Clinical Significance Of Transverse Pericardial

Chapter 2: FUNCTIONAL ANATOMY OF THE HEART CORRELATIVE ANATOMY

This section in this chapter is an illustrated review of applied cardiac anatomy. The clinical significance of the anatomy described is highlighted in italics.

Pericardium

The fibrous (parietal) pericardium is a resilient sac that envelops the heart and attaches onto the great vessels.!5 Almost the entire ascending aorta and main pulmonary artery and portions of both venae cavae and all four pulmonary veins are intrapericardial (Fig. 2-19). These are important anatomic landmarks to remember when evaluating diseases ofthe pericardium. Given the intrapericardial location ofthe ascending aorta, diseases such as localized aortic wall hematoma, aortic dissection, or aortic rupture can produce a rapidly fatal hemopericardium. Because the sac is collagenous, with little elastic tissue, it cannot stretch acutely. In patients with total anomalous pulmonary venous connection, the confluence of pulmonary veins is intrapericardial. In contrast, the right and left pulmonary arteries and ductal artery(ductus arteriosus) are extrapericardial structures.16

Parietal Pericardial Membrane

Figure 2-19: Anterior view of the heart. The anterior portion of the parietal pericardium has been http://cardiology.accessmedicine.com/server-java/Arknoid/amed/hurst/co_chapters/ch002/ch002_p03.html (1 / 39) [2003-1-4 11:45:05]

Figure 2-19: Anterior view of the heart. The anterior portion of the parietal pericardium has been http://cardiology.accessmedicine.com/server-java/Arknoid/amed/hurst/co_chapters/ch002/ch002_p03.html (1 / 39) [2003-1-4 11:45:05]

removed, exposing the intrapericardial portions of the superior vena cava (SVC), ascending aorta (Ao), and pulmonary trunk (PT). LV, left ventricle; RA, right atrium; RV, right ventricle.

The serous pericardium forms the delicate inner lining of the fibrous pericardium as well as the outer lining of the heart and great vessels (visceral pericardium). Over the heart, it is referred to as the epicardium, and it contains the epicardial coronary arteries and veins, autonomic nerves, lymphatics, and a variable amount of adipose tissue. The junctions between the visceral and parietal pericardium lie along the great vessels and form the pericardial reflections. The reflections along the pulmonary veins and vena cavae are continuous and form a posterior midline cul-de-sac known as the oblique sinus. Behind the great arteries, the transverse sinus forms a tunnel-like passageway (Fig. 2-20). After open-heart surgery, localized accumulation of blood within the oblique sinus can produce isolated left atrial tamponade.16 Similarly, a hematoma adjacent to the low-pressure right atrium can cause isolated right atrial tamponade. With increasing age and with obesity, fat can accumulate within the parietal pericardium and epicardium.i6 When imaging the heart, it is important not to misinterpret fat as an abnormal structure or a tumor.

Oblique Pericardial Sinus

Figure 2-20: Tomographic section in the short-axis plane of the body, looking from apex toward the base, showing the oblique (OS) and transverse (TS) pericardial sinuses. Ao, ascending aorta; DAo, descending thoracic aorta; LA, left atrium; LAS, left aortic sinus; LMA, left main coronary artery: PS, pericardial sac; PV, pulmonary valve; RAA, right atrial appendage; SVC, superior

Figure 2-20: Tomographic section in the short-axis plane of the body, looking from apex toward the base, showing the oblique (OS) and transverse (TS) pericardial sinuses. Ao, ascending aorta; DAo, descending thoracic aorta; LA, left atrium; LAS, left aortic sinus; LMA, left main coronary artery: PS, pericardial sac; PV, pulmonary valve; RAA, right atrial appendage; SVC, superior vena cava.

Cardiac Skeleton

The four cardiac valves are anchored to their annuli, or valve rings. These fibrous rings, at the base of the heart, join to form the fibrous skeleton of the heart!6 (Q+;0; Fig. 2-21). The centrally located aortic valve forms the cornerstone of the cardiac skeleton, and its fibrous extensions abut each of the other three valves. The cardiac skeleton contains not only the four valve annuli but also the membranous septum and the aortic intervalvular, right, and left fibrous trines. The fibrous trigones form the anatomic substrate for direct mitral-aortic continuity!^ Figs. 2-21, Plate

8, and 2-22). The intervalvular fibrosa also forms part of the floor of the transverse sinus (see Figs. 2-22 and 2-33). In patients with infective endocarditis ofthe mitral or aortic valves, the infection may burrow through the intervalvular fibrosa and produce fistulas betwn the left ventricle and the adjacent left atrium, ascending aorta, or transverse sinus.17

Intervalvular Fibrosa Abscess

Figure 2-22: Long-axis section of the left ventricle. The intervalvular fibrosa (dashed triangle) lies between the anterior mitral leaflet and the posterior cusp of the aortic valve and abuts the floor of the transverse pericardial sinus (*). Ao, ascending aorta; IW, inferior wall; LA, left atrium; LV, left ventricle; RVO, right ventricular outflow; VS, ventricular septum.

Figure 2-22: Long-axis section of the left ventricle. The intervalvular fibrosa (dashed triangle) lies between the anterior mitral leaflet and the posterior cusp of the aortic valve and abuts the floor of the transverse pericardial sinus (*). Ao, ascending aorta; IW, inferior wall; LA, left atrium; LV, left ventricle; RVO, right ventricular outflow; VS, ventricular septum.

Long Axis Aortic Valve

Figure 2-33: Long-axis view of the right ventricular outflow (RVO) tract showing the pulmonary valve (PV) and main pulmonary artery (MPA). AoV, aortic valve; LA, left atrium; LCA, left coronary artery; LVO, left ventricular outflow; MV, mitral valve; PulV, pulmonary vein; VS, ventricular septum; *, transverse sinus.

The right fibrous trigone, also known as the central fibrous body, welds together the aortic, mitral, and tricuspid valves and forms the largest and strongest component of the cardiac skeleton. It is through the right fibrous trigone that the atrioventricular (His) bundle passes. Otherwise, the fibrous cardiac skeleton serves to electrically isolate the atria from the ventricles. Diseases or surgical alterations of one valve may affect the shape or angulation of adjacent valves (e.g., aortic valve replacement causing severe mitral regurgitation) and may affect the nearby coronary arteries or conduction tissue.17

Tricuspid Valve

The tricuspid valve is comprised of five components (i.e., annulus, leaflets, commissures, chordae tendineae, and papillary muscles). The anterior tricuspid leaflet is the largest and most mobile and forms an intracavitary curtain that partially separates the inflow and outflow tracts of the right ventricle (Fig. 2-23). The posterior leaflet is usually the smallest. The septal leaflet is the least mobile because of its many direct chordal attachments to the ventricular septum. A distensible fibroadipose annulus is unique to the tricuspid valve.17 Consequently, dilatation of the right ventricle commonly produces circumferential tricuspid annular dilatation that results in variable degrees of tricuspid valve regurgitation.16

Short Axis View Coronary Artery

Figure 2-23: This oblique short-axis view of the heart shows the triangular-shaped tricuspid orifice (TV) and the elliptical mitral orifice (MV) at midleaflet level. The anterior tricuspid and anterior mitral leaflets (A) separate the inflow and outflow tracts of the right and left ventricles, respectively, and are parallel to one another. PV, pulmonary valve.

Mitral Valve

The mitral apparatus is comprised of the same five components as the tricuspid valve. Competent mitral valve function is a complex process that requires the proper interaction of all components, as well as adequate left atrial and left ventricular function. Abnormalities ofthe mitral valve apparatus may involve any of these components or combinations thereof. The pattern of pathologic involvement often determines the feasibility of mitral valve repair (surgical or percutaneous).18 The mitral valve annulus forms a complete fibrous ring that is firmly anchored along the circumference of the anterior leaflet by the tough fibrous skeleton of the heart17 (see -H 5 Fig. 2-21). Therefore, dilatation of the mitral valve annulus primarily affects the posterior leaflet. All current operative mitral repair techniques are based on this principle of asymmetric annular dilatation. Mitral valve annuloplasty reduces the mitral valve inlet area by reducing the circumference ofthe posterior leaflet.17 This is the rationale for using a partial posterior annuloplasty ring.

Unlike the other cardiac valves, the mitral valve has only two leaflets. The anterior leaflet is large and semicircular, and it partially separates the ventricular inflow and outflow tracts (see Fig. 223). However, unlike its right-sided counterpart, it also forms part of the outflow tract. In patients with hypertrophic obstructive cardiomyopathy, the anterior mitral leaflet may be drawn toward the basal anterior septum because ofthe Venturi effect, resulting in midsystolic outflow obstruction and mitral regurgitation.16 The posterior mitral leaflet is rectangular and usually is divided into three scallops. The middle scallop is the largest of the three in more than 90 percent of normal hearts. Occasionally, however, either the anterolateral or the posteromedial scallop is larger, and rarely there are accessory scallops15'17 (0+;0; Fig. 2-24, Plate 9). Posterior mitral leaflet prolapse usually involves the middle scallop and may be associated with chordal rupture. Both mitral leaflets are normally similar in area. The anterior leaflet is twice the height of the posterior leaflet but has half its annular length.17 With advanced age, the mitral leaflets thicken somewhat, particularly along their closing edges.15

The commissures are cleftlike splits in the leaflet tissue that represent the sites of separation of the leaflets (Figs. 2-25 and 0-H0; 2-26A). Beneath the two mitral commissures lie the anterolateral and posteromedial papillary muscles, which arise from the left ventricular free wall (see Figs. 2-18.5 and 2-25). Commissural chords arise from each papillary muscle and extend in a fanlike array to insert into the free edge of both leaflets adjacent to the commissures (major commissures)17 (see 0-»i0i Figs. 2-24 and 0+i0i 2-26^4, Plate 10) or into two adjacent scallops of the posterior leaflet (minor commissures) (see 0-H0i Figs. 2-24 and 2-25). In contrast to congenital clefts, a true commissure is always associated with an underlying papillary muscle and an intervening array of chordae tendineae.17 The attachments of commissural chords precisely demarcate the commissure. Because the commissural chords are seldom elongated, they serve as accurate reference points for determining the proper closing plane for the leaflets during surgical repair.

Views Mitral Valve Papillary Muscles

Figure 2-25: Gross anatomy of the mitral valve and papillary muscle-chordal apparatus, as demonstrated in an excised and unfolded valve. Each commissure overlies a papillary muscle. Arrows point to minor commissures. A, anterior leaflet; ALPM, anterolateral papillary muscle; P, posterior leaflet; PMPM, posteromedial papillary muscle.

Figure 2-25: Gross anatomy of the mitral valve and papillary muscle-chordal apparatus, as demonstrated in an excised and unfolded valve. Each commissure overlies a papillary muscle. Arrows point to minor commissures. A, anterior leaflet; ALPM, anterolateral papillary muscle; P, posterior leaflet; PMPM, posteromedial papillary muscle.

The anterolateral papillary muscle is commonly single and usually has a dual blood supply from the left coronary circulation.16 In contrast, the posteromedial papillary muscle usually has multiple heads and is most commonly supplied only by the right coronary artery.16 Small left atrial branches supply the most basal aspects of the mitral leaflets.17

Papillary muscle contraction pulls the two leaflets toward one another and thereby promotes valve closure. The line of closure for either mitral leaflet is not its free edge but an ill-defined junction between a thin, clear zone and a thicker, rough zone17 (see B-H0i Fig. 2-26, Plate 10). The major chordae supporting a leaflet insert into its free edge and rough zone. The chordae tendineae anchor and support the leaflets and, by doing so, prevent leaflet prolapse during ventricular systole. Two particularly prominent rough zone chords, referred to as strut chordae, insert along each half of the ventricular surface of the anterior mitral leaflet and provide additional leaflet support.17 They may contain cardiac muscle and tend to calcify with age. Unlike the tricuspid valve, the normal mitral leaflets have no chordal insertions into the ventricular septum.16

The functional orifice ofthe mitral valve is defined by its narrowest diastolic cross-sectional area. This may be at the annulus when there is extensive annular calcification or close to the papillary muscle tips in patients with rheumatic mitral stenosis.

Mitral valve prolapse is characterized by thickened and redundant leaflets, annular dilatation (with or without calcium), and thickened and elongated chordae tendineae (with or without rupture). Prolapse ofthe posterior leaflet occurs more frequently than that ofthe anterior leaflet. Rheumatic involvement ofthe mitral valve causes chordal shortening and thickening without annular dilatation. Rheumatic mitral stenosis is produced by chordal and commissural fusion, often with calcification, whereas rheumatic mitral insufficiency results from scar retraction of leaflets and chords.i5 Chronic postinfarction mitral regurgitation is associated with left ventricular dilatation and scarring of a papillary muscle and its subjacent ventricular free wall. Acute postinfarction mitral regurgitation may be associated with partial or complete rupture of a papillary muscle, usually the posteromedial one.

Anatomically important structures during mitral valve surgery include the left circumflex coronary artery, which courses within the left atrioventricular groove near the anterolateral commissure, and the coronary sinus, which courses within the left atrioventricular groove adjacent to the annulus of the posterior mitral leafletH (see Fig. 2-21 A).

Aortic Valve

The aortic valve, like the pulmonary valve, is comprised of three components (i.e., annulus, cusps, and commissures). In contrast to the mitral and tricuspid valves, the two semilunar valves have no tensor apparatus (i.e., chordae tendineae or papillary muscles). The commissures form tall, peaked spaces between the attachments of adjacent cusps (Figs. 2-27 and 2-28) and attain the level of the aortic sinotubular junction, the ridge that separates the sinus and tubular portions of the ascending aorta (originally described by Leonardo da Vinci as the "suprortic ridge")!5 (see Fig. 2-28). The functional aortic valve orifice may be at the sinotubular junction or proximal to it.17

Bicuspid Aortic Valve Gross Anatomy
Figure 2-27: Each cusp of a semilunar valve is pocket-shaped. The aortic valve is viewed from above in simulated closed (A) and open (B) positions, showing the three commissures (arrows). Note that the length of the closing edge exceeds the straight-line distance between the commissures.
Mitral Strut Chorda Cleft

Figure 2-28: An opened aortic valve shows the right (R), left (L), and posterior (P) cusps. The dashed line marks the closing edge. Between the free and closing edges of each cusp are two lunular areas, representing the surfaces of apposition between adjacent cusps during valve closure. The commissures (*) attain the level of the aortic sinotubular junction (STJ). Conus, conus coronary ostium; LC, left coronary ostium; LV, left ventricle; N, nodule of Arantius; RC, right coronary ostium.

Figure 2-28: An opened aortic valve shows the right (R), left (L), and posterior (P) cusps. The dashed line marks the closing edge. Between the free and closing edges of each cusp are two lunular areas, representing the surfaces of apposition between adjacent cusps during valve closure. The commissures (*) attain the level of the aortic sinotubular junction (STJ). Conus, conus coronary ostium; LC, left coronary ostium; LV, left ventricle; N, nodule of Arantius; RC, right coronary ostium.

The three half-moon-shaped (semilunar) aortic cusps form pocket-like tissue flaps that are avascular. In only about 10 percent of hearts are they truly equal in size. In two-thirds of hearts, either the right or posterior cusp is larger than the other two.17 Just below the free edge of each cusp is a ridgelike closing edge (see Fig. 2-28). At the center of each cusp the closing edge meets the free edge and forms a small fibrous mound, the nodule of Arantius15 (see Fig. 2-28). Between the free and closing edges, to each side of the nodule, are two crescent-shaped areas known as the lunulas that represent the sites of cusp apposition during valve closure.!5 Lunular fenestrations, near the commissures, are common and increase in size and incidence with age15 (Fig. 2-29). However, owing to their position distal to the closing edge, they rarely produce valvular incompetence.!7 When viewed from above, the linear distance along the closing edge of a cusp is much greater than the straight-line distance between its two commissures!5 (see Fig. 2-27). This extra length of cusp tissue is necessary for nonstenotic opening and nonregurgitant closure of the valve.15 Normally, the diameter of the aortic annulus at the hinge points of the aortic valve is about equal to the diameter of the ascending aorta at the sinotubular junction.8

Lunules Leonard Vinci
Figure 2-29: Aortic cusp fenestrations (arrows) occurring in the lunular regions near the commissures. This is a common age-related degenerative finding and normally accounts for little or no aortic valve regurgitation.

These are important anatomic details in patients undergoing aortic valve repair. In hearts from adults with bicuspid valves and other congenital aortic valve disease, the annular diameter is usually enlarged. In contrast, patients with normal aortic cusps and central aortic regurgitation show enlargement at the level ofthe sinotubular junctionX

A prebypass intraoperative transesophageal long-axis view ofthe left ventricular outflow tract is used to measure the aortic valve annular diameter prior to replacement by a homograft. By doing so, precious bypass time is saved while the homograft is being prepared.8 Disease processes that produce commissural fusion such as rheumatic valvulitis or which decrease cusp mobility such as fibrosis or calcification may lead to aortic stenosis.15 In contrast, those disorders which decrease cusp size such as rheumatic valvulitis or which cause aortic root dilatation may lead to aortic regurgitation.15 Combinations of these processes may produce combined stenosis and regurgitation.

The commissure between the right and posterior aortic cusps overlies the membranous septum (Fig. 2-30) and contacts the commissure between the anterior and septal leaflets of the tricuspid valve (see Fig. 2-40). The commissure between the right and left aortic cusps contacts its corresponding pulmonary commissure and overlies the infundibular septum (see 0-H0; Fig. 2-12D). The intervalvular fibrosa, at the commissure between the left and posterior aortic cusps, fuses the aortic valve to the anterior mitral leaflet.1517

Aortic Valve Commissure
Figure 2-30: The commissure between the right and posterior aortic cusps (arrow) overlies the transilluminated membranous septum (arrowhead). A, anterior mitral leaflet; Ao, ascending aorta; LV, left ventricle; P, posterior aortic cusp; R, right aortic cusp.

During aortic valve replacement, the anterior mitral leaflet, left bundle branch, or coronary ostia may be injured inadvertently.17 Annular abscesses due to infective endocarditis involving the aortic valve may burrow into adjacent structures and thereby produce endocarditis ofthe other valves, conduction disturbances with septal involvement, aortoatrial, aortopulmonary artery, or aortoventricular fistulas, pericarditis, or fatal hemopericardium.15

Pulmonary Valve

The pulmonary valve is virtually identical in design to the aortic valve.17 The pulmonary artery sinuses are partially embedded within the muscle bundles of the right ventricular infundibulum, particularly adjacent to the right and left sinuses.16,19 In pulmonary valve atresia with an intact ventricular septum, hypertrophy ofthe muscle bundles and the narrow right ventricular outflow tract accentuate this relationship.19 Also, unlike the aortic valve, which is continuous with the mitral valve, the pulmonary and tricuspid valves are separated by infundibular muscle.17

Age-Related Valve Changes

Several age-related changes in the cardiac valves may have clinical significance.20 In normal hearts, the thickness of the aortic and mitral leaflets increases progressively with each decade, particularly along their closure margins.20 Probably the most common clinical manifestation of these changes is aortic valve sclerosis, characterized by valve thickening without hemodynamic dysfunction.20 However, age-related degenerative calcification of an otherwise normal-appearing tricuspid aortic valve may result in progressive aortic stenosis.20

Age-related thickening along the nodule of Arantius and closing edges may be associated with the formation of whisker-like projections called Lambl's excrescences. These fine fibrous-like strands also can develop on the mitral valve.17 They are readily detected by echocardiography and have been associated with cardioembolic stroke.21 Larger clusters, having the appearance of a sea anemone, are considered to be either neoplastic or reactive and are known as papillary fibroelastomas.22

The circumferences of all four cardiac valves increase with age in normal hearts. This is particularly evident in the semilunar valves.20 Age-related annular dilatation of the aortic valve can result in aortic regurgitation.20 Mitral annular calcification is rare before age 70 but is present in 40 percent of women over age 90.20 Mitral annular calcification almost invariably only involves the posterior leaflet and forms a C-shaped ring of annular and subannular calcium.17 Mitral annular calcification may impede subannular ventricular contraction, thereby resulting in mitral regurgitation. Because ofthe proximity ofthe posteromedial commissure to the atrioventricular (His) bundle, mitral annular calcification may be associated with atrioventricular block.20 With the increasing size ofthe aging population, degenerative calcific aortic disease is increasing in frequency.20

Cardiac Grooves, Crux, and Margins

The atrioventricular groove encircles the heart and defines its base. It separates the atria from the ventricles (Fig. 2-31). The two ventricles are separated by the anterior and posterior (inferior) interventricular grooves, which define the plane of the ventricular septum (see Figs. 2-5^4 and 2-31).

Posterior Interventricular Sulcus

Figure 2-31: View of the diaphragmatic aspect of the heart shows the intersection of the atrioventricular (arrowheads), posterior interventricular (long arrow), and interatrial (small arrow) grooves at the external cardiac crux (*). (Left) Diagram. (Right) Cardiac specimen. LA, left atrium; LV, left ventricle; RV, right ventricle.

Figure 2-31: View of the diaphragmatic aspect of the heart shows the intersection of the atrioventricular (arrowheads), posterior interventricular (long arrow), and interatrial (small arrow) grooves at the external cardiac crux (*). (Left) Diagram. (Right) Cardiac specimen. LA, left atrium; LV, left ventricle; RV, right ventricle.

With age, fat tends to accumulate in increasing amounts in the epicardium, particularly in the atrioventricular grooves.2023 Increased epicardial fat deposits may be associated with increased risk of cardiac rupture after acute transmural myocardial infarction.23 Excess fat in the atrial septum is called lipomatous hypertrophy and may result in a thickness that exceeds that of the ventricular septum. Fat in the right ventricular free wall is difficult to detect accurately clinically; its excess accumulation may be associated with increasing age, obesity, or arrhythmogenic right ventricular cardiomyopathy.24

Along the surface of the heart, the right and circumflex coronary arteries travel in the right and left atrioventricular grooves, respectively, and the left anterior and posterior descending coronary arteries course along the anterior and posterior (or inferior) interventricular grooves, respectively (see Figs. 2-5^4 and 2-31). The external cardiac crux is the cross-shaped intersection between the atrioventricular, posterior interventricular, and interatrial grooves (see Fig. 2-31). Its internal counterpart (the internal crux) is the posterior intersection between the mitral and tricuspid annuli and the atrial and ventricular septa (see Figs. 2-16.B and 2-34, Plate

The junction between the anterior and inferior free walls of the right ventricle forms a sharp angle known as the acute margin. The rounded lateral wall of the left ventricle forms the obtuse margin.15

Right Ventricle

The right ventricle is a right-anterior structure. It is comprised of an inlet and trabecular and outflow segments15 (Fig. 2-32). The inlet component extends from the tricuspid annulus to the insertions of the papillary muscles. An apical trabecular zone extends inferiorly beyond the attachments of the papillary muscles toward the ventricular apex and about halfway along the anterior wall.15 This muscular meshwork is the site of insertion of transvenous ventricular pacemaker electrodes. During tight ventricular endomyocardial biopsy, tissue generally is obtained from the trabeculated apex. Disruption of a portion ofthe tricuspid support apparatus is a potential complication ofright-sidedheart instrumentation (e.g., right ventricular endomyocardial biopsy).17 The outflow portion, also known as the conus (meaning "cone") or infundibulum (meaning "funnel"), is a smooth-walled muscular subpulmonary channel15,17 (see Fig. 2-32).

Smooth Walled Infundibulum

Figure 2-32: Right ventricle. A. The right ventricular free wall has been removed to show the archlike crista supraventricularis, which consists of the parietal band (PB), infundibular septum (IS), and septal band (SB). The moderator band (*) joins the septal band to the anterior tricuspid papillary muscle (A). The anteroapical portion of the chamber is heavily trabeculated. M, medial tricuspid papillary muscle; PV, pulmonary valve; RAA, right atrial appendage; RCA, right coronary artery; TV, tricuspid valve. B. The right ventricle has been opened by the inflow-outflow method to show the parietal band (PB) separating the tricuspid and pulmonary valves, as well as the two upper limbs (arrows) of e septal band (SB). A, anterior leaflet of the tricuspid valve; P, posterior leaflet of the tricuspid valve; PT, pulmonary trunk; S, septal leaflet of the tricuspid valve; other abbreviations as in A.

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Responses

  • DARLENE
    What is the clinical significance of transverse pericardial sinus?
    7 years ago
  • David
    Which pericardial sinus clinically more important?
    6 years ago
  • Arja
    Why is transverse sinus is of surgical importance?
    3 years ago
  • Seija
    What is the clinical significance of transverse sinus of heart?
    3 years ago
  • miranda manna
    What is the clinical use of transverse and oblique groove in cardiac?
    3 years ago
  • Jimmy
    What is the clinical importance of the pericardial sinuses?
    3 years ago
  • Awet
    Why do surgeons use transverse pericardial sinus?
    3 years ago
  • Caden
    What is transverse sinus funtion in heart?
    3 years ago
  • Eino
    Why is surgically importance of coronary vessels are in epicardium?
    3 years ago
  • mary
    What is the use of transverse sinus of pericardium to surgen ?
    3 years ago
  • doda
    What is the clinical significance of crux of heart?
    3 years ago
  • cordelia
    Why surgeon use transverse sinus?
    2 years ago
  • ferumbras
    What is use of transverse sinus for cardiac surgeon?
    2 years ago
  • michael
    Why transverse pericardial sinus is important for cardiac surgeon?
    2 years ago
  • Sophia Scholz
    Why pericardial sinus is important for surgeons?
    2 years ago
  • Concetta
    Why is transverse pericardial important to cardiac surgeons?
    2 years ago
  • rodrick
    What will be posterior to transverse coronary sinus?
    2 years ago
  • gorbaduc puddifoot
    Why and how transverse sinus formed in heart?
    2 years ago
  • KAROLIINA
    What is the significance of the sinuses of the pericardium?
    1 year ago
  • richard hamilton
    What is surgical significance of transverse pericardial sinus?
    1 year ago

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