The Common Vein
less than 2 mm
Although the pericardium is visible over the right atrium and right ventricle in most individuals, it often is not visible over the lateral and posterior walls of the left ventricle.
The parietal and visceral layers are separated by a small amount of serous fluid—normally, about 15–50 mL
The left atrium is only partially covered by the pericardium; it has been suggested that this anatomic feature may contribute to the left atrial enlargement seen in patients with constrictive pericarditis
Recesses and Sinuses
superior pericardial recess
Oblique pericardial sinus betweeen the superior pulmonary veins
The heart and the base of the great vessels of the heart are contained in a fibroserous sac called the pericardium. Although the pericardium is usually described as a single sac, it actually consists of two sacs intimately connected with one another, but totally different in structure.
The Outer Sac- Parietal Pericardium
The outer sac, the fibrous pericardium, consists of fibrous tissue. The fibrous pericardium is attached at its base to the central tendon and to the muscular fibers of the left side of the diaphragm. It is also attached to the posterior surface of the sternum by the superior and inferior sternopericardial ligaments.
The Inner Sac – Visceral Pericardium
The inner sac, serous pericardium, is a delicate membrane composed of a single layer of flattened cells resting on loose connective tissue. The pericardial space with pericardial fluid separates the two layers. The visceral portion, or epicardium, covers the left ventricle and is continuous with the parietal layer which lines the fibrous pericardium.
The function of the heart coverings are to provide protection against friction. The outer sac (fibrous pericardium) consists of fibrous tissue. The inner sac (serous pericardium) lies within the fibrous sac. It is composed of a single layer of flattened cells resting on loose connective tissue. The space between these two sacs is merely a potential one. The serous pericardium consists of a visceral and a parietal portion. The heart and the base of the great vessels of the heart are contained in a fibroserous sac called the pericardium. Although the pericardium is usually described as a single sac, it actually consists of two sacs intimately connected with one another, but totally different in structure. The outer sac, the fibrous pericardium, consists of fibrous tissue. The inner sac, serous pericardium, is a delicate membrane composed of a single layer of flattened cells resting on loose connective tissue. The pericardial space with pericardial fluid separates the two layers. The function of the heart coverings are to provide protection against friction. Functionally although the intact pericardium is not essential, several functions have been attributed to it (1)limitation of intrathoracic heart movement (2)balancing right and left ventricular outputs through diastolic and systolic interactions (3) minimize friction between cardiac chambers and surrounding structures and (4)limitation of acute dilatation of the heart.
The pericardial space with pericardial fluid separates the two layers.
Diseases of the pericardium are not uncommon and include acute pericarditis, chronic pericarditis, constrictive pericarditis and cardiac tamponade to name a few.
Diagnosis of pericardial diseases may be suspected in patients presenting with chest pain, fever and signs of heart failure. On examination pulsus paradoxus may be appreciated, jugular veins may be distended with abnormal venous wave forms, heart sounds may be distant, a pericardial knock, or pathognomonic triphasic scratching sound of pericardial rub may be heard. Chest radiography may show an enlarged cardiac silhouette in cardiac tamponade with calcification in chronic pericarditis. EKG may show characteristic changes in pericarditis which global ST elevation and absent Q waves. Trans thoracic echo is useful to identify cardiac tamponade . CT may be indicated in cases of constrictive pericarditis.MRI may be superior to CT in identifying pericardial effusion . Cardiac catheterization is helpful in understanding the hemodynamics.
Medical therapy and surgical options are available depending on the disease process in question.
|Lipoma of the Pericardium|
|34800c01 cardiac heart pericardium fx lucent subcarinal angle altered dx lipoma of pericardium fat CTscan plain film scout Davidoff MD|
The heart and the base of the great vessels of the heart are contained in a fibro-serous sac called the pericardium. Although the pericardium is usually described structurally as a single sac, it actually consists of two sacs intimately connected with one another, but totally different in structure1. The outer sac, the fibrous pericardium, consists of fibrous tissue. The inner sac, serous pericardium, is a delicate membrane composed of a single layer of flattened cells resting on loose connective tissue.
The pericardium lies in the middle mediastinum posterior to the sternum and 2nd to 6th costal cartilages and anterior to 5th to eight vertebrae. It is a fibro serous sac that invest the heart and great vessels and is composed of two layers(1) Outer tough fibrous pericardium which blends with the central tendon of the diaphragm and (2) serous pericardium which has a parietal (lines the inner surface of the fibrous pericardium) and visceral layer (lines the external surface of the heart and great vessels) .
The attachments of the fibrous pericardium to neighboring structures limit excessive intrathorcic cardiac motion. The fibrous pericardium is fastened1 (1) above with the tunica adventitia of the great vessels and the pretracheal layer of the deep cervical fascia (2) anteriorly to the posterior surface of the sternum by the sternopericardial ligaments (3) inferiorly it blends with the central tendon of the diaphragm and (4)posteriorly it is bound by loose connective tissue to structures in the posterior mediastinum.
The serous pericardium encloses a potential space between the visceral and parietal layers called the pericardial space. This space usually contains 15- 50 ml of pale serous fluid and serves to minimize friction between cardiac chambers and surrounding structures2.
The reflection of the visceral pericardium over the cardiac chambers and surrounding great vessels forms the pericardial sinuses(transverse and oblique) and recesses in the pericardial space4. The transverse pericardial sinus is a passage in the pericardial sac that lies just above the left atrium, and is bound anteriorly by the pericardial reflections over the aorta and pulmonary artery and posteriorly by pericardial reflection extending transversely between the right and left superior pulmonary veins. On the left and right it communicates with the main pericardial cavity. The oblique sinus lies in the pericardial cavity posterior to the left atrium and anterior to the esophagus. It is bound laterally by the pericardial reflections over the pulmonary veins and IVC. The transverse sinus lies superior and anterior to the oblique sinus and is separated from it at this level by two layers of serous pericardium transversely connecting the right and left superior pulmonary veins .
The recesses are pericardial cavity diverticula between major vessels. There are categorized 4 on the basis of whether they arise from the (1) pericardial cavity proper,(2) the transverse sinus , or the(3) oblique sinus.
The pulmonary vein recesses 4, which are usually small, lie along the lateral borders of the heart between the superior and inferior pulmonary veins. The anatomy of these recesses are important in catheter ablation of atrial fibrillation.
The superior aortic recess 4 extends anterior to the ascending aorta and has anterior, posterior, and right lateral portions . The anterior portion of the superior aortic recess has a characteristic triangular shape as it insinuates itself between the ascending aorta and the main pulmonary artery. The lateral portion similarly insinuates itself between the ascending aorta and the SVC. The posterior portion lies posterior to the ascending aorta. The inferior portion of the superior aortic recess communicates with the transverse sinus.
The inferior aortic recess4 extends inferiorly from the transverse sinus posterior to the aorta and anterior to the left atrium, extending inferiorly to the level of the aortic valve.
The right and left pulmonic recess 4 lie inferior to the right and left pulmonary arteries, respectively.
The upper right lateral extension of the oblique sinus lies behind the right pulmonary artery and medial to the bronchus intermedius, where it is called the posterior pericardial recess 4.
Clinical considerations :
Knowledge of the anatomy of pericardial sinuses and recesses helps to avoid a misdiagnosis of lymphadenopathy or other mediastinal pathology (thymic , aortic dissections , esophageal )
- Renal Failure
- Aortic Dissection
- Acute and recurrent pericarditis
- Pericardial effusion without major hemodynamic compromise
- Cardiac tamponade
- Constrictive pericarditis
- Effusive-constrictive pericarditis
Broderick LS, Brooks GN, and Kuhlman JE. Anatomic Pitfalls of the Heart and Pericardium. RadioGraphics 2005;25:441-453
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