subsequent decrease in stroke volume and systolic arterial pressure.

Although both history and physical examination are critical components of evaluating pericardial effusion and tamponade heart, the standard of care now includes additional methods, such as echocardiography, to confirm diagnosis.

- Analyzes and visualization.

Tests most commonly used to diagnose and evaluate pericardial effusion include:

• Chest X-ray.
• Computed tomography (CT) of the chest.
• MRI of the heart.
• Echocardiogram.
• Pericardiocentesis: A procedure that uses a needle to remove fluid from the pericardium the fluid is then examined to determine the cause of the effusion. Echocardiography is often guided.

Treatment

Treatment for pericardial effusion ranges from cautious waiting to emergency intervention and depends largely on the suspected etiology. Minor effusions without evidence of hemodynamic disturbance are observed by serial echocardiography if considered necessary or if it is determined that they are small enough that there is no need for subsequent observation. For large effusions, diagnostic pericardiocentesis may be performed to assess etiology, or drained to relieve symptoms if the patient has have accompanying symptoms such as shortness of breath, chest discomfort, pulmonary or lower extremity edema, or decreased physical tolerance load. Effusions that have accumulated quickly enough or have grown to such a size that they cause hemodynamic instability or collapse are immediately eliminated. Drainage techniques include needle pericardiocentesis through a subxiphoid or anterior thoracic approach with or without placement pericardial drainage for sequential evacuation, percutaneous balloon pericardiotomy, emergent thoracotomy and pericardiotomy, as well as surgical window of the pericardium through subxiphoid, anterior mini-thoracotomy or video-assisted thoracoscopic access. The choice of the type of intervention depends on the etiology of the pericardial effusion, the clinical condition of the patient at the time of the intervention, and the expected clinical course of the disease.

It should be noted that in patients with extensive pericardial effusion associated with ventricular dysfunction, there is a risk of developing pericardial decompression syndrome (PDS) after pericardiocentesis. Pericardial decompression syndrome (PDS) is an infrequent life-threatening complication following uncomplicated evacuation of pericardial fluid due to cardiac tamponade physiology. SPD is characterized by paradoxical hemodynamic instability and / or pulmonary edema after a simple drainage of the pericardium. Physicians should be familiar with strategies for preventing LRD and offer vulnerable patients a very careful clinical monitoring, especially for those undergoing pericardial drainage for large malignant effusions if suspected tamponade. A smart strategy is not to pump out large amounts of pericardial fluid in one sitting, especially in the case of large pericardial effusions. The most sensible approach would be to remove just enough pericardial fluid to resolve physiology of cardiac tamponade (which can be easily achieved with hemodynamic or echo-Doppler monitoring), and then carry out prolonged drainage of the pericardium to achieve a slow and gradual removal of additional pericardial liquids. Prolonged pericardial drainage can be removed if the daily fluid return is below 30-50 ml.

Forecast

From foreign studies that examined the survival rate of patients with malignant pericardial effusion treated with a subxiphoid pericardial window, there were analyzed medical records of 60 consecutive patients diagnosed with malignant pericardial effusion and treated with pericardial subxiphoid window since 1994 to 2008. 72% had lung cancer. The overall 30-day mortality rate was 31%. The survival rates at 3 months, 6 months, 1 year, and 2 years were 45%, 28%, 17% and 9%, respectively. The overall median survival was 2.6 months. Patients with malignant pericardial effusion, especially those with primary lung cancer, have poor survival rates.