CHAPTER SUMMARY AND CENTRAL ILLUSTRATION
This chapter outlines the pathophysiology and management of acute pericarditis as well as prognosis and potential complications (see Fuster and Hurst’s Central Illustration). Of pericardial diseases, acute pericarditis represents the most commonly encountered entity after pericardial effusions. Diagnosis typically involves combined clinical and electrocardiographic assessment, although further evaluation with laboratory studies and imaging (particularly echocardiography) is often required. Frequently, initial assessment yields no particular etiology, suggesting an idiopathic cause (often presumed viral), and treatment rests on combined therapy with nonsteroidal anti-inflammatory agents and colchicine. Less commonly, however, acute pericarditis may develop secondary to either alternative infectious processes (eg, bacterial) or noninfectious factors, including autoimmune/autoinflammatory disorders, pericardial injury (eg, surgery), metabolic derangements, malignancy, or medications. In such instances, treatment may include nonsteroidal anti-inflammatory agents and colchicine as well as therapy directed toward the underlying cause(s). Following its initial identification and treatment, acute pericarditis may be accompanied by one or more complicating factors, including arrhythmias and pericardial effusions (with/without tamponade). Depending on the response to therapy and the successful treatment of contributing factors, acute pericarditis may recur despite initial clinical resolution and can assume an incessant/chronic form. In such cases, a related, but distinct entity may arise in the form of constrictive pericarditis.
eFig 53-01 Chapter 53: Acute Pericarditis
ANATOMY AND PHYSIOLOGY OF THE PERICARDIUM
As a doubled-layered sac surrounding the heart, the pericardium consists of two separate layers: the outer parietal pericardium and the inner visceral pericardium (Fig. 53–1). A dense collagenous network chiefly forms this outer parietal pericardium, while the inner visceral pericardium contributes to the epicardium, the outermost contiguous layer of the heart. Together, these layers define the pericardial cavity, which is itself lined by a single-layered columnar mesothelium, the serous pericardium. The serous pericardium arises from two contiguous components: the visceral and parietal. The visceral component extends along the epicardium, contributes to the outer aspect of the visceral pericardium, and reflects onto the inner surface of the parietal pericardium at the base of the heart and proximal great vessels. This reflection gives rise simultaneously to separate recesses within the pericardial cavity, including the oblique and transverse sinuses, and constitutes the inner lining of the parietal pericardium. While the transverse sinus separates the great arteries and veins, the more inferior oblique sinus separates the left atrium and pulmonary veins. Together, they contribute to pericardial reserve volume.
Anatomy of the pericardium. External to the myocardium, the pericardium consists of an outer parietal pericardium and an inner visceral pericardium that define the pericardial cavity. The serous pericardium includes a visceral layer, which lines the surface of the visceral pericardium, and a parietal layer, a continuous reflection of the visceral layer that lines the inner aspect of the parietal pericardium. From Melduni RM. Chapter 77: Pericardial Diseases. In: Murphy ...