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We sought to determine the predisposing factors of pulmonary vascular disease (PVD) in complete atrioventricular septal defect. Down's syndrome is considered a risk factor for PVD, but the progression of PVD differs in each case. Morphometric analysis in autopsied hearts showed that Rastelli type A morphology had a narrower left ventricular outlet and a wider right ventricular outlet than did type C. In 81 consecutive patients with Down's syndrome who underwent cardiac catheterization, we estimated the following variables: Rastelli subtypes, pulmonary vascular resistance, pulmonary-to-systemic flow ratio, patients' age, and operative outcome. The hemodynamic variables in those <1 year old did not differ between the groups with type A and type C. However, all 5 patients with fatal pulmonary hypertension in early infancy had type A morphology. The lung histology revealed that 3 of these patients already had irreversible PVD. At >/=1 year old, those with type A showed a significantly higher pulmonary vascular resistance (p <0.001) and a lower pulmonary to systemic flow ratio (p <0.05) than did those <1 year old. In contrast, neither of these variables in the type C group differed between those >/=1 and <1 year old. Moreover, those with type A had a greater risk of being contraindicated for surgical repair (p <0.05). We suspect, therefore, that type A morphology is an independent risk factor for PVD in those with Down's syndrome associated with this anomaly. This hemodynamic influence could become obvious once patients are >/=1 year old. It may also sometimes result in irreversible PVD even in early infancy.

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To clarify the binding properties of hepatitis C virus (HCV) core protein and its viral RNA for the encapsidation, morphogenesis, and replication of HCV, the specific interaction of HCV core protein with its genomic RNA synthesized in vitro was examined in an in vivo system. The positive-sense RNA from the 5' end to nucleotide (nt) 2327, which covers the 5' untranslated region (5'UTR) and a part of the coding region of HCV structural proteins, interacted with HCV core protein, while no interaction was observed in the same region of negative-sense RNA and in other regions of viral and antiviral sense RNAs. The internal ribosome entry site (IRES) exists around the 5'UTR of HCV; therefore, the interaction of the core protein with this region of HCV RNA suggests that there is some effect on its cap-independent translation. Cells expressing HCV core protein were transfected with reporter RNAs consisting of nt 1 to 709 of HCV RNA (the 5'UTR of HCV and about two-thirds of the core protein coding regions) followed by a firefly luciferase gene (HCV07Luc RNA). The translation of HCV07Luc RNA was suppressed in cells expressing the core protein, whereas no significant suppression was observed in the case of a reporter RNA possessing the IRES of encephalomyocarditis virus followed by a firefly luciferase. This suppression by the core protein occurred in a dose-dependent manner. The expression of the E1 envelope protein of HCV or beta-galactosidase did not suppress the translation of both HCV and EMCV reporter RNAs. We then examined the regions that are important for suppression of translation by the core protein and found that the region from nt 1 to 344 was enough to exert this suppression. These results suggest that the HCV core protein interacts with viral genomic RNA at a specific region to form nucleocapsids and regulates the expression of HCV by interacting with the 5'UTR.

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BACKGROUND: Little attention has been paid to whether the interventricular communication in complete atrioventricular septal defect is different beneath the superior and inferior bridging leaflets, a feature of obvious surgical significance. METHODS: We searched for a defect under the bridging leaflets and examined the valve morphologies in 98 autopsied and 86 surgical patients. Of the overall specimens, 27 were associated with Fallot's tetralogy, and a further 20 had subaortic stenosis, aortic coarctation, or both. In the autopsied specimens, we also measured the degree of deficiency of the ventricular septum. RESULTS: No communication was found under the inferior bridging leaflet in 30% (29 of 98) of the specimens. All 29 hearts except two without such communications showed an undivided inferior leaflet. In contrast, all patients undergoing operation except 1 had a communication beneath both bridging leaflets (p < 0.001). The absence of a communication beneath the inferior leaflet was observed more in hearts with Fallot's tetralogy (seven of 14) or those with subaortic stenosis, aortic coarctation, or both (eight of 18) than in those without associated anomalies (14 of 66; p < 0.01). Those with a communication under the inferior leaflet showed a greater deficiency of the inlet ventricular septum than did those without it (p < 0.001). CONCLUSIONS: In a certain percentage of patients with complete atrioventricular septal defect, there will be no communication under the inferior bridging leaflet. Surgeons should be aware of this possibility, particularly when confronted with a patient with obstruction in either ventricular outlet.

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OBJECTIVES: We sought to determine the intrinsic risk factors of valve regurgitation in complete atrioventricular septal defect. BACKGROUND: Progression of regurgitation varies in each case, although the structure of the common atrioventricular valve itself is a predisposing factor. METHODS: In 90 consecutive patients undergoing surgical repair, we evaluated the preoperative and postoperative regurgitation, valve morphology, age at surgery and associated anomalies. A regurgitation jet with a high velocity reaching the deep left atrial wall by echocardiography was estimated as marked regurgitation. RESULTS: None of the 40 patients with Rastelli type C and an undivided inferior bridging leaflet had preoperative regurgitation in the first year of life, and 12% of them (95% confidence intervals [CI]: 0% to 28%) showed regurgitation at the age of 2. Of the remaining 50 with Rastelli type A and/or a divided inferior leaflet, regurgitation was determined in 21% (95% CI: 6% to 35%) of those 1 year old and in 49% (95% CI: 29%7 to 69%) of those 2 years old (p < 0.01). All patients underwent corrective surgery using the double-patch technique, with the "cleft" being sutured adequately. Irrespective of the valve morphology, regurgitation remained in 52% (12 of 23) of those with preoperative regurgitation, whereas regurgitation developed postoperatively in 28% (16 of 58) of those without regurgitation (p < 0.001). CONCLUSIONS: Those with Rastelli type C and an undivided inferior leaflet had a lesser degree of progression of preoperative regurgitation. However, regurgitation was likely to exist even after adequate repair once regurgitation had already advanced. Therefore, early primary repair before progression of the regurgitation may be the key to maintaining better competence of the atrioventricular valve.

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OBJECTIVES: We sought to analyze morphometric features of atrioventricular septal defect (AVSD) in autopsy specimens and to consider the developmental implications of obstruction in either ventricular outflow tract. BACKGROUND: Left ventricular outlet obstruction (LVO) is more prevalent in patients with Rastelli type A morphology. When tetralogy of Fallot (ToF) complicates this malformation, there is usually a free-floating superior bridging leaflet. The reasons for these associations are uncertain. METHODS: In 133 hearts with AVSD and common atrioventricular (AV) valve orifice, we measured the degrees of horizontal and anterior deviation of the great arteries from the AV valve, the diameters of the ventricular outlets and the great arteries and the degree of deficiency of the ventricular septum. RESULTS: In Rastelli type A morphology, the great arteries were deviated more leftward than in type C morphology (p < 0.01). Type A hearts also had a relatively small aorta, with a long and narrow subaortic tract. The presence of obstruction in either ventricular outlet was associated with a more oblique arrangement of the great arteries, with the pulmonary trunk being more leftward than in hearts without LVO (p < 0.01). In combination with ToF, the aorta was dextroposed and the pulmonary trunk was located more posteriorly (p < 0.01). No heart with type A morphology showed ToF (p < 0.01). CONCLUSIONS: The geometric arrangement of the great arteries correlated significantly with obstruction in either ventricular outflow tract and with the Rastelli subtypes. Malrotation of the developing outlet septum may be an embryologic factor producing obstruction, with horizontal deviation of the outlets also influencing the morphology of the superior bridging leaflet.

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Twins with pulmonary atresia, intact ventricular septum, and hypoplastic right ventricle associated with underdeveloped and discontinuous left pulmonary artery are described. Operations to connect the left pulmonary artery to the main pulmonary trunk, with subsequent biventricular repair assisted by bidirectional cavopulmonary anastomosis and atrial fenestration were performed. Follow-up catheterization proved spontaneous closure of the fenestration in one patient. Both patients have been in a satisfactory condition for 3 years since operation.

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A 13 year old girl with multiple arterial stenoses of unknown aetiology is described. At the age of seven months she was noted to have cardiomegaly and diminished left ventricular ejection fraction with no cardiac anomaly. Cardiac function gradually improved and her condition remained satisfactory until she was 11 years old when multiple lesions in the coronary, cerebral, and left brachial arteries were diagnosed. Histological examination of an endomyocardial biopsy specimen from the right ventricle showed hypertrophic muscles surrounded by abundant fibrous tissue. Percutaneous transluminal angioplasty of the right coronary stenoses led to complete occlusion.

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OBJECTIVE: To clarify the morphological features relating to an intermediate axis or a right axis deviation in atrioventricular septal defect (AVSD). SUBJECTS: 135 patients with typical AVSD and with nine patients with atypical AVSD, characterised by a well formed atrial septum, a milder downward displacement of the atrioventricular valves, and a shorter length of the ostium primum defect. MAIN OUTCOME MEASURES: Relation between morphology and electrocardiographic and vectorcardiographic findings; prevalence of Down's syndrome and of other cardiac anomalies. RESULTS: All nine patients with atypical AVSD had an unusual mean frontal QRS axis compared with six of the 135 patients (4%) with typical AVSD (p < 0.01). All eight patients who underwent the vector analyses showed atypical movement of the QRS loop--that is, an initial left inferior movement in the frontal loop (eight patients) and counter-clockwise rotation in the sagittal loop (seven). The corresponding values for 119 patients with typical AVSD were 20 and 22 patients (p < 0.01). Seven patients with atypical AVSD (78%) and 55 (41%) with typical AVSD had Down's syndrome (p < 0.05). None of the twenty one patients with additional cardiac anomalies had atypical AVSD, an unusual QRS axis, or unusual movement in the QRS loop. CONCLUSIONS: The atypical morphology, supposedly related to the degree of posteroinferior displacement of the conduction system, was one of the causes of unusual movement of the QRS loop in AVSD.

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The case of a 13-year-old girl with multiple coronary stenoses and abundant collaterals, but no risk factors, is described. She was not suspected of having ischemic heart disease until an abnormal electrocardiographic pattern was detected during a routine examination in school. All children with electrocardiographic abnormality should be carefully examined, even though they have neither symptoms nor coronary risk factors.

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Two cases with prolapse of all four cardiac valves are described and compared with two similar ones previously reported. The severity and progression of regurgitation of each of the valves differed by case, despite having similar echocardiographic findings consistent with the diagnosis of multiple floppy valves. Two of the four patients had their aortic valve replaced because of severe regurgitation: the excised valves revealed myxomatous degeneration. None of the patients had any stigmata of Marfan or Ehlers-Danlos syndrome, except for the presence of hyperextensive joints. There may be an unknown collagen disorder that caused floppiness in all the valves.

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We experienced four boys (two siblings) whose cardiac valves were all prolapsed, which have never been reported as a recognized disease. All had hyperextensive joints without any other stigmata of Marfan or Ehlers-Danlos syndrome. The severity and progression of regurgitation of each valve differed by a case, though they had similar echocardiographic findings consistent with the diagnosis of multiple floppy valves. Three of the four patients had severe aortic regurgitation, and two received aortic valve replacement. Their excised valves revealed myxomatous degeneration. The tricuspid valves were more thickened and redundant than the mitral valves. Although three patients had moderate tricuspid regurgitation, none of them had clinically important mitral regurgitation. We recommend aortic and/or mitral valve replacement, whenever the regurgitation exacerbates left ventricular dilatation. Aortic regurgitation deteriorated rapidly in one case due to valve rupture. In this case, moderate tricuspid regurgitation was relieved after aortic valve replacement. Skin fibroblast did not show any abnormalities in collagen biosynthesis.

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We report on a case of hypoplastic left heart syndrome (HLHS), associated with premature closure of the foramen ovale and an unusual type of totally anomalous pulmonary venous return. The existence of an anomalous connection of the right upper pulmonary vein to the superior vena cava-right atrial (SVC-RA) junction and the existence of the anomalous intrapulmonary venous channel between right upper and lower pulmonary vein allowed all the pulmonary blood to drain into the SVC-RA junction, whereas she had only partially anomalous pulmonary venous connection. The several intrapulmonary venous channels helped to delay the progression of pulmonary venous obstruction. Chromosomal analysis revealed that the patient had XO Turner syndrome. We conclude that all infants with HLHS should be carefully evaluated for the existence of anomalous pulmonary venous return. Two-dimensional Doppler echocardiography is one of the most useful techniques for evaluating such anomalies.

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Two female patients with Ebstein's anomaly, aged 12 and 45 years, underwent new procedures of tricuspid valve replacement in the true annulus without involvement of atrioventricular conduction disturbance. The first patient had a relatively small atrialized right ventricle. A Dacron patch was sutured on the atrialized portion from the right ventricular side. Buttress stitches were placed on the whole of the atrialized ventricle except at the part of the His' bundle. A porcine valve was sutured in the true annulus of the tricuspid valve and on the top of the patch. The second patient had a fairly large atrialized ventricle, and plication was made only in the inferior part of the atrialized ventricle form the coronary sinus. A porcine valve was sutured in the true tricuspid annulus except at the part of Koch's triangle, where the porcine valve was placed on the false annulus.

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