Brian D. Hoit, MD

1. The pericardium is not necessary for life. What does it do? Why is it important?

    The pericardium serves many important but subtle functions. It limits distension and facilitates interaction of the cardiac chambers, influences ventricular filling, prevents excessive torsion and displacement of the heart, minimizes friction with surrounding structures, prevents the spread of infection from contiguous structures, and equalizes gravitational, hydrostatic, and inertial forces over the surface of the heart. The pericardium also has immunologic, vasomotor, fibrinolytic, and metabolic activities. Therapeutically, the pericardial space can be used for drug delivery.

2. What diseases affect the pericardium?

    The pericardium is affected by virtually every category of disease (Box 54-1), including idiopathic, infectious, neoplastic, immune and inflammatory, metabolic, iatrogenic, traumatic, and congenital disease.

3. What is pericarditis? What are the clinical manifestations? What are the causes?

    Acute pericarditis is a syndrome of pericardial inflammation characterized by typical chest pain (sharp, retrosternal pain that radiates to the trapezius ridge, often aggravated by lying down and relieved by sitting up), a pathognomonic pericardial friction rub (characterized as superficial, scratchy, crunchy, and evanescent), and specific electrocardiographic changes (diffuse ST-T wave changes (Fig. 54-1) with characteristic evolutionary changes and PR segment depression). Causes include infection (viral, bacterial, fungal, mycobacterial, or human immunodeficiency virus [HIV] associated), neoplasia (usually metastatic from lung or breast; melanoma, lymphoma, or acute leukemia), myocardial infarction, injury (postpericardiotomy and traumatic), radiation, myxedema, and connective tissue disease.

4. Should patients presenting with acute pericarditis be hospitalized? Why?

    Hospitalization is warranted for high-risk patients with an initial episode of acute pericarditis, in order to determine a cause and to observe for the development of cardiac tamponade; close, early follow-up is critically important for the remainder of patients not hospitalized. Features indicative of high-risk pericarditis include fever greater than 38° C, subacute onset, an immunosuppressed state, trauma, oral anticoagulant therapy, myopericarditis, a moderate or large pericardial effusion, cardiac tamponade, and medical failure.

5. What is the treatment for acute pericarditis?

    Acute pericarditis usually responds to oral nonsteroidal antiinflammatory drugs (NSAIDs), such as aspirin (650 mg every 3 to 4 hours) or ibuprofen (300-800 mg every 6 hours). Colchicine (1 mg/day) may be used to supplement the NSAIDs as it may reduce symptoms and decrease the rate of recurrences. Chest pain is usually alleviated in 1 to 2 days, and the friction rub and ST segment elevation resolve shortly thereafter. Most mild cases of idiopathic and viral pericarditis are adequately treated within a week or two of treatment start, but the duration of therapy is variable and patients should be treated until inflammation or an effusion, if present, has resolved. If colchicine is used, it should be given for 3 months; this is based on the randomized, open label Colchicine for Acute Pericarditis (COPE) trial. The intensity of therapy is dictated by the distress of the patient, and narcotics may be required for severe pain. Corticosteroids should be avoided unless there is a specific indication (such as connective tissue disease or uremic pericarditis) because they enhance viral multiplication and may result in recurrences when the dosage is tapered. Although the European Society of Cardiology (ESC) recently published guidelines for the diagnosis and management of pericardial diseases, there are only a few randomized, placebo-controlled trials from which appropriate therapy may be selected.

6. What is recurrent pericarditis? How is it treated?

    Recurrences of pericarditis (with or without pericardial effusion) occur in up to one-third of patients, usually within 18 months of the acute attack, and may follow a course of many years. Although they may be spontaneous, occurring at varying intervals after discontinuation of drug treatment, they are more commonly associated with either discontinuation or tapering of antiinflammatory drugs. A poor initial response to therapy with NSAIDs and the use of corticosteroids predict recurrences. Two randomized placebo-controlled trials of colchicine for recurrent pericarditis (CORE and Colchicine for Recurrent Pericarditis [CORP] trials) reported marked and significant reductions in symptom persistence at 72 hours and recurrence at 18 months when colchicine was added to conventional therapy. Although painful recurrences of pericarditis may require corticosteroids (preferably at low to moderate doses with slow tapering), once administered, dependency and the development of steroid-induced abnormalities are potential perils. Pericardiectomy should be considered only when repeated attempts at medical treatment have clearly failed.

7. What is post–cardiac injury syndrome?

    Post–cardiac injury syndrome (PCIS) refers to pericarditis or pericardial effusion that results from injury of the pericardium. The principal conditions considered under these headings include post–myocardial infarction syndrome, postpericardiotomy syndrome, and traumatic (blunt, sharp, or iatrogenic) pericarditis. Clinical features include the following:

When the pericardial injury syndrome occurs after an acute myocardial infarction, it is also known as Dressler syndrome, which is now much less common than in the past. In the randomized multicenter Colchicine for the Prevention of Post-Pericardiotomy Syndrome (COPPS) study, prophylactically administered colchicine reduced the incidence of postpericardiotomy syndrome after cardiac surgery.

8. What are the pericardial compressive syndromes? What are their variants?

    The complications of acute pericarditis include cardiac tamponade, constrictive pericarditis, and effusive constrictive pericarditis. Cardiac tamponade is characterized by the accumulation of pericardial fluid under pressure and may be acute, subacute, low pressure (occult), or regional. Constrictive pericarditis is the result of thickening, calcification, and loss of elasticity of the pericardial sac. Pericardial constriction is typically chronic but may be subacute, transient, and occult. Effusive constrictive pericarditis is characterized by constrictive physiology with a coexisting pericardial effusion, usually with tamponade. Elevation of the right atrial and pulmonary wedge pressures persists after drainage of the pericardial fluid.

9. What are similarities between tamponade and constrictive pericarditis?

    Characteristic of both tamponade and constrictive pericarditis is greatly enhanced ventricular interaction (interdependence), in which the hemodynamics of the left and right heart chambers are directly influenced by each other to a much greater degree than normal. Other similarities include diastolic dysfunction and preserved ventricular ejection fraction; increased respiratory variation of ventricular inflow and outflow; equally elevated central venous, pulmonary venous, and ventricular diastolic pressures; and mild pulmonary hypertension.

10. What are the differences between tamponade and constrictive pericarditis?

    In tamponade, the pericardial space is open and transmits the respiratory variation in thoracic pressure to the heart, whereas in constrictive pericarditis, the cavity is obliterated and the pericardium does not transmit these pressure changes. The dissociation of intrathoracic and intracardiac pressures (along with ventricular interaction) is the basis for the physical, hemodynamic, and echocardiographic findings of constriction.

    In tamponade, systemic venous return increases with inspiration, enlarging the right side of the heart and encroaching on the left, whereas in constrictive pericarditis, systemic venous return does not increase with inspiration. The mechanism of diminished left ventricular and increased right ventricular volume in constrictive pericarditis is impaired left ventricular filling because of a lesser pressure gradient from the pulmonary veins.

    In tamponade, early ventricular filling is impaired, whereas it is enhanced in constriction.

11. What are the physical findings of tamponade?

    Cardiac tamponade is a hemodynamic condition characterized by equal elevation of atrial and pericardial pressures, an exaggerated inspiratory decrease in arterial systolic pressure (pulsus paradoxus), and arterial hypotension. The physical findings are dictated by both the severity of cardiac tamponade and the time course of its development. Inspection of the jugular venous pulse waveform reveals elevated venous pressure with a loss of the y descent (because of the decrease in intrapericardial pressure that occurs during ventricular ejection, the systolic atrial filling wave and the x descent are maintained). Pulsus paradoxus is an inspiratory decline of systolic arterial pressure exceeding 10 mm Hg, which is measured by subtracting the pressure at which the Korotkoff sounds are heard only during expiration from the pressure at which sounds are heard throughout the respiratory cycle. Tachycardia and tachypnea are usually present.

12. What are the physical findings of constrictive pericarditis?

    Constrictive pericarditis resembles the congestive states caused by myocardial disease and chronic liver disease. Physical findings include ascites, hepatosplenomegaly, edema, and, in long-standing cases, severe wasting. The venous pressure is elevated and displays deep y and often deep x descents. The venous pressure fails to decrease with inspiration (the Kussmaul sign). A pericardial knock that is similar in timing to the third heart sound is pathognomonic but occurs infrequently. Except in severe cases, the arterial blood pressure is normal.

13. What is the role of echocardiography in tamponade?

    Although tamponade is a clinical diagnosis, echocardiography plays major roles in the identification of pericardial effusion and in the assessment of its hemodynamic significance (Fig. 54-2). The use of echocardiography for the evaluation of all patients with suspected pericardial disease was given a class I recommendation by a 2003 task force of the American College of Cardiology (ACC), the American Heart Association (AHA), and the American Society of Echocardiography (ASE). Except in hyperacute cases, a moderate to large effusion is usually present and swinging of the heart within the effusion may be seen. Reciprocal changes in left and right ventricular volumes occur with respiration. Echocardiographic findings suggesting hemodynamic compromise (atrial and ventricular diastolic collapses) are the result of transiently reversed right atrial and right ventricular diastolic transmural pressures and typically occur before hemodynamic embarrassment. The respiratory variation of mitral and tricuspid flow velocities is greatly increased and out of phase, reflecting the increased ventricular interaction. Less than a 50% inspiratory reduction in the diameter of a dilated inferior vena cava reflects a marked elevation in central venous pressure, and abnormal right-sided venous flows (systolic predominance and expiratory diastolic reversal) are diagnostic. In patients who do not have tamponade on first assessment, repeat echocardiography during clinical follow-up was given a class IIa recommendation by the 2003 ACC/AHA/ASE task force.

14. What is the role of echocardiography in constrictive pericarditis?

    Echocardiography is an essential adjunctive procedure in patients with suspected pericardial constriction. The use of echocardiography for the evaluation of all patients with suspected pericardial disease is a class I recommendation of the ACC/AHA/ASE task force. Echocardiography findings to be sought include increased pericardial thickness (best with transesophageal echocardiography), abrupt inspiratory posterior motion of the ventricular septum in early diastole, plethora of the inferior vena cava and hepatic veins, enlarged atria, and an abnormal contour between the posterior left ventricular the left atrial posterior walls. Although no sign or combination of signs on M-mode is diagnostic of constrictive pericarditis, a normal study virtually rules out the diagnosis. Doppler is particularly useful, showing a high E velocity of right and left ventricular inflow and rapid deceleration, a normal or increased tissue Doppler E′, and a 25% to 40% fall in transmitral flow and marked increase of tricuspid velocity in the first beat after inspiration. Increased respiratory variation of mitral inflow may be missing in patients with markedly elevated left atrial pressure, but may be brought out by preload reduction (e.g., head-up tilt). Hepatic vein flow reversals increase with expiration, reflecting the ventricular interaction and the dissociation of intracardiac and intrathoracic pressures, and pulmonary venous flow shows marked respiratory variation.

15. Are other imaging modalities useful in pericardial disease?

    Other imaging techniques, such as computed tomography (CT) and cardiac magnetic resonance imaging (CMR) are not necessary if two-dimensional and Doppler echocardiography are available. However, pericardial effusion may be detected, quantified, and characterized by CT and CMR. CT scanning of the heart is extremely useful in the diagnosis of constrictive pericarditis; findings include increased pericardial thickness (greater than 4 mm) and calcification. CMR provides direct visualization of the normal pericardium, which is composed of fibrous tissue and has a low magnetic resonance imaging (MRI) signal intensity. CMR is claimed by some to be the diagnostic procedure of choice for the detection of constrictive pericarditis (Fig. 54-3). Late gadolinium enhancement of the pericardium may predict reversibility of transitory constrictive pericarditis (see later) following treatment with antiinflammatory agents.

16. Constrictive pericarditis is a surgical disease, except when very early or in severe, advanced disease. What is the role for medical therapy in constrictive pericarditis?

    Medical therapy of constrictive pericarditis plays a small but important role. Diuretics and digoxin (in the presence of atrial fibrillation) are useful in patients who are not candidates for pericardiectomy because of their high surgical risk. Preoperative diuretics should be used sparingly with the goal of reducing, not eliminating, elevated jugular pressure, edema, and ascites. Postoperatively, diuretics should be given if spontaneous diuresis does not occur; the central venous pressure may take weeks to months to return to normal after pericardiectomy. In some patients, constrictive pericarditis resolves either spontaneously or in response to various combinations of NSAIDs, steroids, and antibiotics (transitory constriction). Therefore, before pericardiectomy is recommended, conservative management for 2 to 3 months in hemodynamically stable patients with subacute constrictive pericarditis is recommended.

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