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The pericardium is a 2-layered sac that contains the heart and
the proximal parts of the great vessels. The outer surface of the
sac is termed the parietal pericardium and is lined
by mesothelial cells. The inferior part of the sac is attached to
the diaphragm. The inner layer of the sac, also lined by mesothelial
cells, is attached to the cardiac surface and is known as the visceral
pericardium. A small amount of fluid fills the cavity between
the pericardial layers and acts as a lubricant so that the heart
can move within the sac. The parietal pericardium has blood and
lymphatic vessels. Disorders that affect the pericardium may be primary
or secondary to disease elsewhere in the body, including the heart
itself.
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Whatever the cause, there are only 3 manifestations: acute or
chronic inflammation of the pericardial sac in response to injury
or accumulation of fluid between the 2 layers—a pericardial
effusion with or without a tamponade.
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Acute pericarditis has many causes (see Table
491-1). No matter what the cause, the presentation is similar.
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1. Chest pain is usually precordial and often referred
to the neck, shoulder, or epigastrium. The pain is sharp or burning
and is usually made better by sitting up and leaning forward. It
is made worse by taking in a deep breath because inspiration lowers
the diaphragm, pulls the pericardial sac down, and narrows it, thereby
causing the 2 ...