Pericarditis, the most common pericardial disorder, has many etiologies (Table 61-2), including infectious (viral, bacterial, fungal), metabolic (uremic, drug induced), autoimmune (arthritis, thyroid), postradiation, neoplastic, traumatic, postinfarction (Dressler's syndrome, 10 to 15%), post-pericardiotomy (5 to 30%), and idiopathic (Fig. 61-11). The clinical syndrome for all causes is similar. Chest pain (dull, aching, pressure) or chest tightness is usually present and may be associated with constitutional symptoms (eg, weakness and malaise), fever (occasionally with rigors), and other symptoms such as cough or odynophagia. The pain may be pleuritic, and thus exacerbated by inspiration, cough, or recumbency. These patients therefore often sit up and lean forward for relief. Acute disease may become chronic. The cardinal sign of pericarditis is the pericardial rub, which may be positional and muffled because of an effusion.26
Electrocardiography, chest x-ray, and echocardiography are useful in making the diagnosis. The electrocardiogram may range from normal, to nonspecific ST-segment deviations, to diffuse concave elevation of the ST segments without reciprocal depressions or Q waves. PR-segment depression may be present. Troponin may be elevated with a normal CPK. Ventricular arrhythmias and conduction abnormalities are not commonly seen in pericarditis and are suggestive of an underlying cardiac abnormality if present. Echocardiography may reveal fibrinous thickening of the pericardium with or without a small effusion.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are the mainstay of treatment and may be supplemented with colchicine. Chronic pericardial effusion or constrictive pericarditis may follow acute pericarditis as well as tuberculosis, malignancy, radiation, rheumatoid arthritis, or surgery.26
Infectious pericarditis is most often viral and results from immune complex deposits, direct viral attack, or both. The clinical syndrome involves pain, friction rub, and typical changes on the electrocardiogram. It is often difficult to diagnose and thus labeled as idiopathic disease. Treatment is expectant, and symptoms generally resolve within 2 weeks. Surgical intervention is rarely required.
This is currently an uncommon cause of pericarditis because of availability of effective antibiotic therapy. Microorganisms may invade the pericardial space from contiguous infections in the heart (endocarditis), lung (pneumonia, abscess), subdiaphragmatic space (liver or splenic abscess), or wounds (traumatic or surgical). Hematogenous seeding may also occur, most often in the setting of septicemia and immune compromise.
The most common bacteria implicated in bacterial pericarditis are Haemophilusinfluenzae, meningococci, pneumococci, staphylococci, or streptococci.27 Gram-negative rods, Salmonella and opportunistic sources of infection must be excluded. Regardless of the source or organism, acute suppurative pericarditis is life threatening. A toxic presentation with a high fever is typical with an acute, fulminant clinical course. Purulent pericarditis with tamponade or septicemia may require acute surgical intervention via pericardial window or pericardiectomy and treatment of the inciting cause (eg, removal of foreign body or drainage of abscess) (Fig. 61-12). In adults, pneumopyopericardium is often caused by fistula formation between a hollow viscus and the pericardium. However, invasion from contiguous foci, implantation at the time of surgery or trauma, mediastinitis, endocarditis, and subdiaphragmatic abscess can all induce this condition. Scarring, which results in pericardial constriction, may require pericardiectomy. These patients have an excellent outcome when treated appropriately.27
CT scan showing postoperative anterior mediastinitis with pericardial involvement and left pleural effusion.
Although the incidence of tuberculosis (TB) has significantly declined in industrialized countries, it has increased dramatically in Africa, Asia, and Latin America, accounting for 95% of all cases of active TB. This resurgence in TB reflects the increasing incidence of human immunodeficiency virus (HIV) infection.28 The immune response to the acid-fast bacilli penetrating the pericardium induces a delayed hypersensitivity reaction with lymphokine release and granuloma formation. Complement fixing antibodies initiate cytolysis mediated by antimyolemmal antibodies as the cause of the exudative TB pericarditis.28 The definitive diagnosis is established by examining pericardium or pericardial fluid for mycobacteria.
Four pathologic states are recognized:
Fibrinous exudation, with robust polymorphonuclear infiltration and abundant mycobacteria
Serous or serosanguineous effusions with a mainly lymphocytic exudation and foam cells (Fig. 61-13)
Absorption of effusion, with organization of caseating granulomas, and pericardial thickening caused by fibrin and collagen deposition and fibrosis
Constrictive scarring, often with extensive calcification occurring over a period of years (Fig. 61-14A,B)
CT scan of chronic pericardial thickening and calcification and larger pericardial effusion in a patient with TB.
(A) PA CXR in patient with TB showing calcification of pericardium around LV apex. (B) CT scan of chronic pericardial thickening and calcification in patient with TB.
There is a variable clinical course. Effusion usually develops insidiously with fever, night sweats, fatigue, and weight loss to variable degrees. Children and immunocompromised patients may, however, present with a more fulminant course, often demonstrating both constrictive and tamponade physiology. Despite prompt anti-TB antibiotic treatment, constrictive pericarditis, one of the most severe sequelae, occurs in 30 to 60% of patients. Echocardiography is useful for diagnosing effusive and subacute constrictive TB pericarditis. Standard anti-TB therapy is instituted promptly. Steroids remain controversial, especially in HIV-infected patients. Based on physiology and response to therapy, immediate or interval pericardiectomy is performed to avoid chronic constrictive pericarditis. If calcific pericarditis is present, surgery is undertaken earlier.29
Fungal infection is an uncommon cause of pericarditis. Nocardia, Aspergillus, Candida, and Coccidioides are implicated, with regional specification, in the setting of immunocompromise, debilitation, HIV, severe burns, infancy, or steroid therapy. Candida and Aspergillus generate an insidious clinical picture, which may develop into tamponade or constriction. Fungi such as Histoplasma that tend to be endemic to certain geographic regions may cause pericarditis in young, healthy, immunocompetent patients. This is usually self-limited and resolves within 2 weeks. Similarly, Coccidioides can also infect young healthy individuals in the setting of pneumonia, osteomyelitis, meningitis, or adenopathy. These conditions often resolve either spontaneously or in response to appropriate antifungal regimens. Surgical intervention is not usually required in the acute setting.
Metabolic Causes of Pericarditis
Pericarditis is known to occur in the setting of renal failure, hypothyroidism, autoimmune diseases (such as rheumatoid arthritis), and pharmacotherapy with certain drugs (eg, procainamide and hydralazine).
Uremic pericarditis was first recognized by Bright in 1836.30 Although it is recognized that nitrogen retention (blood urea nitrogen levels are generally >60 mg/dL) is required for uremic pericarditis, the inciting agent is still unknown. The clinical profile typically involves a patient with chronic renal insufficiency who develops pain, fever, and a friction rub.31 There is usually a pericardial fluid collection, which can be exudative or transudative, that is often hemorrhagic. Although the incidence of tamponade is decreasing because of more widespread use of renal replacement therapy,32 it still occurs and remains a primary concern. Initial therapy includes NSAIDs and aggressive dialysis. Pericardial drainage is reserved for hemodynamically significant (tamponade) or refractory effusions (more than 2 weeks despite intensive dialysis), but the latter is the subject of debate.33 Heparin should be administered cautiously, if at all, during dialysis because of the risk of hemorrhagic pericarditis and tamponade.34 Pericardial effusions may also develop in this population because of a variety of conditions such as heart failure, volume overload, and hypoproteinemia. Nonuremic pericarditis is also known to occur in patients on longstanding dialysis.35 Finally, pericardial effusion increases the risk of low-pressure tamponade during dialysis by mechanisms described in the preceding.17
Pericarditis may also occur in the setting of a drug-induced hypersensitivity reaction or lupus-like syndrome.36 Procainamide, hydralazine, isoniazid, methysergide, cromolyn, penicillin, and emetine (among others) have been associated with pericardial inflammation. Minoxidil has been associated with pericardial effusion.37 The clinical presentation and guidelines for management in these settings are similar to those for other types of pericarditis. The inciting agent should be discontinued.
Pericarditis Associated with Rheumatoid Arthritis
Pericarditis is common in patients with rheumatoid arthritis (RA). Approximately half of patients with RA have pericardial effusions, and almost half of all patients with RA have significant pericardial adhesions at autopsy.38 The condition is encountered more often in patients with advanced RA, and is thought to be caused by the higher rheumatoid factor titers often seen with more severe underlying disease. Deposition of immune complexes in the pericardium appears to be the inciting event underlying the inflammatory response.39 The diagnosis is often complicated by the many clinical variants and possible intercurrent diseases such as drug-induced and viral pericarditis. Pericardial drainage is often employed early for symptomatic effusions because response to medical therapy of the underlying RA is slow and unpredictable. Pericardiectomy should be considered in patients with longstanding RA who have developed constriction.40
Severe hypothyroidism produces large, clear, high-protein, high-cholesterol, and high-specific-gravity effusions in 25 to 35% of patients.41 The effusion may precede other signs of hypothyroidism. Clinical tamponade is rare because of the slow accumulation of fluid. However, acute exacerbations owing to acute pericarditis, hemorrhage, or cholesterol pericarditis can induce tamponade.42
Radiation is now the most common etiology of constrictive pericarditis in the United States. This was first recognized in patients who received high-dose mantle radiation for Hodgkin's lymphoma in the 1960s and 1970s and developed cardiac and pericardial pathology, on average 10 to 15 years after therapy. Radiation induces acute pericarditis, pancarditis, and accelerated coronary artery disease in a dose-dependent relationship.43 Patients may present with a combination of pericardial constriction, restrictive cardiomyopathy, valvular heart disease, and coronary artery disease with a predilection for ostial lesions.44 When symptomatic effusions are drained, fluid should be analyzed to clarify the etiology (ie, malignancy versus radiation effect). Constrictive pericarditis can develop several years later and is best treated by pericardiectomy.45
Secondary neoplasms of the pericardium (ie, tumors that involve the pericardium by metastasis or infiltration from adjoining structures) account for greater than 95% of pericardial neoplastic diseases. Primary pericardial tumors are rare, and paraneoplastic effusions can also occur in response to remote tumors.46
The most common secondary tumors involving the pericardium in males (including both metastasis and local extension) are carcinoma of the lung (31.7%) and esophagus (28.7%) and lymphoma (11.9%). In females, carcinoma of the lung (35.9%), lymphoma (17.0%), and carcinoma of the breast (7.5%) are most common. Primary pericardial tumors are very uncommon. Benign tumors are generally encountered in infancy or childhood. Malignant tumors such as mesotheliomas, sarcomas, and angiosarcomas most often present in the third or fourth decade of life.47
In both primary and secondary tumor involvement, the clinical presentation is usually silent, and may be associated with large pericardial effusions. Tamponade can result from hemorrhage into a malignant effusion. Occasionally tumors can induce constriction because of neoplastic tissue, adhesions, or both. The role of surgery is limited to diagnosis and palliation in most of these cases. Large refractory effusions associated with tamponade may need surgical drainage. In such cases, a fluid sample should be submitted to confirm the presence of malignant cells or evaluate for other causes of effusion in patients with cancer because this may influence management.48 In terms of therapeutic benefit, pericardiocentesis has a high failure rate, and subxiphoid drainage or percutaneous balloon pericardiotomy are only transiently effective.49 Although extensive resection and debulking may be necessary in persistent or recurrent malignant pericardial constriction, it has only transient benefit without effective adjunctive chemotherapy and/or radiation therapy. Life expectancy of patients with malignant pericardial involvement averages less than 4 months.50 The surgeon should individualize decisions regarding how aggressively to pursue diagnostic or therapeutic interventions.
Traumatic Pericardial Conditions
Knives, bullets, needles, and intracardiac instrumentation are the most common causes of penetrating trauma to the pericardium and heart. Tamponade is more common in stab wounds than gunshot wounds. The right ventricle is most often involved in anterior chest wounds. Because tamponade provides hemostasis and prevents exsanguination, patients with tamponade have better survival than those with uncontrolled hemorrhage from a penetrating cardiac injury. Diagnosis is often made on clinical grounds supplemented by ultrasonography.51 Stable patients can be explored in the operating theater, but unstable patients should undergo thoracotomy in the emergency department.
Blunt injuries to the heart and pericardium rarely occur in isolation. Trauma owing to compression (including cardiopulmonary resuscitation), blast, and deceleration can produce a spectrum of injuries ranging from cardiac contusion to cardiac rupture and pericardial laceration with herniation or luxation of the heart. Patients with pericardial rupture and cardiac herniation typically have suffered high-energy deceleration trauma and are invariably hypotensive from associated injuries. Hypovolemia may lead to rapid decompensation because cardiac filling becomes increasingly volume dependent in the setting of tamponade. Likewise, patients may initially respond to volume resuscitation. Chest imaging may demonstrate displacement of the heart or presence of free air or intra-abdominal organs within the pericardium. If the heart herniates into the pleura, positioning the patient with the contralateral side down may reduce the herniation. Thoracotomy is required for definitive treatment and repair of associated injuries.52
Acute Postinfarction Pericarditis and Dressler's Syndrome
Postinfarction pericarditis is thought to occur in almost half of patients suffering a transmural myocardial infarction (MI), although it is symptomatic in far fewer. The incidence is decreasing because of more aggressive revascularization in recent decades. Chest pain is almost universally present, and it is important to distinguish the pain of pericarditis from ischemic pain by its positional and pleuritic nature. The pain of early post-MI pericarditis occurs in the first 24 to 72 hours. Dressler's syndrome is a diffuse pleuropericardial inflammation thought to have an autoimmune etiology that occurs weeks to months after infarction. A pericardial rub and effusion may be present but tamponade is rare. In Dressler's syndrome, a pleural rub and effusion may also be present. The electrocardiographic signs of pericarditis may be obscured by those of infarction. Post-MI pericarditis is typically treated with aspirin and/or NSAIDs.53,54 Steroids or colchicine may be used for persistent or recurrent symptoms; however, glucocorticoid use is associated with recurrence of pericarditis.55
Cardiac Surgery and the Pericardium
Postinfarction pericarditis, as described in the preceding, is an important entity for the surgeon to consider in the evaluation of patients with acute coronary syndromes. To the unwary it may masquerade as postinfarction angina and prompt an unnecessarily early operation after myocardial infarction. Extensive fibrinous adhesions and murky gelatinous fluid may be present in the pericardial space and obscure epicardial vessels. When the pericardium is opened late in such a patient, the surgeon should expect dense pericardial adhesions.
Pericardial friction rubs are almost universal after cardiac surgery; some patients develop Dressler's syndrome with pleural and pericardial effusions, pleuritic pain, and generalized malaise. Such patients almost always respond to NSAIDs or a short course of corticosteroids when the symptoms remain refractory.56 Although this condition is benign, it is important (and sometimes difficult) to distinguish between postoperative pericarditis and myocardial ischemia. This distinction can often be made on clinical grounds based on symptoms, hemodynamics, and pattern of ECG changes.57 Echocardiography or angiography may be used in borderline cases to clarify the etiology.
Early postoperative tamponade rarely goes undetected for long because of the high level of vigilance and close hemodynamic monitoring that attend the patient during this time. A vital feature of postoperative tamponade is that a circumferential fluid collection is not required for compromised cardiac function. Hemodynamic deterioration can occur in the setting of localized clot within the pericardium, particularly if it is impinging on the right heart.58 It is also important for surgeons to be aware of the potential for late cardiac tamponade that presents after hospital discharge and often to a clinician other than the cardiac surgeon. This entity is a potentially lethal complication and occurs in 0.5 to 6% of patients after heart surgery, almost exclusively in those on anticoagulation. Late cardiac tamponade (ie, tamponade occurring more than 7 days after cardiac surgery) is more common in younger patients who have undergone isolated valve (as opposed to coronary artery bypass graft) surgery. Patients present on average 3 weeks after surgery, frequently in the setting of an elevated prothrombin time. They are often severely symptomatic, with declining exercise tolerance, dyspnea, an inability to urinate, and sometimes hypotension. Any patient on anticoagulation whose recovery begins an otherwise unexplained decline in this interval should be suspected of having late tamponade and undergo echocardiographic examination. Nearly all patients with late tamponade respond favorably to pericardiocentesis, and are able to safely resume anticoagulation.59
Redo sternotomy may be more hazardous when the heart is adherent to the inner table of the sternum. Closing the pericardium at the time of surgery interposes a protective layer of tissue between the sternum and the heart and may reduce the risks of redo sternotomy. The value of any added protection against cardiac injury on sternal reentry is limited by the relative infrequency of reoperation and the already low incidence of cardiac injury at repeat sternotomy when the pericardium is left open. On the negative side, closing the pericardium can cause kinking of bypass grafts after coronary bypass surgery and may result in hemodynamic compromise caused by cardiac compression.
Several small studies have attempted to answer the question of whether pericardial closure should be performed after cardiac procedures. Rao and associates demonstrated that pericardial closure at the time of cardiac surgery adversely affects postoperative hemodynamics.60 In this ingenious study, the pericardial edges were marked with radiopaque markers and the pericardium was closed with a running suture, the ends of which were exteriorized. After obtaining a postoperative chest film that demonstrated pericardial approximation, a set of baseline hemodynamics was measured. The suture was then removed, another x-ray taken to demonstrate distraction of the pericardial edges, and then the hemodynamic measurements were repeated. Pericardial closure reproducibly resulted in transient, moderate hemodynamic compromise in the first 8 hours after operation (Table 61-3). Although this and other studies have demonstrated adverse short-term hemodynamic consequences of pericardial closure, none have yet reported clinical evidence of worse outcomes.61 Therefore, the risks of pericardial closure must be weighed against its potential benefits and clinical practice should be individualized to the patient.
Table 61-3 Structural and Hemodynamic Changes after Pericardial Closure in Patients Undergoing Elective Isolated Coronary Artery Bypass Grafting ||Download (.pdf)
Table 61-3 Structural and Hemodynamic Changes after Pericardial Closure in Patients Undergoing Elective Isolated Coronary Artery Bypass Grafting
|Parameters Measured||Open Pericardium||Closed Pericardium||p-value|
|Retrosternal space at 1 wk (cm)||13 ± 5||20 ± 7||.0003|
|Retrosternal space at 3 mo (cm)||7 ± 3||14 ± 7||.0001|
|CI L/min/m2 1 h postoperation||3.1 ± 0.8||2.3 ± 0.6||.003 |
|CI L/min/m2 4 h postoperation||3.1 ± 0.9||2.7 ± 0.7||.156 |
|CI L/min/m2 8 h postoperation||3.0 ± 0.8||2.8 ± 0.5||.402 |
|LVSWI g/m/m2 1 h postoperation||72 ± 18||52 ± 13||.002 |
|LVSWI g/m/m2 4 h postoperation||68 ± 17||54 ± 8||.016 |
|LVSWI g/m/m2 8 h postoperation||62 ± 22||52 ± 10||.087 |