Pericardial diseases

Congenital defects of the pericardium

Congenital defects of the pericardium are found in 1 in 10,000 autopsies. Pericardial absence can be partial left (70%), partial right (17%), or total bilateral (rare). Additional congenital abnormalities occur in approximately 30% of patients. Most patients with total pericardial absence are asymptomatic. Homolateral cardiac displacement and augmented heart mobility impose an increased risk for traumatic aortic dissection. Partial left-side defects can be complicated by herniation and strangulation of the heart through the defect (causing chest pain, shortness of breath, syncope, or sudden death). Surgical pericardioplasty (Dacron, Gore-Tex, or bovine pericardium) is indicated for imminent strangulation.

Acute pericarditis

Acute pericarditis is dry, fibrinous, or effusive, independent of its etiology. The major symptoms are retrosternal or left precordial chest pain (which radiates to the trapezius ridge, can be pleuritic or simulate ischemia, and varies with posture) and shortness of breath. A prodrome of fever, malaise, and myalgia is common, but elderly patients may not be febrile. A pericardial friction rub can be transient and monophasic, biphasic, or triphasic. A pleural effusion may be present. The heart rate is usually rapid and regular. Echocardiography is essential to detect effusion and concomitant heart or paracardial disease ( Table 75.1 ).

Hospitalization and symptomatic treatment are warranted. Nonsteroidal antiinflammatory drugs (NSAIDs) are the mainstay. Indomethacin should be avoided in elderly patients owing to its effect on reducing flow in the coronaries. Ibuprofen (300–800 mg TID) is preferred for its rare side effects, favorable impact on coronary blood flow, and large dose range. Colchicine 0.5 mg at least twice daily for 3 months added to aspirin or another NSAID reduced the recurrence rate impressively in the COPE trial, even at the first episode of pericarditis or even as monotherapy in “idiopathic” effusions. Colchicine is well tolerated, with fewer side effects than NSAIDs. Systemic corticosteroids should be restricted to connective tissue diseases and autoreactive or uremic pericarditis. Intrapericardial steroid application, as long-acting crystalloid triamcinolone, is effective for autoreactive effusions and avoids systemic side effects.

Chronic pericarditis

Chronic (>3 months) pericarditis includes effusive (inflammatory or hydropericardium in heart failure), adhesive, and constrictive forms. Symptoms (chest pain, palpitations, and fatigue) are usually mild and related to the degree of cardiac compression and pericardial inflammation. The detection of curable causes (e.g., tuberculosis; toxoplasmosis; myxedema; or viral, autoimmune, and systemic diseases) allows successful specific therapy. Symptomatic treatment and pericardiocentesis should be applied, if indicated. For recurrences, the etiology should be investigated intensely, and if no specific therapy is effective, balloon pericardiotomy or pericardiectomy may be considered.

Recurrent pericarditis

The term recurrent pericarditis encompasses (1) the intermittent type (symptom-free intervals without therapy) and (2) the incessant type (discontinuation of antiinflammatory therapy precipitates a relapse). Massive pericardial effusion, overt tamponade, or constriction is rare. Symptomatic management relies on exercise restriction and regimens used for acute pericarditis. Colchicine may be effective when NSAIDs and corticosteroids fail to prevent relapses. ^, It should be considered the first-choice treatment for recurrent pericarditis according to the CORE trial. Corticosteroids should be used only in patients with a poor general condition or in frequent crises. A common mistake could be to use a dose too low to be effective or to taper the dose too rapidly. The recommended regimen is prednisone 1–1.5 mg/kg for at least 1 month. If patients do not respond adequately, azathioprine (75–100 mg/day) or cyclophosphamide can be added.

Corticosteroids should be tapered over a 3-month period. Toward the end of the taper, introduce antiinflammatory treatment with colchicine (0.5 mg BID or TID) or an NSAID. Renewed treatment should continue for 3–6 months. Recently, it has been demonstrated in “idiopathic” pericarditis that previous corticosteroid treatment was a risk factor for recurrence or chronicity. Therefore corticosteroids should be administered after the definite exclusion of viral or bacterial infection of the pericardium. Pericardiectomy is indicated only for frequent and highly symptomatic recurrences resistant to medical treatment.

Pericardial effusion and cardiac tamponade

Pericardial effusion may appear as transudate (hydropericardium), exudate, pyopericardium, or hemopericardium. Large effusions are common with neoplastic, tuberculous, cholesterol, and uremic pericarditis and with myxedema and parasitoses. Loculated effusions are more common when scarring has supervened (e.g., postsurgical, posttraumatic, or purulent pericarditis). Effusions that develop slowly can be remarkably asymptomatic, whereas rapidly accumulating smaller effusions can present as tamponade. Cardiac tamponade is the decompensated phase of cardiac compression caused by effusion accumulation, leading to increased intrapericardial pressure. Heart sounds are distant. Orthopnea, cough, and dysphagia, occasionally with episodes of unconsciousness, can be observed. Insidiously developing tamponade may present as signs of its complications (renal failure, abdominal plethora, shock liver, worsening of glaucoma, and mesenteric ischemia). Tamponade without two or more inflammatory signs (typical pain, pericardial friction rub, fever, or diffuse ST-segment elevation) is usually associated with a malignant effusion (likelihood ratio, 2.9).

Electrocardiography demonstrates low QRS and T-wave voltages, PR-segment depression ( Fig. 75.1 ), ST-segment/T-wave changes, bundle branch block, and electrical alternans (rarely seen in the absence of tamponade). Microvoltage and electrical alternans are reversible after the drainage of the effusion and resolution of the inflammatory process. In chest radiography, large effusions are depicted as globular cardiomegaly with sharp margins (“water bottle” silhouette) ( Fig. 75.2 ). The size of effusions noted during echocardiography can be graded as (1) small (echo-free space in diastole <10 mm), (2) moderate (10–20 mm; Fig. 75.3 ), (3) large (≥20 mm), or (4) very large (≥20 mm and compression of the heart). In large pericardial effusions, the heart may move freely within the pericardial cavity (“swinging heart”), inducing pseudoprolapse and pseudosystolic anterior motion of the mitral valve, paradoxical motion of the interventricular septum, and midsystolic aortic valve closure ( Table 75.2 ). Up to one-third of patients with an asymptomatic large pericardial chronic effusion develop unexpected cardiac tamponade. Triggers for tamponade include hypovolemia, paroxysmal tachyarrhythmia, and intercurrent acute pericarditis.