Valvar Structures Research Articles

Severe form of the hydrothorax associated with right divided atrium and Cytomegalovirus infection - Prenatal diagnosis and outcomes

Abstract
 Fetal hydrothorax (FH) or pleural effusion is a clinical entity, and refers to accumulation of fetal pleural fluid, which may presents a wide spectrum of severity ranging from small, harmless effusion, to life-threatening thoracic compression (1). The perinatal mortality associated with pleural effusion is at least 50 %. Cardiac and extra-cardiac abnormalities may accompany the hydrothorax and their presence also affects the prognosis (2).
 Division of the right atrium, first reported in 1868, also known as cor triatriatum dexter, is extremely a rare congenitally abnormality, in which persistence of right valve of the embryonic systemic venous sinus divides the right atrium into two chambers. The embryonic valvar structures, whose significance during fetal life is to direct the richly oxygenated inferior caval venous blood across to the left atrium and thence to the aorta, normal regress in late fetal life and early childhood.
 Cytomegalovirus (CMV) is a common human virus, member of herpes virus family, and the most common cause of intrauterine infection, occurring in 0.2 % to 2.2 % of life births (3,4). This report describes antenataly diagnosed a case of a divided right atrium, associated with severe form of hydrothorax and Cytomegalovirus infection.
 Here we present a fetus with sever hydrothorax associated with divided right atrium and cytomegalovirus infection.

Knowing Real Cardiac Anatomy Enhances Understanding of Virtual Anatomy

Present day advances in cardiac imaging, both clinically and with embryonic development, demonstrate the need for promoting attitudinally appropriate positioning of the heart in the dissection lab and with respect to the nomenclature of the cardiac structures. One of the first rules of anatomy is that all structures within the body should be described as viewed in the so‐called anatomical position. The true details of cardiac development are now being confirmed through the use of three dimensional imaging technology and can be directly correlated with the fully developed heart. In order to correlate the anatomic features depicted by actual dissection with the ever advancing imaging techniques, the anatomic details of the heart itself must be accurate. In the dissection lab, the heart is initially viewed within the thoracic cavity, but once removed it is typically assessed in the so‐called Valentine position. This no longer correlates with the clinical images or the actual position of the cardiac structures when viewed in their appropriate anatomic positon. The many nuances of cardiac anatomy can now be effectively taught using direct comparison between virtual and real dissection with both techniques allowing for adequate examination of the cardiac segments. Each of the cardiac segments and their junctions can then be assessed in their own right for their intrinsic anatomic features.The long axis of the heart lies roughly at a 45 degree angle to the long axis of the spine. The position of the ventricles extends from right posterior to left anterior with the so‐called right‐sided structures actually lying anterior to those described as being left‐sided. The aortic root forms the center piece of the heart and this is demonstrated well with virtual dissection. Of necessity, demonstrating this by physical dissection requires the removal of those structures located anterior to the aortic root, namely, portions of the inner heart curvature, subpulmonary infundibulm and pulmonary trunk. Once removed, the structures cannot be replaced as they can with virtual dissection. The three segments of the heart are the atriums, the ventricles and the arterial trunks, with valvar structures guarding the junctions between the segments. Developmentally it has now been demonstrated that there are two ‘true’ components making up the atrial septum. These septal structures are largely surrounded by folds that are now easily appreciated with the use virtual dissection techniques. Learning the component parts of the atriums, their appendages, true septums and interatrial folds is of high clinical significance with the development of new interventional procedures. The relationships at the atrioventricular and ventriculo‐arterial junctions are easily documented and compared between the two dissection techniques. Analysis of the cardiac segments is now performed via virtual dissection just as well, if not better than in the dissection lab.

Quasi monospecific proliferation of Pteroncola inane (Giffen) Round (Fragilariales; Bacillariophyceae) on blades of Eisenia arborea Areschoug.

The arraphid diatom Pteroncola inane is a taxon that commonly inhabits the feathers of seabirds and as an epiphyte on European coasts, but until now it was not registered for the coasts of Mexico. In this study, proliferations of P. inane are recorded on sheets of Eisenia arborea collected in Bahía Magdalena Baja California Sur, Mexico, where it was the dominant taxon den another of the epiphytic diatom association that included 75 taxa; most of these rare and rare. In fresh preparations the specimens showed two chloroplasts parietal laminar; no type was observed of cologne. In permanent preparations P. inane presented hyaline appearance, absence of valvar structure and points along the margins of the valvar mantle. The identification of this taxon was achieved by means of scanning electron microscopy (SEM), with which the striae of the valves and a barely perceptible narrow sternum were observed. Likewise, it was noted that the marginal points consist of perforations of the first intercalary band and that it exhibits thickening of the valvar mantle as points. This constitutes the first record of P. inane for Mexico and the first as an epiphyte in a benthic environment for the eastern Pacific.

New imaging modalities in the catheterization laboratory

To provide an overview of the various modalities that have emerged in the last years as adjunctive tools to provide detailed imaging of the cardiovascular system in the catheterization laboratory. Completion angiography after cardiac surgery for congenital heart disease using a dedicated hybrid operating cardiac suite may aid in early diagnosis and therapy of postsurgical abnormalities. The application of three-dimensional rotational digital angiography results in a more precise delineation of the three-dimensional anatomy of vascular structures outside the heart with rapid image processing and reduction of the amount of contrast used and ionizing radiation dose. Combined catheterization/magnetic resonance (MR) hybrid laboratories have the potential to accurately assess changes in the anatomy and physiology pretranscatheter and posttranscatheter interventions. Fully MR-guided transcatheter procedures have become possible in animal models. Real-time three-dimensional transesophageal echocardiography (TEE) has helped to guide transcatheter procedures in septal and valvar structures. Miniaturization of probes has expanded the applications of TEE for smaller neonates. The use of intravascular ultrasound has helped to better understand the mechanisms of vascular diseases and transcatheter treatments. Knowledge and proper application of new imaging modalities during interventions in the catheterization laboratory may improve the outcomes of patients with congenital and acquired structural heart disease.

A method for standardized computed tomography angiography-based measurement of aortic valvar structures

Reliable assessment of the aortic valvar apparatus (AVAp) is essential as it may facilitate consistent outcomes with percutaneous aortic valvar therapies. The commonly referenced aortic annulus is problematic since this measurement does not correspond to any actual anatomic structure. We aim to describe a reliable method of measuring relevant structures of the AVAp based on widely available computed tomography analyses. Retrospective analysis of computed tomograms of 75 patients with severe aortic stenosis (45 females, age 81.2 +/- 7.8 years). Curved multiplaner reconstruction technique was used to measure average diameters of the 'Aortic Leaflets Basal Attachment Plane' (ALBAP), sinuses of Valsalva (SV), sinutubular junction (STJ), ascending aorta (AA), and distance from coronary arteries to the base of the cusps. Angulation between the AA and the left ventricle (LV) was measured in one plane that included the LV inflow long axis and the maximum visualization of the aortic root. Inter-rater reliability and absolute agreement among three raters were evaluated. Intra-class correlation coefficients for ALBAP, SV, STJ, and AA diameters were 0.90, 0.99, 0.95, and 0.94, respectively (P < 0.001) with 95% limits of agreement of the observed differences falling in the less than 1 mm range. Intra-class correlation coefficients were 0.82 for the angle and 0.61 and 0.78 for distances to the right and left coronary arteries (P < 0.001). This method showed a high degree of inter-rater reliability and absolute agreement for AVAp diameters. Agreement was lower for AA-LV angle and distance to coronary artery measurements, emphasizing the need for software improvements and standardized image acquisition protocols.

Is the Morphologic Mitral Valve in Discordant Atrioventricular Connections Always Normal?

The purpose of this study was to determine structural features and variations in the mitral valve guarding inflow of the morphologic left ventricle in hearts with discordant atrioventricular connections. Morphologic investigation was carried out on the inlet valve to the morphologic left ventricle in 48 autopsied specimens with this particular entity of malformation. The tension apparatus was straddling to the morphologic right ventricle in 2. Another 34 hearts had a bifoliate valve and the papillary muscles abnormally oriented; a solitary papillary muscle in 3, two papillary muscles but deviated in 5, one of two papillary muscles being dysmorphic in 9, and three or more papillary muscles in 17. The origin of these papillary muscles was frequently deviated. In 5 hearts with a trifoliate or quadrifoliate valve, multiple papillary muscles were also the case. One of these had thick leaflets, a part of which was adherent to a membranous flap around the ventricular septal defect as well as to subpulmonary fibrous tissue tags. Eventually, the valve was comparable with the mitral valve seen in the normally structured heart in only 7 hearts (15%). There was no obvious correlation noted between the presence of abnormality in the mitral valve and that in the tricuspid valve. Architectural abnormalities are not rare in the morphologic mitral valve in this setting. The valvar structure needs precise recognition.

The larva and female of Rhyacophila fonticola Giudicelli & Dakki, 1984 (Trichoptera: Rhyacophilidae), an interesting Betic–Rifean endemic species

The female and last instar larva of the hitherto unknown Betic–Rifean species Rhyacophila fonticola Giudicelli & Dakki, 1984 are described and figured for the first time. Some notes on male variability and ecological preferences of this species are also included. The female is clearly different from that of the remainder species of the vulgaris group in the valvar structure of segment VIII. The larva belongs to the “Pararhyacophila group”, but an unusual character makes this species unique within this group: there are two gill tufts on each side of the first abdominal segment. This character makes the larva of R. fonticola clearly different from the remaining known Iberian species.

Relation between cardiovascular risk factors and nonrheumatic severe calcific aortic stenosis among patients with a three-cuspid aortic valve

Valvular aortic stenosis (AS) caused by degenerative calcification of the valvar structures has become the most common valvar disease requiring cardiac surgery in industrialized countries. Roberts1 suggested as early as 1986 that factors predisposing to atherosclerosis in the coronary arteries also predispose the aortic valve to calcification in the elderly. Previous clinical studies reported that atherosclerotic risk factors associated with AS could vary with the etiology.2,3 To our knowledge, no data are available in patients with exclusively severe calcific degenerative AS. This prospective study, controlled for age and sex, was designed to examine the specific relation between the presence of severe calcific degenerative AS and cardiovascular risk factors.

Anatomy of Atrial and Ventricular Septal Defects

The anatomy of atrial and ventricular septal defects is reviewed with reference to the normal cardiac septum. Owing to the limited extent of the atrial septum, true septal defects are confined to the area of the oval fossa. The sinus venosus and coronary sinus defects are interatrial communications being outside the confines of the atrial septum and close to important atrial structures. The description of ventricular septal defects as perimembranous, muscular and doubly committed, and juxtaarte rial defects highlights the anatomy of the margins, the location, and proximity to the conduction system and valvar structures. Malalignment of septal structures can complicate the anatomy of ventricular septal defects producing inlet or outlet obstruction.

Echocardiography

Echocardiography uses very high frequency sound waves (ultrasound), which are inaudible to human ears. Sound waves are forms of pressure wave; they can travel through any medium. In echocardiography these...

Intraoperative transesophageal echocardiography for pediatric patients with congenital heart disease.

Intraoperative transesophageal echocardiography for pediatric patients with congenital heart disease.

Accessory and anomalous atrioventricular valvar tissue causing outflow tract obstruction: surgical implications of a heterogeneous and complex problem.

The purpose of this study was to determine the effect of accessory or anomalous atrioventricular valvar apparatus on relief of outflow tract obstruction. Outflow tract obstruction due to accessory tissue or anomalous attachments of the atrioventricular valvar apparatus is an unusual but well-recognized problem. In addition to obstruction, anomalous attachments of the atrioventricular valvar apparatus may interfere with procedures to relieve outflow tract obstruction or perform outflow tract reconstruction. Since 1992, we have operated on 21 patients (median age 4 years) with systemic (n=13), pulmonary (n=5) or bilateral (n=3) outflow tract obstruction due to accessory atrioventricular valvar tissue and/or anomalous attachments of the subvalvar apparatus. Primary diagnoses were isolated obstruction of the systemic outflow tract or aortic arch (n=7), transposition complexes (n=6), previously repaired atrioventricular septal defect (n=3), functionally single ventricle (n=3) and ventricular septal defect with pulmonary outflow obstruction (n=2). Outflow tract gradients ranged from 20-110 mm Hg (median 58 mm Hg). Complete relief of obstruction due to atrioventricular valvar anomalies was possible in 14 patients. In six patients, the planned procedure either had to be modified or only partial relief of the obstruction was achieved. In the remaining patient, who had borderline functionally single ventricle heart disease (unbalanced atrioventricular septal defect) and systemic outflow obstruction due to accessory and functional valvar apparatus, support was withdrawn because the parents refused univentricular palliation and the valvar anomalies precluded a Ross-Konno procedure. There were two early deaths. At follow-up ranging from 1 to 66 months (median 27 months), there was one death, and there has been no recurrence of outflow tract obstruction or residual atrioventricular valvar tissue. Outflow tract obstruction caused by accessory or anomalous atrioventricular valvar structures is an uncommon and heterogeneous group of conditions that can have significant surgical implications. In the majority of cases, tailoring of surgical techniques will permit complete relief of obstruction. However, such anomalies may limit standard surgical options and necessitate an innovative approach in some patients.

The surgical treatment of Ebstein's malformation

THE MOST APPROPRIATE SURGICAL TREATMENT FOR Ebstein's malformation and, indeed, the very nature of the lesion itself, remain contentious issues. The long experience of the group from Hopital Broussais has proved invaluable in directing surgeons towards the best techniques for conservative repair and in pointing anatomists towards the most appropriate description of the deranged valvar structure. This is exemplified by the advances made in the understanding of the left atrioventricular valve in hearts with deficient atrioventricular septation (atrioventricular canal malformations) . It was the beautifully explicit diagrams of Carpentier which, for me at least, first focused attention on the unequivocal trifoliate arrangement of this left atrioventricular valve, although the information required was also provided by Van Mierop and his colleagues in their earlier studies.' The impact of all these excellent investigations, however, was dissipated by continued use of the adjective mitral to describe the trifoliate valve, together with arguments which continued concerning the optimal surgical treatment of the zone of apposition between the edges of the two leaflets of the trifoliate valve which bridge the ventricular septum (the commissure or cleft). It is now becoming appreciated that it is better to avoid nominative terms for this structure and simply describe the zone of apposition between the leaflets. In the accompanying paper, Chauvaud and his colleagues describe the continuing evaluation of their surgical management of Ebstein's malformation. At the same time, (for me, at any rate) they continue to clarify the morphology of this fascinating lesion. I had thought that I understood well the anomaly, having published several accounts of its structure which, over time, illustrated my own increasing appreciation of its morphology. When preparing a chapter from a presentation for a meeting also attended by both Chauvaud and Carpentier, however, elements of my continuing ignorance were highlighted by the comments of these skilled surgeons. Much of the impetus for my own chapter had itself been provided by an editorial comment by Becker

Le genre Gomphoneis (Bacillariophyta) : un nouveau modèle d'organisation du cingulum

The valvar structure and the cingulum arrangement of a diatom related to the Gomphoneis herculeana – Gomphoneis minuta complex were investigated in electron and light microscopy. Ultrastructural features include striae composed of double rows of areolae, apical pore fields composed of pores structurally differentiated from the areolae and the presence of an axial siliceous plate responsible for longitudinal lines visible in light microscopy. The pars interior of the valvocopula looks like a marginal lamina of silica. A new model of organization for the cingulum, quite different from the classical model, is proposed. The valvocopula is a closed band with a connective septum at both the head and the footpole. The copulae, each of them with a connective septum, are open bands, with their openings at opposite poles. All septa possess on the advalvar face a projecting lamina that fits under the pseudosepta of the valve or the septum of a girdle band. The first two copulae are directly connected with the opposite septa of the valvocopula. The third copula is attached to the first copula and the fourth to the second. Key words: Bacillariophyta, Gomphoneis, valve, model, cingulum.

Reconstruction of the mitral valve in children— long-term follow-up in 63 cases

SummaryBetween June 1985 and June 1991, 63 children underwent surgical reconstruction of the mitral valve for rheumatic (46 cases), congenital (12 cases) and myxoid (five cases) disease. The ages ranged from two to 18 years (mean 14.1±3.7 years). Valvar dysfunction was classified according to its pathophysiological abnormalities. A group of four cases presented with regurgitation secondary to lesions located in the valvar structures but with normal motion of the leaflets. In a second group of 14 cases, mitral regurgitation was due to prolapsed leaflets because of lesions located mainly in the subvalvar structures. A third group was formed by 35 patients with mitral regurgitation with restricted motion of the leaflets due to lesions in the valvar and subvalvar structures. The final group, of 10 cases, presented with mitral stenosis. The overall surgical mortality rate was 4.7% (3/63), and follow-up data were available in all survivors from one to 96 months (mean 33.4±25.4). Four cases underwent reoperation due to residual incompetence, one case due to bacterial endocarditis, and two more are scheduled for replacement of the valve due to unfavorable evolution, giving an overall rate of reoperation of 4.3% per patient/year. One patient died in the period following valvar replacement (late mortality rate of 0.6% per patient/year). Thromboembolism occurred in four cases in the absence of anticoagulation; three of them were in atrial fibrillation (late thromboembolic rate 2.4% per patient/year). Prior to surgery, 28 cases were in functional class II of the New York Heart Association, 34 patients were in class III and one patient in class IV. At the end of the follow-up period, 49 patients were in class I, seven in class II and four in functional class III (p&lt;0.0001). The cardiothoracic ratio before surgery ranged from 0.40 to 0.81 (mean 0.60±0.07) and, after surgery, the values ranged from 0.40 to 0.79 (mean 0.55±0.07) (p&lt;0.0001). Randomized late echocardiographic evaluation in 24 cases revealed residual mild mitral regurgitation in 20 cases, moderate in two and severe in two. The latter are scheduled for valvar replacement. There were no significant differences in the surgical results among the four groups. Reconstruction of the mitral valve, therefore, provides stable functional results with low surgical and late mortality, as well as an acceptable rate of reoperation irrespective of the lesions of the valvar apparatus.

AMPHORA TUCUMANASP. NOV., A NEW SPECIES FROM CUMBRES CALCHAQUÍES, TUCUMÁN, ARGENTINA

Amphora tucumana sp. nov. is described from bottom sediments of the Laguna Nostra (Cumbres Calchaquis, 4300 m altitude, Tucuman province, Argentina). Its valvar structure is described, using LM and SEM. The principal characteristics of the species are its transapical costa-like internal thickenings, the raphe-ledge covered by small and irregular depressions, and its areolae of irregular length. Its relationships are discussed.

PLACONEISMERESCHKOWSKY: THE RE-EVALUATION OF A DIATOM GENUS ORIGINALLY CHARACTERIZED BY ITS CHLOROPLAST TYPE

Several freshwater naviculoid diatoms, for which Mereschkowsky erected the genus Placoneis, have been re-examined with light and electron microscopy. The findings reveal that, in addition to their distinctive chloroplast type, their valvar structure also differs significantly from that of Navicula sensu stricto, and their separation from the latter is warranted. Placoneis is therefore re-erected to include them and an emended description and generitype are given. Some species included by Mereschkowsky have however been excluded, while other, more recently described taxa have been transferred to Placoneis. The position of a number of species remains unclear. Some of the taxonomie and nomenclatural problems associated with this group are briefly discussed.