Understanding Pericarditis: Causes, Symptoms, and Treatments

Picture of the heart in the pericardial sac

Theheartmuscle has a tight covering that surrounds it, a lining sac called the pericardium (peri=around+cardium=heart). This sac actually has two layers. The visceral pericardium is only one cell layer thick and fits tightly onto the heart muscle. The parietal pericardium is much tougher and thicker and has fibers that tether the heart to the rib cage anddiaphragm. There is a potential space between the layers, meaning that in normal situations, it has a minimal amount of fluid. However, should inflammation occur, it can fill with fluid. Inflammation of the lining of the heart is calledpericarditis(itis=inflammation).

Things to know about pericarditis

• Pericarditis is an inflammation of the lining surrounding the heart (thepericardial sac).
• Pericardial effusionis a collection of fluid in thepericardialsac. This fluid may be produced by inflammation.
• The cause of pericarditis in most individuals is unknown but is likely due to viral infection. Pericarditis may be an associated complication of many diseases or may be due totrauma.
• The diagnosis of pericarditis is made by history and physical examination. Testing usually includes anelectrocardiogram(EKG,ECG),chest X-ray,echocardiogram, orultrasound of the heart. The inflammation of pericarditis is usually treated with anti-inflammatory medications (such asibuprofen). It is important to treat the underlying disease or illness if one is present.
• Pericardial tamponade occurs when enough fluid accumulates in the sac to compromise the heart's ability to adequately pump blood.
• Tamponade is a medical emergency and is treated by pericardiocentesis, inserting a needle into the pericardial sac to remove the fluid.
• While pericarditis is a relatively rare complication ofCOVID-19, studies have shown that it can occur in some people infected with the virus.

Pericarditis is usually from unknown causes (idiopathic). The cause may often be viral infections. Causes of pericarditis include:

Infections:

• Viruses(likecold,flu, orCoxsackie virus)
• Bacteria (liketuberculosisorpneumonia)
• Fungal infections(likehistoplasmosis)
• HIV(human immunodeficiency virus)

Inflammatory diseases:

Diseases that can cause generalized inflammation in other places within the body can also cause inflammation of the pericardium. Some examples include:

• Rheumatoid arthritis
• Systemic lupus erythematosus(SLE)
• Scleroderma
• Ankylosing spondylitis
• Inflammatory bowel disease

Metabolic illnesses:

• Kidney failureanduremia
• Hypothyroidism

心disease:

• 心脏病can cause direct irritation and inflammation of the pericardial lining.
• Dressler's syndrome describes inflammation caused by an immune response to heart tissue damage from a heart attack,open heart surgery, or trauma.

Other causes:

• Tumors andcancers: Some types ofcancersuch aslung cancer
• 放射治疗
• Medications: Certain medications such ashydralazineandprocainamide, can cause pericarditis as a side effect.

In most cases, pericarditis is a self-limiting condition that resolves within a few weeks with appropriate treatment. However, in some cases, pericarditis can lead to complications, such as pericardial effusion (accumulation of fluid in the pericardial sac) or cardiac tamponade (compression of the heart due to the accumulation of fluid or blood in the pericardial sac), which can be life-threatening if left untreated. The symptoms of pericarditis can range from mild to severe, includingchest pain,fever,fatigue, andshortness of breath.

Chest painis the most common symptom of pericarditis.

• Classically, thepainbegins in the center of the chest and radiates to the neck or upper back.
• Thepainis sharp and stabbing, but may also be felt as a dull ache or burning pain.
• 强度可能是轻微或严重can come on gradually or suddenly.
• The pain makes it hurt to take a breath.
• Most individuals feel worse when lying flat.

Other symptoms may includefeversandchills, sweats, shortness of breath, anddifficulty swallowing.

When pericarditis is due to infection, the symptoms tend to arise quickly. Inflammation due to chronic diseases is more gradual in onset.

History and physical examination

The diagnosis of pericarditis begins with the health care professional taking a history of the pain and its character. The health care professional will perform a physical examination and ask the patient about associated symptoms. Past medical history is important since pericarditis can be a complication of a chronic disease or a side effect of medication.

The most common physical finding that helps confirm the diagnosis of pericarditis is a pericardial friction rub. Inflammation prevents the two layers of pericardium from easily sliding against each other with each heartbeat. The inflammation causes a friction noise that can be heard with a stethoscope when listening to the heart. It is better heard when the patient leans forward, which causes the heart to shift to the front of the chest. The rub may not always be present and may come and go from hour to hour.

Diagnostic testing

The electrocardiogram (EKG or ECG) shows the electrical activity of the heart. In pericarditis, there are hallmark changes that are seen and can help make the diagnosis. While an abnormal EKG is helpful in making the diagnosis, in the early stages of inflammation, the EKG may be normal. In most cases of uncomplicated pericarditis, a chest X-ray is usually normal. However, if fluid accumulates in the pericardial sac, the heart can appear larger on the X-ray.

A sound wave test of the heart (an echocardiogram orultrasoundof the heart) is very helpful in detecting and quantifying the fluid in pericarditis. The purpose of the test is to detect an accumulation of fluid in the pericardial sac, called an effusion. Although in many mild cases of acute pericarditis, there is no pericardial fluid seen withechocardiography. A variety of blood tests may be ordered depending on the clinical situation.

Pericardiocentesis, a procedure using a needle, is used to draw fluid out of the pericardial sac. It may be done to detect bacterial infection. This procedure can also be used to treat dangerous, severe pericarditis called pericardial tamponade.

Most often, pericarditis is caused by a viral infection and the treatment is aimed at decreasing inflammation and controlling pain.

• Nonsteroidal anti-inflammatorydrugsorNSAIDs(ibuprofen [Motrinand others],naproxen[Aleve,Naprosyn, and others]) are commonly used. A short course of narcotic pain medication may be helpful. For other causes of pericarditis, treatment of the underlying cause of pericarditis is essential.
• Pericardiocentesis, a procedure where a thin needle is inserted through the chest wall into the pericardial sac, may be considered if a large effusion is present that affectsheart function(see cardiac tamponade below).
• Pericardotomy (cutting a hole in the pericardial sac) or pericardectomy (removing the sac completely) may be needed for recurrent pericarditis that causes scarring within the pericardial sac and prevents the heart from beating properly.

Cardiac tamponade

If enough fluid accumulates in the pericardial sac, it can affect heart function and decreaseblood pressure. The fluid can accumulate gradually over time or can gather rapidly, depending on the cause. The increased amount of fluid can cause a rise in pressure within the pericardial sac. This causes two potential problems:

• The ventricles or lower chambers of the heart responsible for pumping blood to the body have difficulty filling with blood because the fluid in the sac prevents them from filling with blood. That means there is less blood to send to the body with each heartbeat.
• The increased pressure within the pericardium may decrease the amount of blood that can return to the heart. The less blood that returns means there is less to pump out with the next heartbeat.

If a disease causes the pericardial effusion to increase in size slowly, symptoms may come on gradually and the heart can adapt. The symptoms may be nonspecific but can include shortness of breath and difficulty withexerciseor doing daily activities. But if the fluid accumulates quickly, like bleeding because of trauma, small amounts of fluid can cause significant problems.

Cardiac tamponade is a medical emergency and the patient may be inshock与low blood pressure,困难breathing, andcongestive heart failure. The classic findings of cardiac tamponade are:

• low blood pressure;
• distended veins in the neck (jugular vein bulging); and
• muffled heart tones using a stethoscope.

Testing requires emergent EKG, portable chest X-ray, and echocardiogram. Some hospitals are not staffed 24 hours a day by a cardiologist or with an echocardiogram and the diagnosis is often made clinically.

Cardiac tamponade is a true medical emergency that requires pericardiocentesis, a procedure where a long needle is inserted through the chest wall into the pericardial sac and the fluid is removed. This relieves the pressure within the sac and temporarily resolves the acute emergency. Aplastictube or catheter may be left in the chest until the underlying illness that caused the tamponade is treated and stabilized.

Constrictive pericarditis

Recurrent inflammation of the pericardial sac can lead to scarring of the space between the two layers of the pericardial sac. The scarring constricts the movement of the heart during each heartbeat and can prevent the heart from expanding to accept blood returning from the body after each heartbeat. This affects heart function and cardiac output because with less blood returning with each beat, there is less that can be pumped out with the next heartbeat.

Bleeding into the pericardium from trauma or from a heart operation is the most common cause ofconstrictive pericarditis, but tumors, or infections liketuberculosisor fungus, can also be the cause.

The constriction occurs slowly over time and will cause shortness of breath on exertion and decreased ability toexercise. Swelling in the legs and the abdomen may exist because it is difficult for blood to return to the heart, and the back pressure in the veins causes fluid to leak out into the tissues.

Diagnosis is made again by history, physical examination, EKG, echocardiography, and sometimescomputerized tomography(CT) of the chest.

If there is significant scarring of the pericardial sac, pericardiotomy -- an operation to split open the pericardium to free up the constriction -- may be required to improve function. If the whole pericardium must be stripped away from the heart muscle, the procedure is called a pericardectomy.