Pericarditis overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Pericarditis is a condition in which the sac-like covering surrounding the heart (the pericardium) becomes inflamed. Symptoms of pericarditis include chest pain which increases with deep breathing and lying flat.
Anatomy
The pericardium is a double-walled sac that contains the heart and the roots of the great vessels. Morphologically, it is a conical-shaped, double-walled fibro-serous membrane. It rests posteriorly to the sternum at the level of second to sixth costal cartilages and T5-T8 vertebrae.
Classification
Pericarditis can be classified according to the composition of the inflammatory exudate or the composition of the fluid that accumulates around the heart. It can also be classified into "acute" and "chronic" forms, depending on the timing of presentation and duration.
Pathophysiology
Pericarditis is inflammation of the pericardium, the double-walled sac that contains the heart and the roots of the great vessels. There can be an accompanying accumulation of fluid that can be either serous (free flowing fluid) or fibrinous (an exudate, which is a thick fluid composed of proteins, fibrin strands, inflammatory cells, cell breakdown products, and sometimes bacteria). Vascular congestion of the pericardium is also present. The underlying myocardium may or may not be inflamed as well. If the myocardium is involved in the inflammatory process, then this is called myopericarditis, and the CK and troponin may be elevated.
Causes
Pericarditis is usually a complication of viral infections, most commonly echovirus or coxsackie virus. In addition, pericarditis can be associated with diseases such as autoimmune disorders, cancer, hypothyroidism, and kidney failure. Often the cause of pericarditis remains unknown, or idiopathic.
Differentiating Pericarditis from other Diseases
Signs and symptoms of pericarditis may be similar to several other conditions including myocardial infarction, aortic dissection and pulmonary embolism which are life threatening and therefore it is important to differentiate them. Pain along the trapezius ridge, which is unresponsive to vasodilator therapy and varies with position are signs specific for pericarditis.
Epidemiology and Demographics
Pericarditis most often affects men aged 20 - 50. It usually follows respiratory infections. Pericarditis in developed countries are usually due to viral infections such as echovirus and coxsackie virus, while in developing countries it is usually secondary to tuberculosis or HIV infection. The incidence of pericarditis following MI has greatly reduced with the use of early thrombolytic agents and revascularization.
Natural History, Complications and Prognosis
Pericarditis is often self-limited and most people recover in 2 weeks to 3 months. However, the condition can be complicated by significant fluid buildup around the heart (a pericardial effusion or cardiac tamponade) and may require urgent intervention including pericardiocentesis. If scarring of the sac around the heart (the pericardium) occurs, then this is called constrictive pericarditis which may require surgical stripping of the scar.
Diagnosis
History and Symptoms
Patients with pericarditis commonly present with chest pain that changes with position, cough, fever, breathlessness, and fatigue.
Physical Examination
A careful physical examination must be performed to exclude the presence of cardiac tamponade, a dangerous complication of pericarditis. If cardiac tamponade is present, then pulsus paradoxus, hypotension, an elevated jugular venous pressure and peripheral edema may be present.
Laboratory Findings
Non-specific markers of inflammation are generally elevated in pericarditis. These include the leukocyte count, C-reactive protein, and ESR. The cardiac troponin is elevated if there is an injury to the underlying myocardium, a condition termed as myopericarditis. Diagnostic pericardiocentesis and biopsy help in identifying an underlying infectious or malignant process.Non-specific markers of inflammation are generally elevated in pericarditis. These include the leukocyte count, C-reactive protein, and ESR. The cardiac troponin is elevated if there is an injury to the underlying myocardium, a condition termed as myopericarditis. Diagnostic pericardiocentesis and biopsy help in identifying an underlying infectious or malignant process.
EKG
In the presence of a large effusion or tamponade, there may be diminished voltage and electrical alternans (alternation of QRS complex amplitude or axis between beats).
Chest X-ray
A flask-shaped, enlarged cardiac silhouette will be observed on chest x-ray in pericarditis complicated with pericardial effusion or tamponade. A mass may also be seen when malignancy is the cause. Calcification of pericardium may be noted in constrictive pericarditis.
CT
On CT, pericardial fluid adds to the thickness of pericardium as both have the similar signal intensities. In pericarditis, pericardium can generate an intermediate signal intensity and may enhance after gadolinium administration. In pericardial effusion, hemorrhagic effusions can be differentiated from a transudate or an exudate based on signal characteristics (high signal on T1-weighted images) or density (high-density clot on CT). CT is superior to MRI in the visualization of pericardial calcification which is often seen in the patient with pericardial constriction. CT imaging also helps in detecting the presence of tumors and the extent of metastasis of the neoplasm.
MRI
On MRI, normal pericardium appears as a thin dark band that is bordered by a bright band on both sides on T1 weighted spin imaging. These surrounding bright bands are associated with the surrounding epicardial and pericardial fat. Following the administration of gadolinium, pericardium may appear thick and inflamed in the setting of pericarditis. Lower intensity signal is observed in constrictive pericarditis than in acute pericarditis. Comprehensive visualization of the LV endocardium and the physiologic consequences of abnormal pericardial thickening can also be obtained without exposure to ionizing radiation.[1]
Echocardiography
Echocardiography is generally performed to assess for the presence of a pericardial effusion and to assess and monitor its size. Echocardiography is critical in confirming the clinical suspicion cardiac tamponade.
Treatment
Medical Therapy
The management of pericarditis depends upon whether the patient has an uncomplicated or a complicated disease course. Uncomplicated pericarditis is generally treated with non-steroidal anti-inflammatory drugs such as ibuprofen in case of viral or idiopathic pericarditis and aspirin in case of post-MI pericarditis.Pericarditis complicated with effusion or cardiac tamponade is generally treated with urgent pericardiocentesis in case of cardiac tamponade, antibiotics in case of purulent pericardial effusion, and steroids or colchicine in patients with recurrent or refractory disease.
Surgery
Pericardiocentesis
Percutaneous pericardiocentesis is a procedure where fluid is aspirated from the pericardium (the sac enveloping the heart) using a needle via a percutaneous approach. Pericardiocentesis can provide a diagnostic sampling of pericardial fluid and can be used as a therapeutic maneuver to evacuate pericardial fluid and lower the pericardial pressure.
Pericardial Window
Creation of a pericardial window is a cardiac surgical procedure in which an opening is made in the pericardium to drain fluid that has accumulated around the heart by creating a fistula or "window" from the pericardial space to the peritoneal cavity. Flow of fluid into the peritoneal cavity prevents the accumulation of fluid around the heart (a pericardial effusion), which might cause compression and impaired filling of the heart (cardiac tamponade), a dangerous complication.[2] The procedure is performed for both diagnostic and therapeutic purposes. The creation of a pericardial window is usually performed by a cardiac surgeon or thoracic surgeon who makes an incision, commonly sub-xiphoid, and cuts a small hole in the pericardium. This surgery is performed with local anesthesia. An incision is made either below the sternum, or alternately between the ribs of the left chest. The resection can be with scissors, cautery, a stapling device, or a harmonic scalpel, with no one technique demonstrably better than another. It is best to have a combination of techniques available to resect the pericardium adequately. The surgeon may place a catheter in the pericardial window so that fluid can continue to drain for a short period of time after the surgery. Chest tubes are removed in 2-3 days once the drainage is less than 200cc/24hrs.
Pericardial Stripping
Pericardiectomy is the surgical removal of part or most of the pericardium. This operation is performed to relieve constrictive pericarditis or to remove a pericardium that is calcified and fibrous. Constrictive pericarditis is a progressive disease without spontaneous reversal of pericardial thickening. Some patients can be medically managed for several years. Edema can be controlled with diuretics and slowing the heart rate can maximize the diastolic filling time. Many patients eventually develop significant debility from impaired cardiac output and elevated right and left sided filling pressures. The definitive treatment for constrictive pericarditis is pericardiectomy which is also known as pericardial stripping. This is a surgical procedure where the entire pericardium is peeled away from the heart. Due to the significant risks involved with pericardial stripping, many patients are treated medically, with judicious use of diuretics.
References
- ↑ Hatle LK, Appleton CP, Popp RL (1989). "Differentiation of constrictive pericarditis and restrictive cardiomyopathy by Doppler echocardiography". Circulation. 79 (2): 357–70. PMID 2914352.
- ↑ Stuart J. Hutchison (10 December 2008). Pericardial diseases: clinical diagnostic imaging atlas. Elsevier Health Sciences. pp. 93–. ISBN 9781416052746. Retrieved 10 November 2010.