The Visceral Pericardium is Continuous With

Pericardium

The pericardium is a double-layer—fibrous outermost layer and serous innermost layer—sac of fibroelastic/fibroserous tissue encasing the heart, anchoring it to the mediastinum (a passageway for many structures that pass through the thorax), and forming a cavity filled with a serous fluid.

From: Comparative Veterinary Anatomy , 2022

The heart

Chaya Gopalan Ph.D., FAPS , Erik Kirk Ph.D. , in Biology of Cardiovascular and Metabolic Diseases, 2022

1.3 The pericardium

The pericardium , which translates as "around the heart," is a double-layered connective tissue membrane that surrounds the heart like a sac and, therefore, is also called as a pericardial sac (Fig. 1.2). The outer sturdy parietal pericardium consists of dense connective tissue that protects the heart and maintains its position within the thoracic cavity. The inner visceral pericardium, or epicardium, is attached to the heart and is part of the heart wall. There is a space between the visceral pericardium and the parietal pericardium and is referred to as the pericardial cavity. The pericardium secretes a small amount of serous fluid that fills the pericardial cavity and coats the two pericardial layers which serves as a lubricant to reduce friction as the heart expands and contracts.

Fig. 1.2. Pericardial membranes and layers of the heart wall [2].

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780128234211000111

Cardiac surgery for constrictive pericarditis

Jessica Nathalia González , ... Michael Magarakis , in Debulking in Cardiovascular Interventions and Revascularization Strategies, 2022

Abstract

The pericardium is a protective cardiac biologic tissue. The pericardial structure consists of an avascular, double-walled sac containing two layers: the visceral pericardium, which is a thin layer comprising an inner serous monolayer and pericardial physiologic fluid, and the parietal pericardium, which consists of an outer fibroelastic layer. There are two pericardial sinuses: transverse and oblique. The pericardium serves important ligamentous, membranous, metabolic, reflexive, and mechanical functions that are described within the text of this chapter. Constrictive pericarditis is a serious cardiac pathologic process with profound clinical and hemodynamic implications. In constrictive pericarditis, chronic fibrous tight thickening of the pericardial tissue develops secondary to inflammation. As a result, the pericardial elasticity and compliance are adversely effected, in a process that severely impairs cardiac physiology. Clinically, constrictive pericarditis commonly presents with a picture of right-sided heart failure including symptoms of fatigue, exertional dyspnea, and peripheral edema. Associated left cardiac chambers dysfunction also presents as pulmonary congestive symptoms, chest pain, palpitations, abdominal symptoms, and frank anasarca. The unique physical examination findings when this pathology is encountered are delineated in this chapter. The diagnosis of constrictive pericarditis involves physical examination, electrocardiography, chest radiography, and echocardiography. Further evaluation and confirmation include cardiac imaging with computed tomography, magnetic resonance, and, when indicated, right and left heart catheterization.

Definitive surgical management is commonly performed through pericardiectomy. This operation remains technically challenging and its various approaches, challenges, and complications are described. Long-term survival after pericardiectomy is largely dependent on etiology and on patient comorbidities such as older age, New York Heart Association (NYHA) class, renal dysfunction, pulmonary hypertension, increased Child-Pugh liver disease, previous chest irradiation, and hyponatremia. Postoperatively, most patients exhibit improved hemodynamic condition, improved cardiac function, and become symptom free providing that accurate pre-op assessment, adequate patient selection, and timely surgical intervention are performed.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780128214510000197

Pericarditis

Marie-Eve Fecteau , in Comparative Veterinary Anatomy, 2022

Function

The pericardium is a double-layer—fibrous outermost layer and serous innermost layer—sac of fibroelastic/fibroserous tissue encasing the heart, anchoring it to the mediastinum (a passageway for many structures that pass through the thorax), and forming a cavity filled with a serous fluid. It protects the heart from external shock (shock absorption) and provides lubrication of the heart during each cardiac contraction. The position of the heart in the mediastinum thus limits its motion. The pericardium also isolates or shields the heart from infections associated with other mediastinal and thoracic cavity organs—i.e., the lungs—and limits the heart from excessive distention associated with an acute volume overload.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780323910156000911

Predatory marine bivalves: A review

Brian Morton , Fabrizio Marcondes Machado , in Advances in Marine Biology, 2019

11.2 The heart, pericardial gland and kidneys

The pericardium of all the septibranchs examined hitherto is situated centro-dorsally in the visceral mass and is of the typical bivalve form and relative size. It contains a central antero-posterior aligned ventricle, traversed by the rectum, and lateral auricles ( Fig. 14A ). The paired kidneys are typically situated postero-laterally to the pericardium as in all the bivalves hitherto studied and the structure of these in the verticordiid Trigonulina ornata has been demonstrated anatomically by Morton et al. (2019: fig. 18). The loosely arranged kidneys comprise chords of excretory cells, also illustrated in Fig. 14A at a greater magnification, which extract waste products from the blood and eventually come to contain a growing group of excretory droplets that ultimately coalesce to form a darkly staining excretory droplet. When these dehisce from the kidney they leave behind vacuolated cells. Discharged excretory droplets pass into the pericardium and thence into the reno-pericardial apertures to be excreted from the left and right renal apertures into the supra-branchial/supra-septal chambers and thence removed via the exhalant siphon.

Fig. 14. Sections through the heart and kidney of (A) Trigonulina ornata and (B) Spheniopsis brasiliensis.

Panel (A) Redrawn after Morton, B., Machado, F.M., Passos, F.D., 2019. The anatomy of the miniature ostracod predator Trigonulina ornata (Bivalvia: Anomalodesmata: Verticordiidae) from continental shelf waters off Brazil. Mar. Biodivers. 49 (6), https://doi.org/10.1007/s12526-019-01017-y, fig. 16, Panel (B) Redrawn after Morton, B., Machado, F.M., Passos, F.D., 2016b. The organs of prey capture and digestion in the miniature predatory bivalve Spheniopsis brasiliensis (Anomalodesmata: Cuspidarioidea: Spheniopsidae) expose a novel life history trait. J. Nat. Hist. 50, 1725–1748: fig. 10.

The epithelia of the auricles comprise the pericardial gland (Fig. 14B) that was first identified for Cuspidaria cuspidata by Grobben (1892). According to the pioneering researches of White (1942), the pericardial glands serve an ultra-filtration function for the blood and it is probable that they serve a similar role in the septibranchs. It was experimentally demonstrated for the freshwater bivalve Dreissena polymorpha (Pallas, 1771) that ingested particles of colloidal graphite were passed through the intestine and taken by amoebocytes into the blood. They were then abstracted from the blood in the heart by the pericardial glands and then excreted via the kidneys (Morton, 1969: fig. 3). The pericardial glands of Spheniopsis brasiliensis have been described and illustrated by Morton et al. (2016b: fig. 10) and have the same basic structure described for other, non-predatory, bivalves.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/S006528811930032X

Feline Cardiomyopathy

Mark Oyama , Simon Bailey , in Comparative Veterinary Anatomy, 2022

Pericardium

The pericardium (Fig. 4.4-8) is a fibroserous sac that surrounds the heart. Embryologically, it begins as a deep invagination of the ventral mediastinum around the developing heart. These origins are reflected postnatally by the phrenico-pericardiac ligament—a short, strong band of connective tissue covered by pleura which firmly attaches the pericardium to the caudoventral thoracic wall (in dogs and cats, to the ventral portion of the diaphragm).

Figure 4.4-8. Diagram of the pericardium.

These origins are further reflected in the structure of the pericardial cavity, which is like that of the pleural cavity: parietal and visceral layers of mesothelium are separated by a thin film of serous fluid, which lubricates the 2 surfaces and allows them to glide over each other during the cardiac cycle.

The parietal layer of the pericardium has a strong, fibroelastic outer coating—which itself is covered by the visceral pleura—giving the parietal pericardium a whitish, semi-opaque appearance. This outer part of the pericardial sac is generally referred to as the fibrous pericardium or simply as the pericardium. Its fibrous tissue is continuous with that of the phrenico-pericardiac ligament. The visceral layer of the pericardium is thin and firmly adhered to the underlying myocardium, so it is generally referred to as the epicardium.

The 2 layers of pericardium (parietal and visceral) fuse where the ascending aorta and the pulmonary trunk exit the heart base. Thus, the pericardial sac completely encloses the heart—i.e., the pericardial space does not communicate with the mediastinal space or the pleural cavity—and only at its base is the heart attached to the fibrous pericardium.

Excess fluid in the pericardial sac—whether serous fluid (pericardial effusion), blood (hemopericardium), or inflammatory exudate (exudative pericarditis)—may result in compression of the heart, a condition known as "cardiac tamponade" (Fr. tampon a plug). Excessive pericardial fluid prevents normal dilation and filling of cardiac chambers, impeding return of blood to the heart and resulting in distention of peripheral veins such as the external jugular vein. When severe, the combination of pericardial fluid accumulation and reduced cardiac filling may muffle the heart sounds on thoracic auscultation. (Note: Heart sounds may also be muffled with pleural effusion and in obese patients, it is not specific for pericardial pathology.)

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780323910156000261

Gene- and Cell-Based Therapy for Cardiovascular Disease

José Marín-García M.D. , in Post-Genomic Cardiology (Second Edition), 2014

Pericardial injection

The use of the pericardial sac for gene transfer delivery is based on the anatomical proximity between the pericardium and the myocardium and the ability to access this compartment percutaneously. Furthermore, because the pericardial sac represents a closed cavity higher vector concentrations, prolonged vector persistence, and lower leakage to off-target tissues can be achieved. ^11,98,99 Based on these considerations, the pericardial space has been used not only for gene transfer delivery, but also for pharmaceutical drug delivery and electrophysiological procedures. ^123–126 Percutaneous pericardial injection through a substernal/xiphoidal approach with the guidance of imaging techniques is a minimally invasive and relatively safe procedure, and therefore a preferable method. ¹²⁷ Catheter-based pericardial injection has also been applied to cardiac gene delivery in a canine model. ¹²⁸

However, despite the potential anatomical advantages of the pericardium, pericardial gene delivery has resulted in transgene expression mainly in pericardial cells with minimal expression in the myocardium. ^123,127,129 Coinjection of proteolytic enzymes and polyethyleneimine with the vectors have enhanced the rate of myocardium transduction by 40%, increasing, however, cardiac toxicity. ^123,130 A modification of the percutaneous pericardial injection, based on slow release of vector along with a permeabilizing, nontoxic agent, has recently been reported to improve the efficiency of this method. ¹²⁷

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780124045996000238

Cardiology

Brenna Colleen Fitzgerald •  , Hugues Beaufrère , in Current Therapy in Avian Medicine and Surgery, 2016

Pericardium

The heart is enclosed within a fibrous, relatively noncompliant pericardial sac (Figure 6-10 ), which normally contains a very small volume of serous fluid that serves to lubricate the movement of the heart within the pericardial sac. The outer fibrous layer of the pericardium is continuous with the adventitia of the great vessels, and attachments exist between the pericardium and the sternal plate, the hilus of the lungs, the adjacent air sacs, and the liver. ^{1 , 2 , 10 , 14 , 16} The last of these attachments is via the hepatopericardial ligament, which is continuous with the ventral mesentery caudally. ^{13 , 14} The heart is thereby well anchored within the cranioventral coelom (pericardial coelom) and its apex between the liver lobes and hepatic coelomic cavities. ^{1 , 2 , 10}

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B978145574671200015X

Myocarditis and Pericarditis

Angita Jain , ... DeLisa Fairweather , in Reference Module in Biomedical Sciences, 2021

4.2 Pericardial effusion

Pericardial effusion is defined as the collection of fluid in the pericardial sac (typically around 10–50   mL of pericardial fluid within the pericardial sac) that can lead to cardiac tamponade. Pericardial effusion is a common complication of acute pericarditis; however, malignancy or autoimmune diseases can cause pericardial effusion with or without acute pericarditis. The clinical presentation of pericardial effusion ranges from dyspnea, orthopnea, chest pain and/or fullness to overt cardiac tamponade. The diagnosis of pericardial effusion is by echocardiography, CT scan or cardiac MRI. If inflammatory signs are present, then the management is that of pericarditis according to the ESC guidelines for the management of pericardial diseases (Adler et al., 2015a). In cases where there are no inflammatory signs present, there is a higher risk of neoplastic etiology. In cases of symptomatic pericardial effusion, drainage of the fluid is recommended. Colchicine is the drug of choice for pericardial effusion with an inflammatory etiology.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780128204726000918

Cardiovascular disorders

Roger W. Blowey BSc BVSC FRCVS FRAgS , A. David Weaver BSc DR MED VET PHD FRCVS , in Color Atlas of Diseases and Disorders of Cattle (Third Edition), 2011

Septic pericarditis and myocarditis

Pathogenesis

commonly follows traumatic reticuloperitonitis, less commonly from hematogenous spread.

Clinical features

septic pericarditis is usually a sequel to penetration of the pericardial sac by a wire that has migrated from the reticulum through the diaphragm (see "Traumatic reticulitis", p. 69). Congestive cardiac failure is the result of reduced contractility. In the Charolais bull in 6.5 a massive volume of yellow pus ("scrambled egg" appearance) fills the pericardial sac. The surface (A) below the pus is the thickened, partly fibrosed epicardium. The thickness of the pericardial wall can be judged from the depth of the sternum (B). Another illustration of septic pericarditis is seen in 6.6 , with organized purulent exudate adhering to the epicardial surface as well as pericardium.

Heart failure may result from migration of the foreign body (wire, A) into the myocardium itself (6.7). Ventral edema is often a sequel to septic pericarditis caused by traumatic reticulitis.

The absence of a septic track from the reticulum through the diaphragm to the pericardium and heart in another case (6.8) indicates that fatal myocardial abscessation can sometimes arise through hematogenous infection. In this cow (6.8), in which the original septic focus was a septic pedal arthritis, the abscess (opened) involves the papillary muscles and myocardium.

Cardiac tamponade due to massive sudden accumulation of blood in the pericardial sac (4.68) following tire wire penetration from the reticulum results either in sudden death (as here) or congestive cardiac failure.

Management

treatment of individual cases is rarely successful.

Control

see "Traumatic reticulitis" (p. 69)

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780723436027000121

Canine and Feline Diaphragm

Elissa K. Randall , in Textbook of Veterinary Diagnostic Radiology (Seventh Edition), 2018

Peritoneopericardial Diaphragmatic Hernias

A peritoneopericardial diaphragmatic hernia occurs when abdominal viscera herniates into the pericardial sac through a congenital hiatus formed between the tendinous portion of the diaphragm and the pericardial sac. This has been reported to occur in littermates, ²³ and a predisposing trait may be carried on a simple autosomal recessive gene in cats, with a 1 : 500 to 1 : 1500 rate of incidence. ²⁴ Domestic long-hair cats and Himalayans appear to be overrepresented. ²⁵ The hernia may have been present from birth or acquired. Mild increases in intraabdominal pressure may cause abdominal organs to herniate through a congenital hiatus.

Peritoneopericardial hernias may produce clinical signs, but are often an incidental radiographic finding. These hernias may be present in old or young animals. ^5,25-30 The liver is herniated most frequently; the stomach, omentum, and small bowel have a less frequent occurrence of herniation. ³¹ Hepatic cysts have also been reported to be associated with liver herniation into the pericardial sac. ³²

Radiographic signs associated with peritoneopericardial hernias are listed in Box 32.2. Herniated abdominal organs in the pericardial sac are usually caudal, or caudal and lateral, to the heart. Gas- or ingesta-filled hollow visceral organs are not difficult to identify within the pericardial sac, but the conspicuity of the gas-containing viscus may be a function of body position during radiography (Fig. 32.16 ). Radiographically, gas within the bowel is in abrupt contrast to the adjacent structures of soft tissue opacity. Solid parenchymal organs, unless surrounded by omentum, are difficult to distinguish as separate structures within the pericardium. When abdominal organs are herniated into the pericardial sac, cranial and ventral organ displacement within the abdomen may be seen; but this displacement is usually not as pronounced as that noted with traumatic diaphragmatic hernias.

A large, round cardiac silhouette and a cardiac silhouette with an abnormal convex projection on the caudal border are signs consistent with peritoneopericardial diaphragmatic hernias. These two signs depend on the amount of abdominal viscera within the pericardial sac. Large amounts of viscera produce a large, round cardiac silhouette, whereas smaller amounts, such as a portion of the liver or stomach, may produce only an abnormal convex caudal cardiac border. A large, round silhouette must be differentiated from pericardial effusion, generalized heart enlargement, or both. An abnormally convex caudal cardiac border must be differentiated from neoplasia, pleural granulomas, or localized pleural fluid.

An indistinguishable outline to the ventral diaphragmatic surface and the caudal ventral cardiac silhouette is produced by the communication between the two structures. This finding must be differentiated from normal contact between the heart and diaphragm, pleural fluid, localized pleuritis, and pleural granulomas.

An apparently confluent silhouette between the heart and diaphragm may appear as a wide caudal mediastinum; depending on the size of the communication, it may or may not be seen radiographically. This confluent silhouette must also be differentiated from other pathologic conditions. On the lateral view, identification of the dorsal peritoneopericardial mesothelial remnant between the heart and diaphragm is a consistent radiographic sign of peritoneopericardial hernia in cats (Fig. 32.17). ³³ Additional radiographic studies that may be performed to confirm a diagnosis include oral administration of barium sulfate, nonselective angiography, ³⁴ and peritoneography. Barium sulfate may be used to demonstrate gastrointestinal structures within the pericardial sac or cranial ventral displacement of abdominal structures (Fig. 32.18).

Ultrasonography has been successfully used to diagnose peritoneopericardial diaphragmatic hernias. ^15-18 Ultrasonography is a reliable imaging modality to use for documentation of a peritoneopericardial hernia in patients where soft tissue opaque abdominal structures are in the pericardial sac and difficult to differentiate from the heart on radiographs. If available, an ultrasound examination should be considered before contrast examinations are performed to assist in the diagnosis of peritoneopericardial diaphragmatic hernia.

CT can assist in determining which structures are herniated, and it can confirm a peritoneopericardial diaphragmatic hernia in cases in which radiographs are not conclusive or when more information is desired prior to surgery.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780323482479000449

mccandlesstiolsell.blogspot.com

Source: https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/pericardium