Usual Arrangement Research Articles

Obstructed total anomalous pulmonary venous connection

With the advent of echocardiography, total anomalous pulmonary venous connection (TAPVC) can be readily diagnosed without much difficulty. However, noninvasive detection of the presence of pulmonary venous obstruction in TAPVC remains a difficult issue. During a 5.5-year period, 42 patients were found to have TAPVC by catheterization, surgery, and/or autopsy: 17 had supracardiac drainage, 13 paracardiac drainage, nine infracardiac drainage, and three mixed drainage. Obstruction to pulmonary venous drainage was found in 24 patients (57%). Patients with right isomerism tended to have a higher incidence of pulmonary venous obstruction than those with the usual atrial arrangement (80% vs. 44%, p < 0.05). Color Doppler combined with cross-sectional echocardiography provided accurate delineation of drainage sites in 93% cases (39 of 42). Among the 39 cases with correct echocardiographic delineation of the drainage site, obstruction was detected by echocardiography in 22 cases with a sensitivity of 100% (22 of 22) and a specificity of 85% (17 of 20). Therefore, complete echocardiography, including cross-sectional images and color Doppler proved to be a reliable tool in the detection of drainage sites and pulmonary venous obstruction in TAPVC.

Common variations in muscles and tendons of the human hand

AbstractCommon variations in muscles and tendons of the hand were determined by dissecting 40 pairs of hands (20 male, 20 female). Contrary to some anatomy textbooks which describe only three palmar interossei, with the thumb lacking one, this study found four palmar interossei present in 85% of hands and 90% of bodies. This first palmar interosseous typically arose from the base of the first metacarpal and inserted along with the tendon of the oblique head of adductor pollicis into the base of the proximal phalanx. Forty hands (50%) did not have the usual arrangement of lumbricals. Twenty‐seven (34%) third lumbricals and four (5%) fourth lumbricals split at their insertions; four third lumbricals and four fourth lumbricals inserted on the ulnar side of the middle and ring fingers, respectively. The abductor pollicis longus inserted by 2 or 3 tendons in 91% of hands. The tendon of extensor digiti minimi split into 2 or 3 slips in practically all of the hands studied (96%). The tendon of extensor indicis split into 2 slips in more than a third (38%) of hands. In almost a third (30%) of hands there were accessory extensor muscles present deep to the tendons of extensor digitorum. Lastly, extra slips of origin of the abductor digiti minimi were present in 10% of hands. This study confirms the presence of a palmar interosseous muscle for the thumb and demonstrates that some variations occur more frequently than was expected. © 1993 Wiley‐Liss, Inc.

Discordance between abdominal and atrial arrangement in a case of complex congenital heart disease

The report describes a rare case of a complex congenital heart disease wherein the splenic status and the relationship of the suprarenal abdominal great vessels strongly suggested right isomerism, but atrial morphology demonstrated usual atrial arrangement. It emphasises the increasing recognition that the arrangement of the abdominal organs need not accurately reflect atrial arrangement.

Abnormal laterality and congenital cardiac anomalies. Relations of visceral and cardiac morphologies in the iv/iv mouse.

In the management of hearts with deranged laterality, it is essential that the left and right atrial chambers are correctly identified. There are two major approaches, which are based on venous connections or on the morphology of the atrial appendages, and there is no consensus as to which is the most useful. We used the iv/iv mouse mutant, which is known to be pertinent to this problem, to evaluate the relations of cardiac defects with atrial, venous, and other visceral morphologies. The morphology of the heart and other organs was examined in 275 iv/iv mice using criteria based on abnormal laterality in humans. The arrangement of the atrial appendages was determined by morphological examination of the junction between the appendage and the venous component of the atrium. On this basis, 45.1% of cases were shown to have usual atrial arrangement, 50.2% had mirror imagery, 1.5% had right isomerism, and 3.3% had left isomerism. Every case of atrial isomerism had a cardiac lesion; the morphological types were similar to those seen in human cases. Of cases with either usual or mirror-image arrangement of the appendages, 33.2% had abnormal spleens, but only 3.1% had cardiac defects. Similarly, venous abnormalities were much more common (30.1%) than cardiac defects. Study results endorse the importance of the morphology of atrial appendages in predicting cardiac abnormalities and point to the marked inconsistency of the arrangement of other organs, including the spleen and the connections of the systemic veins.

Intermediate-term survival and functional results after arterial repair for transposition of the great arteries

An assessment of late morbidity and mortality is essential before arterial repair can be considered truly corrective for patients with transposition of the great arteries. We describe the early and intermediate-term results in 126 patients who underwent arterial repair. Operation was performed at a median age of 6 days, with 76 patients operated on within the first 7 days of life. Coronary artery anatomy differed from the usual arrangement in 37 patients. Simultaneous procedures included ventricular septal defect closure (35) and repair of interrupted aortic arch (2) or coarctation (5). Hospital mortality was seven of 126 (5.5%), with three deaths among the most recent 100 patients (3%). There were one late, noncardiac death and one late death after reoperation. Reoperation for pulmonary artery stenosis was required in 10 of the first 63 patients (16%), all of whom underwent pulmonary artery reconstruction with separate patches for closure of the coronary excision sites. Of the last 63 patients, all of whom underwent pulmonary artery reconstruction with a single pantaloon-shaped pericardial patch, one (2%) required reoperation for pulmonary artery stenosis. Doppler flow studies and echocardiography performed in 115 of 119 surviving patients at a mean of 12 months after repair demonstrated normal left ventricular function, minimal left ventricular outflow gradients, and no more than trivial aortic regurgitation. Peak gradient across the right ventricular outflow tract was 19 +/- 3 mm Hg in patients with separate pulmonary artery patches and 5 +/- 2 mm Hg in those with a single pantaloon patch (p = 0.0001). Follow-up is 96% complete from 1 month to 8 years after operation (mean 2.5 years). The actuarial survival rate at 5 years, including operative mortality, was 92%. All patients are in sinus rhythm, and none requires antiarrhythmic medications. These data suggest that pulmonary artery reconstruction with a single pantaloon patch may be associated with a decreased requirement for reoperation. Intermediate-term survival and functional results are excellent after arterial repair for transposition of the great arteries.

Palladium(II) complexes of 1,4-benzodiazepines. Crystal structure and reactivity in dimethylsulphoxide of [Pd(bromazepam)Cl 2

The crystal structure of the title complex has been determined from single crystal X-ray data. The palladium atom is in the usual square planar arrangement with 7-bromo- 1,3-dihydro-5-(2-pyridyl)-2H-1,4-benzodiazepine-2-one (bromazepam) coordinated with the two α-diimine nitrogen atoms of bromazepam and two cis-chlorine atoms. The geometry of the molecule and its crystal packing are similar to the corresponding platinum(II) complex, where the usual boat conformation of bromazepam is retained. The kinetics of displacement of coordinated bromazepam, by 1,10-phenanthroline and 2,2′-bipyridine, in [Pd(bromazepam)Cl 2] have been studied by stopped-flow spectrophotometry in dimethylsulphoxide at 25°C. The data have been interpreted in terms of a mechanism implying two reacting forms, the complex and a solvo-species with mono-coordinated bromazepam. In the case of the less reactive bipyridine, ring closure of bromazepam and entry of the nucelophile compete for the reaction centre.

The surgical anatomy of double-outlet right ventricle with concordant atrioventricular connection and noncommitted ventricular septal defect

In describing hearts with double-outlet right ventricle, we have had problems with how best to use the term noncommitted as applied to the ventricular septal defect. We reviewed, therefore, 63 hearts with double-outlet right ventricle in the setting of usual atrial arrangement and a concordant atrioventricular connection. From these, 18 hearts with potentially noncommitted defects were identified and studied in detail. The defect was unequivocally remote from the ventricular outflow tracts in 16 of these hearts, being perimembranous with excavation to open into the inlet of the right ventricle in 12, two of these also having straddling of an atrioventricular valve. One heart had a muscular defect situated in the inlet part of the muscular septum, whereas the defect was the ventricular component of an atrioventricular septal defect in the other three. In the remaining two hearts the defect was anatomically juxtaposed to a subarterial outlet. The pathway to the outflow tract, however, was obstructed by leaflets of a straddling valve. Our study shows, therefore, the need to distinguish between anatomic "commitment" of the defect from the problems in terms of commitment that may confront the surgeon in the operating room. Not only does the distance between the interventricular communication and one of the subarterial outflow tract need to be assessed (the anatomic commitment), but also the presence and nature of any intervening extraneous tissues (the surgical commitment) requires assessment.

Atrioventricular septal defect in fetal life—a clinicopathological correlation

SummaryIn a series of over 7,000 pregnancies referred for fetal echocardiography, atrioventricular septal defects were detected in 103 fetuses, (17% of 594 anomalies). A large proportion (42%) also had isomerism of the atrial appendages, abnormalities in arrangement and morphology of the thoracoabdominal organs, and a high incidence of associated cardiac malformations. When this was associated with abnormalities of rhythm, the fetus often showed signs of intrauterine congestive heart failure; hydrops, pleural effusion and ascites. Those with trisomic karyotypes (predominantly trisomy 21) were associated with usual atrial arrangement and concordant connections of the cardiac segments. Of the 103 fetuses, 53 were examined at autopsy. Extracardiac abnormalities were documented, and detailed morphologic examination and measurements of the heart were made. The ratios of inlet to outlet septal disproportion were not significantly different from those found in postnatal hearts. Again, as in postnatal life, those hearts with common atrioventricular orifice had a greater degree of ‘scooping’ of the ventricular septum compared to those with separate right and left atrioventricular valves. There were no significant differences in these findings in relation to the karyotype of the fetus. There was an increased incidence of ventricular dominance, and also of coarctation or hypoplasia of the aortic arch, in fetal hearts when compared to autopsied hearts obtained in postnatal life. In summary, the distinguishing morphological characteristics of atrioventricular septal defect are present from 16 weeks of gestation.

Atresia of the left atrioventricular valve with patency of the aorta: anatomico-functional analysis of 23 patients

We analyzed the findings in 23 patients with atresia of the left atrioventricular valve and a patent aorta seen in the period from January 1980 to July 1989. Having divided the cases according to the anatomical findings, we made a subsequent analysis of the clinical and surgical results with the aim of establishing the management most likely to diminish risks, still high, in treatment of this complex anomaly. From the anatomical viewpoint, three variants were observed. In the first, made up of 15 cases, there was absence of the left atrioventricular connexion. The characteristic finding in the second group, with five cases, was an imperforate left atrioventricular valve in the setting of concordant atrioventricular connexions. The third group, of these cases, was dominated by the presence of isomerism of the atrial appendages, both appendages being of left morphology in one case, and of right morphology in the other two. Further anatomical variation was then found in each group. Nine of the 15 with absence of the left atrioventricular connexion had the right atrium connected to a dominant left ventricle in presence of a rudimentary and incomplete right ventricle associated with discordant ventriculo-arterial connexions, all of them being in usual atrial arrangement and three with pulmonary stenosis. The remaining six in this first variant had the right atrium connected to a dominant right ventricle. In the five patients with imperforate left atrioventricular valves, two had discordant and three had concordant ventriculo-arterial connexions. In the three cases with isomerism, two had absence of the left atrioventricular connexion, with a dominant right ventricle. The last patient had an imperforate left atrioventricular valve and a discordant ventriculo-arterial connexion. From the functional viewpoint, there were 14 patients (10 with absence of an atrioventricular connexion, four with imperforate atrioventricular valve) with congestive heart failure and nine patients (five from the first, one from second, and three from the third variant) with hypoxia. Long-term follow-up (median 16.4 months — varying from 1 to 41 months — in the group with congestion and 27.7 months — varying from 12 to 57 months — in those with hypoxia) showed favorable clinical evolution in 11 (91%). We conclude that an anatomico-functional division can point towards the most appropriate management in this complex anomaly.

A Microgenetic Study of the Müller-Lyer Illusion

In two experiments a decomposed Müller-Lyer pattern was used to measure the time course of the illusion. A partial report procedure was used to prevent the subjects from focusing only on parts of the pattern and to maximize visual processing. The Müller-Lyer figure was decomposed into two parts, its angles and its line. A configuration of three pairs of angles, each corresponding to a row in the usual partial report arrangement, was used. A line that did or did not fit the gap was shown with a variable delay (interstimulus interval, ISI). By this procedure the relevant row (line gap) was cued. The subject had to decide whether the line fitted or was too short/long. Two exposure times for the angles were used, 50 or 200 ms in one experiment and 50 or 500 ms in the other. The result of the first experiment, with outward-pointing fins, was a stable illusion for all values of ISI (25-400 ms) and all exposure times, with one significant exception: exposure for 50 ms with an ISI of 50 ms yielded an illusion peak. It was shown that this was not caused by a reduction in length-discrimination performance. In the second experiment, with inward-pointing fins, no such peak occurred. There was only a tendency for the illusion to vanish with zero ISI. The results are discussed with respect to 'global to local' theories of visual processing.

Discordant atrioventricular connexion with concordant ventriculo-arterial connexion (so-called “isolated ventricular inversion”) with usual atrial arrangement (situs solitus)

The combination of a discordant atrioventricular connexion with a concordant ventriculo-arterial connexion (so-called “isolated ventricular inversion”) is an extremely rare entity described, to the best of our knowledge, on only 15 occasions in patients with usual atrial arrangement. Initial diagnosis at cross-sectional echocardiography has only been reported three times, but the combination has been diagnosed in life on seven occasions, with successful Mustard or Senning operations having been performed in six of these patients. We report a neonate referred with an initial diagnosis of complete transposition, who was correctly diagnosed at cross-sectional echocardiography, and had closure of an associated ventricular septal defect with a Senning procedure in the neonatal period.

Buying a dental practice: the legal and commercial issues. Part 1

There is much mystique surrounding the acquisition by a young practitioner of his or her first dental practice, arising largely from his fear of the unknown. In fact, provided that he or she obtains sound legal and commercial advice, he or she can purchase a dental practice almost exclusively out of borrowed capital. Whilst repaying capital (and interest) over a 10-year period, it is possible to earn more from day one than as a relatively experienced associate on the usual commission arrangement.

Input-output stability of sampled-data systems

The authors study the L/sub p/ input-output stability of a continuous-time controller, using the usual arrangement of periodic sampling and zero-order hold. It is noted that even if the hybrid system is exponentially stable, this arrangement does not yield L/sub p/ (1<or=p< infinity ) stability in general. It is shown that this problem can be alleviated if a strictly causal stable continuous-time filter (e.g. antialiasing filter) is introduced prior to the sampler. For various configurations, L/sub p/ stability is examined in connection with exponential stability.<<ETX>>

The assessment of juxtaposed atrial appendages by transoesophageal echocardiography

As part of a prospective study into the diagnostic role of transoesophageal echocardiography in children with complex congenital heart disease, the atrial morphology was assessed in 62 children. Using the direct visualization of atrial appendage morphology, 58 were shown to have usual atrial arrangement, two were documented to have isomerism of the right and two isomerism of the left appendages. Of those with usual arrangement, four children were demonstrated to have left juxtaposition of the atrial appendages. Only two of these patients were identified during praecordial echocardiographic re-evaluation, and three on angiocardiographic examination. Surgical confirmation was obtained in three, and juxtaposition was excluded in the remaining cases. The transoesophageal cross-sectional imaging features of left juxtaposition of the atrial appendages are unique and readily diagnostic of this entity. They include, first, a lateral deviation of the mid-portion of the atrial septum and, second, a frontal orientation of the antero-superior portion forming the floor and the posterior wall of the junction of the right-sided atrial appendage with the venous component of the atrial cavity. The knowledge of these morphologic characteristics is important, as, otherwise, this malformation may be misinterpreted as representing an atrial septal defect. The results suggest that transoesophageal echocardiography will be the most sensitive preoperative diagnostic technique in detecting or excluding juxtaposed atrial appendages.

Synthesis and structure of osmium and ruthenium complexes containing tetrafluoroethylene and maleic anhydride as ligands

The d 8 complexes, M(CO)(L)(PPh 3) 3 (M = Ru, Os; L = CO, CNR; R = p-tolyl) and OsCl(NO)(PPh 3) 3, all form simple 1 : 1 π-adducts with tetrafluoroethylene and maleic anhydride, with the overall coordination geometry being dependent upon the relative electron-withdrawing properties of the olefin and the relative electron richness of the metal fragment. In all the tetrafluoroethylene complexes of ruthenium examine, the geometry of the complex involves cis-triphenylphosphine ligands. The X-ray crystal structure of Ru(C 2F 4(CO) 2(PPh 3) 2 is presented as an example of this structural class. Ru(C 2F 4)(CO) 2(PPh 3) 2 crystallises in the monoclinic space group P2 1/ a with a cell having dimensions a = 35.940(2), b = 10.655(7), c = 18.559(6) Å and β = 93.21(3)°, with two crystallography independently molecules in the asymmetric unit ( Z = 8). The osmium complexes do not display this strong preference for cis-triphenylphosphine ligands and Os(C 2F 4)(CO) 2(PPh 3) 2 exists as two separate but interconvertible isomers in solution. One isomer has the same relative geometry as Ru(C 2F 4)(CO) 2(PPh 3) 2. The other has trans-triphenylphosphine ligands. This temperature-dependent equilibrium has been studied by variable-temperature NMR and has Δ H° = −15 kJ mol −1 and Δ S° = −60 J K −1 mol −1. The maleic anhydride complexes also show a variation in geometry from the usual trans triphenylphosphine arrangement. The X-ray crystal structure of Os(maleic anhydride)(CO) 2(PPh 3) 2 is reported along with the solution structures of other maleic anhydride complexes. Os(maleic anhydride)(CO) 2(PPh 3) 2 crystallises in the monoclinic space group P2 1/ c with a cell having dimensions a = 23.667(2), b = 20.306(1), c = 16.147(1) Å and β = 93.20(1)°, with two crytallographically independent molecules in the asymmetric unit ( Z = 8). The triphenylphosphine ligands are again cis but only one lies in the plane of the osmium and the coordinated olefin.

New magnetoelastic force sensor using amorphous alloys

Most amorphous alloys combine good mechanical properties with appropriate magnetic properties. They possess a high permeability as well as a large range of elastic strain with very small elastic hysteresis. Due to their magnetoelastic properties, some amorphous alloys can be used as force-sensing materials.This work deals with sensors for tensile forces using only one single ribbon of an amorphous alloy. In contrast to conventional strain gauges, these ribbons are strong enough to serve as the load-bearing component, which avoids fixing the sensor element to another elastic material.Using the usual arrangement of coaxial coils for transmitting and receiving, the maximum permeability, the remanence, the coercive force and the magnetic losses have been studied as functions of the applied force for three different materials (Fe70 Ni8 Si10 B12, Ni39 Fe39 Mo4 Si6 B12 and Co75 Si15 B10). In addition, a very promising novel sensor principle has been found by providing the individual thin ribbons with a modified arrangement of solenoidal coils. In this case a seeming change of the saturation magnetization is a suitable and sensitive measuring signal.

Surgical implications of juxtaposition of the atrial appendages: A review of forty-nine autopsied hearts

We studied 49 hearts with juxtaposition of the atrial appendages, concentrating on the associated malformations and features of operative importance. Left juxtaposition was found in 42 cases (86%) and right juxtaposition in seven cases (14%). In the group of hearts with right juxtaposition, a normal segmental arrangement was present in three cases, double inlet in two cases, and double-outlet right ventricle in the remaining two cases. Hearts with left juxtaposition had usual atrial arrangement with concordant atrioventricular connection, together with anomalous ventriculoarterial connection in 22 cases and univentricular atrioventricular connection in 19 cases. Only one specimen had a normal segmental arrangement. A partial form of left juxtaposition was present in 60% of the specimens. Hearts with left juxtaposition had a transverse orientation of the atrial septum, which was displaced posteriorly and inferiorly in the medial atrial wall, separated from the orifice of the juxtaposed appendage by a muscular band. A small right atrial chamber was noted in hearts with anomalous ventriculoarterial connection, creating the potential for anatomic difficulties during operation conducted within the atria. In two thirds of the cases with classic tricuspid atresia, the size of the orifice of the juxtaposed appendage was larger than the atrial septal defect, and an anastomosis of the appendage with the pulmonary trunk was morphologically feasible.

An unusual ventricular loop associated with right juxtaposition of the atrial appendages

We report two autopsied cases of an unusual ventricular loop in hearts with right-sided juxtaposition of the atrial appendages. Case 1 showed usual atrial arrangement, a concordant atrioventricular connexion with a disharmonious ventricular loop showing left-hand topology and double outlet right ventricle with normally related arterial trunks. The atrioventricular connexions were crossing, with the inlet to the left-sided morphologically right ventricle being posterior to that of left ventricle. Mitral hypoplasia and coarctation of the aorta were the associated lesions. The second case showed usual atrial arrangement, a discordant atrioventricular connexion with an imperforate left atrioventricular orifice and double outlet right ventricle with the aorta in the right-sided position. A large right atrium was connected to right-sided morphologically left ventricle. A prominent dimple in the left atrial floor was firmly attached to the hypoplastic right ventricle which was left-sided and anterior. A small but discrete inlet portion of the right ventricle could be traced towards the anteriorly located left atrial dimple. Thus, despite the presence of a discordant atrioventricular connexion with the usual atrial arrangement, there was right-hand ventricular topology. In each case the inlet component of the ventricular septum was displaced, being to the right in case 1 and anteriorly in case 2. We suggest that the embryologic mechanism producing disharmony between the atrioventricular connexion and the segmental combinations be interpreted on the basis of posterior ventricular looping, since they are best explained on the basis of a hypothetical heart with posteriorly located outflow tracts.

Cross sectional echocardiographic anatomy of common atrioventricular valve in atrial isomerism.

The morphology of the common atrioventricular valve and its relation to the ventricles was assessed by cross sectional echocardiography in 17 patients with atrial isomerism--four with left isomerism and 13 with right isomerism. In 13 patients the atrioventricular valve consisted of four leaflets: a large anterosuperior leaflet, two lateral leaflets, and a posteroinferior leaflet. The remaining four patients had two anterosuperior leaflets. Five patients had hearts with a double inlet right ventricle and all of them had a rudimentary left ventricle. All the commissures were attached to the right ventricle. Five patients showed severe right ventricular dominance. The atrioventricular morphology in these five hearts differed from that in the patients with the usual atrial arrangement, concordant atrioventricular connection, and hypoplasia of the left ventricle. Only the anterosuperior leaflet bridged the rudimentary left ventricle, and the posteroinferior leaflet was tethered to the ventricular septal crest. Six patients had a biventricular atrioventricular connection and two of them showed mild right ventricular dominance. The atrioventricular morphology in these hearts was the same as that seen in the patients with usual atrial arrangement and a concordant atrioventricular connection. The remaining patient showed dominance of the left ventricle. Only the anterosuperior leaflet bridged the rudimentary right ventricle in this heart.

Nonconventional joint-transform correlator

A nonconventional joint-transform correlator (NJTC) is discussed. We show that the shift-invariant property of the usual joint-transform arrangement can be preserved. The advantages of the NJTC are the efficient use of the light source, the use of smaller transform lenses, higher correlation peaks, and a higher carrier fringe frequency.