Disorders of the pericardium constitute a diverse group of pathologies, ranging from benign congenital structural abnormalities, such as pericardial cyst, to life-threatening entities, such as cardiac tamponade and constrictive pericarditis. Although pericardial diseases are not uncommon in daily practice, physicians including cardiologists tend to be less familiar with managing these diseases. This can lead to a delay in the diagnosis (patients with constriction might have been treated for “refractory” heart failure for years) or incomplete or inadequate treatment. We provide herein a concise and practical approach to pericardial diseases for cardiovascular practitioners. We have also incorporated the recommendations from the 2015 European Society of Cardiology (ESC) Guidelines on the Diagnosis and Management of Pericardial Diseases1 (a summary of the most relevant recommendations is also provided in the chapter).
The human pericardium has two distinct layers; the serosa is composed of a single column of mesothelial cells that surrounds all four cardiac chambers and the proximal great vessels and reflects on itself to form the inner surface of the fibrosa, a fibrocollagenous structure (Figs. 66–1 and 66–2). This monolayer of serosal cells covering the surface of the heart and epicardial fat is also called the visceral pericardium, whereas the fibrosa and the reflection of the serosa make the parietal pericardium. Pericardial fluid, an ultrafiltrate of the plasma, accumulates between the serosal layers; normal pericardial fluid volume ranges from 15 to 50 mL. As opposed to the visceral pericardium, the fibrosa does not cover the cardiac surface in its entirety; pericardial reflections at the level of great vessels give origin to the pericardial sinuses. The two most important are the transverse sinus, which lies between the great arteries (aorta and pulmonary artery) and the great veins (pulmonary veins and vena cavae), and the oblique sinus, which has the shape of an inverted U and lies behind the left atrium as the fibrosa reflects around the pulmonary veins. Pericardial fluid can accumulate in these sinuses, increasing pericardial volume if necessary, and therefore, constituting the pericardial reserve (Fig. 66–3).
Anatomy of the pericardium. Gross anatomy specimens showing the intact pericardium (A) and post excision of the anterior pericardial surface (B) and exposure of the pericardial cavity. Used with permission from Dr. William D. Edwards, Mayo Clinic, Rochester, MN USA.
Pericardial layers. Illustration showing a detailed view of the pericardium and its layers in relationship to the myocardium. Reproduced with permission from from Blausen.com staff, “Blausen gallery 2014,” Wikiversity Journal of Medicine. DOI: 10.15347/wjm/2014.010.
Pericardial reserve and pericardial pressure-volume curves in cardiac tamponade. A. The pressure-volume curve observed in acute cardiac tamponade; note the much ...