The pericardium is a tough, fibrous, outer coating with discrete attachments to the sternum, great vessels, and diaphragm and an inner membranous coat.

It is divided into two layers, the first of which is called the parietal one, and the second the visceral component. The pericardium contains approximately ten to fifteen cc's of serous fluid. The function of the pericardium is to limit or prevent acute pathological distension of the heart once the pericardial reserve volume has been used up and the pericardium is stretched. It does not cover the left atrium, which lies anterior to the pericardium.
The pericardial attachments maintain the heart in its normal position and are so arranged that external forces exerted on the pericardium by respiration or changes in body posture tend to cancel each other and maintain a constant heart position.

 

PERICARDIAL CYSTS

Pericardial, or mesothelial, cysts are the most frequent benign "tumors" of the pericardium. They are usually found coincidentally on a routine roentgenogram. However, 25 to 30 percent of the patients will have chest pain, dyspnea, cough, or paroxysmal tachycardia. Pericardial cysts occur most frequently in the third or fourth decade of life and equally among men and women. The right costophrenic location is the most common, although they may present in the upper mediastinum. Only rarely does the cyst connect with the pericardial cavity. Clinically and radiographically, they resemble other tumors of the pericardium. Hemodynamically significant cardiac-chamber compression rarely results. Echocardiography. CT scanning, and MRI are most helpful in the differential diagnosis. Surgical excision completely relieves symptoms and confirms the diagnosis;however, percutaneous aspiration of the cystic contents is an attractive alternative to surgical resection.A case of video-asssisted surgical excision of a recurrent pericardial cyst has been reported.