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The Echo Manual

CHAPTER 12

Pericardial Diseases Ling-His Lieng, Raúl E. Espinosa and Jae K. Oh

Acquired abnormalities of the pericardium include inflammation, effusion, neoplasia, fibrosis, and calci- fication, which can manifest clinically as chest pain, dyspnea, heart failure, hypotension, and even cardio- genic shock. Other structural abnormalities include con- genital absence of the pericardium and pericardial cyst. Echocardiography is the most important clinical tool in the recognition and management of these pericardial diseases. Detection of pericardial effusion was the first clinical application of echocardiography, using an “A” (amplitude) mode in 1963 (4) (see Fig. XX). This tech- nique subsequently revolutionized the diagnosis of peri- cardial effusion and tamponade and is now routinely used to safely guide pericardiocentesis (5). Comprehensive 2D and Doppler echocardiography is also fundamental in the diagnosis of constrictive pericarditis (6,7). When trans- thoracic imaging windows are unfavorable, transesoph- ageal echocardiography (TEE) can help in measuring pericardial thickness (8), detecting loculated pericardial effusion or other structural abnormalities of the peri- cardium, and evaluating diastolic function for tampon- ade or constrictive physiology. Three-dimensional (3D) echocardiography may in some cases yield incremental information to 2D imaging. The various applications of echocardiography in the evaluation of pericardial dis- eases are illustrated in this chapter. CONGENITALLY ABSENT PERICARDIUM Congenital absence of the pericardium is a rare disorder, which usually involves complete absence of the left side of the pericardium. Absence of the right hemopericardium :ROWHUV .OXZHU ,QF 8QDXWKRUL]HG UHSURGXFWLRQ R I WKH FRQWHQW LV SURKLELWHG Q1 Q2

The normal pericardium, which has an anatomic thick- ness of ≤ 1 to 2 mm (1), consists of an outer layer called the fibrous pericardium and an inner layer called the serous pericardium. The visceral layer of the serous peri- cardium, or epicardium, covers the heart and proximal great vessels. There is varying amount of fat between the myocardium and the epicardium. It is reflected to form the parietal pericardium, which lines the fibrous peri- cardium (Fig. 12-1). The reflections of the serous pericar- dium between the arteries and the veins form sinuses and recesses (Fig. 12-2). The pericardium provides mechanical protection for the heart and exerts notable hemodynamic effects on the atria and ventricles. The finite compliance of the normal pericardium limits cardiac chamber disten- tion. Ventricular volume is greater at any given ventricular filling pressure with the pericardium removed than with the pericardium intact. Through the same mechanism, the pericardium also promotes diastolic coupling, or inter- dependence, between the two ventricles. The increased filling of one ventricle reduces the filling of the other. This phenomenon underlies the pathophysiology of car- diac tamponade and constrictive pericarditis. Apart from these mechanical functions, the pericardial mesothe- lium produces 25 to 50 mL of fluid, which has lubricant, anti-infective, fibrinolytic, and paracrine properties. Fat deposited around the pericardium, specifically epicardial fat, reflects visceral adiposity and may be a marker of car- diometabolic risk factors (2). Pericardial fluid is drained by the lymphatic system, and venous drainage is provided by pericardiophrenic veins that drain into the innomi- nate veins (3). The pericardium has extensive autonomic innervation.

Fig. 12-1

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