Pericardial and Myocardial Disease

Pericardial Disease (Pericarditis)

Our knowledge of pericardial function and disease has increased greatly since Hippocrates described the pericardium in 460 BC as “a smooth tunic that envelops the heart and contains a small amount of fluid resembling urine.” Galen provided the first description of a pericardial effusion and performed the first pericardial resection.¹ Lancisi first described the appearance of constrictive pericarditis at autopsy in 1728. Also in the 18th century, Laennec said, “There are few diseases attended by more variable symptoms and more difficult to diagnose than [pericarditis].”¹ In 1935, Beck described the clinical presentation of cardiac tamponade, known as Beck‘s triad (hypotension, jugular venous distention, and muffled heart sounds).² Despite the passage of time and the modern availability of many diagnostic tools, the diagnosis and treatment of pericardial disease still present a challenge.

Etiology

Each of the disorders listed in Box 82-1 can produce acute pericarditis, with or without pericardial effusion. In addition, most of these disorders can progress to cardiac tamponade or constrictive pericarditis.

BOX 82-1 Etiology of Pericarditis

• Myocardial infarction

• Rheumatoid arthritis

• Systemic lupus erythematosus

Most cases of pericarditis in developed countries are idiopathic. Even exhaustive clinical testing identifies a specific cause in less than 20% of patients, with the remainder being idiopathic despite often being putatively of viral cause.

Clinical Features and Diagnostic Strategies

Patients with uremic pericarditis have chest pain, unexplained fever, and possibly a coarse friction rub. They also may have significant effusions. The ECG in uremic pericarditis is often normal because little epicardial inflammation occurs.⁷ In a dialysis patient, cardiac enlargement on chest radiograph in the absence of signs of volume overload or congestive heart failure (CHF) should prompt consideration of pericardial effusion. An echocardiogram will provide the definitive answer. Pericardiocentesis may be needed to exclude infection.

Management and Disposition

Uremic pericarditis is initially treated with intensive dialysis. NSAIDs are ineffective and often are contraindicated by the patient’s underlying renal impairment. Systemic steroids (prednisone 1 mg/kg daily) may require 1 or 2 weeks of therapy in the few patients who do not respond to dialysis.

Complications

Uremic pericardial effusions are among the most common causes of cardiac tamponade. Uremic pericardial effusions may be locular and difficult to fully drain with a catheter, and surgical options should be considered.

Post–Myocardial Infarction Pericarditis

Approximately 20% of patients with transmural MIs experience a different quality of chest pain 2 to 4 days after infarction. This pain may represent early post-MI pericarditis. There is frequently low-grade fever and a transient pericardial friction rub. A large pericardial effusion is unusual. Early post-MI pericarditis is generally short-lived and disappears with 1 to 3 days with aspirin therapy (325 mg/day).

The ECG changes of pericarditis usually are masked by the acute MI changes. Patients with early post-MI pericarditis have more dysrhythmias and heart failure. Pericarditis in acute MI may be an indicator of greater myocardial damage and a worse outcome.

Dressler reported a syndrome of fever, pleuritis, leukocytosis, pericardial friction rub, and chest radiograph evidence of new pericardial or pleural effusions in post-MI patients.⁸ Frequent relapses and a high incidence of friction rubs led Dressler to describe this syndrome as a delayed complication of MI in contrast to the well-known syndrome of early post-MI pericarditis. The cause of late post-MI pericarditis (Dressler’s syndrome) may be immunologic, but the syndrome may also occur with pulmonary embolus and after pericardiotomy. Anticoagulants should be discontinued to reduce the risk of hemorrhage. Delayed post-MI pericarditis is treated with NSAIDs such as ibuprofen 600 mg four times per day or indomethacin 25 mg three times per day.

Postinjury Pericarditis

Perspective

Postcardiac injury syndrome is defined as pericarditis after MI, cardiac surgery, or trauma. The incidence ranges from approximately 5% after MI to 30% after thoracic surgery or trauma. Pericarditis develops in 20% of patients with a penetrating cardiac injury, few of whom have cardiac tamponade. It can also occur after chest trauma that does not involve the heart or pericardium.

Principles of Disease

Injury to the pericardium in blunt trauma may range from contusion to laceration or rupture. Some degree of traumatic pericarditis is found during surgery or at autopsy in many patients sustaining severe blunt trauma of the chest.

Penetrating wounds to the heart usually cause laceration of the pericardium and the myocardium, with secondary pericarditis and pericardial infections. Although the exact incidence is unknown, infection, tamponade, myocarditis, and inflammatory pericarditis may occur.

An immune pathogenesis is suggested by the development of cardiac autoantibodies, although these autoantibodies are common after injury, even in patients who do not develop pericarditis. Constrictive pericarditis occurs secondary to trauma. This may be caused by pericardial blood, possibly secondary to the decreased resorptive power of damaged pericardium, with secondary fibrosis and constriction.

Clinical Features

Symptoms and signs of postcardiac injury syndrome include pericardial rub, fever, and chest pain. Although the diagnosis is usually established clinically, confirmation by echocardiography is helpful. The interval between injury and the onset of pericarditis ranges from 4 to 12 days. During hospitalization, purulent pericarditis should be considered as a possible source of febrile illness in a trauma patient with multisystem organ failure.

Management and Disposition

Most patients respond to aspirin (325 mg daily) or NSAIDs (ibuprofen 600 mg four times per day). Uncomplicated pericarditis secondary to blunt trauma usually resolves. The patient should be observed until other life-threatening disease processes have been excluded.

Neoplastic Pericardial Disease

Perspective

Malignant pericardial tumors typically manifest late, which complicates diagnosis and treatment. Malignant involvement of the pericardium is observed in 3.4% of general autopsies and 2 to 31% of cancer autopsies. The most common causes are lung cancer (30%), breast cancer (23%), lymphoma (17%) and leukemia (9%). Primary malignancies of the pericardium are rare.⁹

Principles of Disease and Pathophysiology

The pattern of cardiac involvement by a malignant tumor is determined by the heart’s lymphatic drainage system.

Malignant pericardial effusions contribute directly to the patient’s death in most cases commonly from cardiac tamponade. Although the underlying disease process is often advanced when tamponade develops, the patient’s quality of life can usually be improved if tamponade is treated promptly.

Clinical Features

Primary cardiac neoplasms, such as angiosarcoma and teratoma, can initially cause symptoms consistent with pericarditis. The typical course is that of an acute pericarditis that resolves and subsequently recurs. Malignant pericardial disease is difficult to diagnose. Most patients are asymptomatic or have nonspecific symptoms, such as shortness of breath, cough, palpitations, ill-defined chest pain, weakness, dizziness, hiccups, or fatigue.

Diagnostic Strategies

The diagnostic workup for malignant pericardial effusion includes an echocardiogram, computed tomography (CT), or magnetic resonance imaging (MRI). When a pericardial effusion is identified, pericardial fluid cytology is recommended if the underlying malignancy is undiagnosed.

Management and Disposition

Malignant pericardial effusion treatment may include pericardiocentesis, local instillation of sclerosing or chemotherapeutic agents, systemic chemotherapy, cardiac radiation, and pericardial window. The method chosen depends on the primary tumor and the patient’s expected length of survival.

The prognosis for patients with malignant pericardial disease depends on the type and extent of the underlying cancer.

Radiation-Induced Pericarditis

Fewer than 5% of patients treated with radiation therapy develop pericarditis. The incidence has decreased with improved radiation therapy techniques. The percentage of pericardial volume irradiated and the dosage determine which patients develop pericarditis. Radiation-induced pericarditis is seen most commonly in patients with Hodgkin’s lymphoma or breast cancer. Pericardial effusion and constrictive pericarditis are common, and tumor recurrence should be considered.

Pericardial Disease Related to Connective Tissue Disorders

Pericarditis occurs in approximately one third of patients with rheumatoid arthritis (RA), usually within 3 years of the initial diagnosis. Rheumatoid pericardial disease is rarely clinically significant. Occasional patients develop effusions, constrictive pericarditis, or cardiac tamponade. These patients usually have rheumatoid nodules, elevated circulating rheumatoid factor levels, and valvular heart disease. Pericardial fluid may have rheumatoid factor or a low glucose level. Corticosteroid treatment is useful. Prednisone 1 mg/kg/day is the initial treatment, with close follow-up appointment.

Pericarditis is found at autopsy in more than 50% of patients with systemic lupus erythematosus (SLE). The effusion is usually thick and fibrinous. Either cardiac tamponade or constrictive pericarditis may develop. Lupus erythematosus cells may be identified in pericardial fluid specimens. Corticosteroid therapy is indicated.

Other connective tissue diseases that may cause pericarditis include Sjögren’s syndrome, giant cell arteritis, ankylosing spondylitis, Reiter’s syndrome, Behçet’s disease, systemic sclerosis, and polyarteritis nodosa.

Miscellaneous Infectious Causes of Pericarditis

Other causes of pericarditis include Rickettsia conorii, which causes Mediterranean spotted fever (treated with doxycycline), Mycoplasma pneumoniae (treated with a macrolide), Nocardia asteroides (treated with pericardiectomy and long-term use of antibiotics such as sulfisoxazole), Chlamydia trachomatis, Epstein-Barr virus, cytomegalovirus infection, Haemophilus actinomycetemcomitans (treated with chloramphenicol), and coccidioidomycosis (endemic in the southwestern United States). Viral and bacterial causes of pericarditis can coexist, such as varicella-zoster infection superinfected with Staphylococcus aureus. These bacterial superinfections associated with varicella are more common in children.

Pericardial Effusion

Etiology and Clinical Features

The most common causes of pericardial effusion are viral or idiopathic pericarditis, malignancy, uremia, trauma, and radiation therapy. Drug reactions and autoimmune diseases are less common causes.

Pericardial effusion is often asymptomatic. Patients with known associated conditions (e.g., cancer or renal failure) with cough, fever, chest pain, or dyspnea may have an effusion.

Diagnostic Strategies

Pericardial effusion may cause an enlarged cardiac silhouette on chest radiograph, usually with normal pulmonary vasculature. A minimum of 200 to 250 mL of pericardial fluid is necessary to produce cardiomegaly on a chest radiograph.

Echocardiography is the diagnostic modality of choice (Fig. 82-2). It easily differentiates pericardial fluid from cardiac chamber enlargement and provides information about myocardial wall motion.

Figure 82-2 A, Bedside ultrasound showing a pericardial effusion. The effusion is best seen superior to the left ventricle at the top of the image. B, The proper technique for emergency department ultrasound of pericardial effusion. (Courtesy Jessica Resnick, MD.)

CT may be useful in diagnosing pericardial effusion when the echocardiogram is technically unsatisfactory. MRI can also be diagnostic. Nuclear scans may be useful in detecting purulent pericardial effusions.

Pericardiocentesis may be performed for either diagnostic or therapeutic purposes. Elective diagnostic pericardiocentesis is indicated in cancer patients (to differentiate malignant effusion from postradiation pericarditis), for failure to respond to usual treatment, or when bacterial infection is suspected. Common complications of pericardiocentesis include induction of cardiac dysrhythmias, pneumothorax, perforation of myocardium, laceration of coronary or internal mammary arteries, and liver laceration. Echocardiographic-guided pericardiocentesis is the procedure of choice.

Pericardial fluid should be analyzed for protein, glucose, specific gravity, cell count and differential, Gram’s stain, and culture. Other tests, depending on the clinical picture, include cytology, acid-fast stain, fungal smear, and connective tissue disease screening.

The gross appearance of the pericardial fluid provides a clue to the cause. Serosanguineous effusions are associated most commonly with neoplasms, tuberculosis, uremia, radiation, and idiopathic pericarditis. Grossly bloody effusions are caused by blunt or penetrating trauma, postinfarction myocardial rupture, aortic dissection, coagulopathies, and iatrogenic cardiac perforation. Purulent pericardial fluid is seen with pneumonia, empyema, and sepsis.

Cardiac Tamponade

Etiology and Pathophysiology

Ten percent of all patients with cancer develop cardiac tamponade.¹⁰ Cardiac tamponade should be suspected in patients with penetrating chest wounds. It is also common in patients with uremic pericarditis.

Cardiac tamponade is the result of compression of the myocardium by the contents of the pericardium. This compression is usually caused by fluid, but it may be caused by gas, pus, blood, or a combination of factors.

Cardiac tamponade is a physiologic continuum reflecting the amount of fluid, the rate of accumulation, and the nature of the heart. The three stages necessary for tamponade to develop are fluid filling the recesses of the parietal pericardium, fluid accumulating faster than the rate of the parietal pericardium’s ability to stretch, and accumulation that exceeds the body’s ability to increase blood volume to support right ventricle filling pressure. The final result is increased pericardial pressure, which causes decreased ventricle compliance and decreased flow of blood into the heart. The reduction of blood inflow into the right ventricle results in decreased stroke volume that leads to decreased cardiac output.¹⁰ The most important factor in the development of tamponade is the rate of fluid accumulation.

The heart initially responds to tamponade by increasing heart rate to maintain cardiac output. This compensatory mechanism is maintained until late in the clinical course, followed by decompensation.

Symptoms and Signs

Cardiac tamponade symptoms are often nonspecific, but particularly include chest pain, cough, or dyspnea, any of which may be progressive and severe. The classic triad of cardiac tamponade signs described by Beck is hypotension, distended neck veins, and muffled heart sounds.¹¹ These signs may not be present if tamponade develops quickly.

Diagnostic Strategies

The chest radiograph shows cardiomegaly only if there is a large accumulation of fluid (250 mL). The ECG classically shows decreased voltage or electrical alternans (Fig. 82-3), but the latter is rare. Echocardiography confirms the diagnosis when an effusion and paradoxical systolic wall motion are seen. Thermodilution catheters can also be diagnostic, showing equalization of right and left ventricular pressures.

Figure 82-3 Electrocardiogram showing electrical alternans.

Management and Prognosis

Initial treatment includes volume augmentation to the right ventricle with intravenous fluids to increase the filling pressure to overcome the pericardial constriction. Pericardiocentesis or pericardial window is the treatment of choice. Enough fluid should be withdrawn to stabilize the patient. If tamponade recurs, pericardiocentesis may be repeated, or a drainage catheter may be left in the pericardial space. A pericardiectomy ultimately may be necessary. Cardiac tamponade has a high mortality that depends on the severity and nature of the underlying disease, the time course of onset, and the rapidity of diagnosis and intervention. Traumatic cardiac tamponade is discussed in Chapter 45.

Purulent Pericarditis

Epidemiology and Etiology

Purulent pericarditis is a life-threatening process that is seen most commonly in a hospitalized patient with systemic illnesses who develops sepsis. It can occur in any age group and can be caused by any type of infectious agent, with bacteria, especially Streptococcus and Staphylococcus, being the most common. Candida pericarditis is found after cardiac surgery or in patients with impaired host defenses or severe debilitating underlying diseases. Histoplasma infection of the pericardium occurs in endemic areas, including the Ohio and Mississippi River valleys.

Principles of Disease and Pathophysiology

Purulent pericarditis occurs by several mechanisms: (1) spread from an adjacent infection, such as pneumonia or empyema; (2) hematogenous spread from a distant site; (3) direct inoculation of bacteria (trauma or procedure); and (4) spread from an intracardiac source. The most common mechanism is spread from a distant site.

Clinical Features and Diagnostic Strategies

Purulent pericarditis usually manifests as a febrile illness lasting 2 or 3 days. Common presenting signs include tachycardia, dyspnea, hepatomegaly, elevated central venous pressure, chest pain, friction rub, and leukocytosis. The most common presentation is a hospitalized patient with a serious underlying disease who initially improves after treatment of the primary process but later develops fever, dyspnea, and chest pain.

The diagnosis should be suspected in any febrile patient with multisystem illness who has a pericardial effusion. Pericardiocentesis is necessary to establish the diagnosis, obtain fluid for microbiologic studies, and relieve cardiac tamponade.

Management and Disposition

Pericardiectomy is the traditional treatment of choice. Indwelling catheters, coupled with lavage, antibiotics (such as vancomycin 1 g two times per day or ampicillin-sulbactam 3 g four times a day), and fibrinolytics, may avoid the need for surgery. Intravenous antibiotics or antifungals are also needed.

The overall survival rate for purulent pericarditis is approximately 30% with antibiotic therapy alone and 50% when combined with early surgical drainage. In addition to the initial complications related to sepsis and tamponade, long-term sequelae of purulent pericarditis include the development of constrictive pericarditis.

Tuberculous Pericarditis

Tuberculous pericarditis is estimated to occur in 1 or 2% of patients with pulmonary tuberculosis.¹² In Africa, it is the most common cause of pericarditis. In countries in which tuberculosis is not a major health problem, tuberculous pericarditis is most common in patients who are socioeconomically deprived or immunodeficient. In many patients the chest radiograph shows an enlarged cardiac silhouette without a pulmonary infiltrate. Pericardial fluid aspirates reveal acid-fast bacilli by smear or culture (which may require 4-6 weeks to become positive) in approximately 50% of cases. Diagnostic workup should include assessment for human immunodeficiency virus (HIV). Patients with tuberculous pericarditis should be hospitalized and observed for evidence of cardiac tamponade. Triple-drug therapy should be started in the hospital and continued for at least 9 months. Patients with chronic pericardial effusions may benefit from oral prednisone therapy. The mortality rate is approximately 15% in HIV-negative patients and 20 to 35% in HIV-positive patients.¹²