bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathophysiological mechanisms of sudden infant death syndrome
Authors: Stramba-Badiale Marco , Grancini Fabio , Porta Norberto , Schwartz Peter J 
Published: August 2008

AbstractThere is a consensus that sudden infant death syndrome, the leading cause of mortality in the first year of life, is multifactorial. Most of the cases are probably due to respiratory or cardiac disorders. It has been proposed that some cases of sudden infant death might result from ventricular fibrillation triggered by a sudden increase in sympathetic activity affecting the heart with reduced electrical stability. This impairment can be due to an insufficient or delayed development of cardiac vagal innervation, with the resultant lack of its protective effect that has been demonstrated to be present since the third week of life. Clinical studies suggest that some of the sudden infant death victims may have a reduced heart rate variability that could be interpreted as a decreased parasympathetic activity to the heart. On the other hand, a reduced cardiac electrical stability may be provoked by a developmental imbalance in sympathetic innervation such to create a dominance of left-sided nerves. We have demonstrated that an imbalance of this type experimentally induced in puppies increases the susceptibility to ventricular fibrillation and prolongs QT interval. In order to demonstrate a significant relationship between prolonged QT interval and sudden infant death, we performed a large prospective study on 18,832 neonates. QT interval corrected for heart rate (QTc) measured from an electrocardiogram on the fourth day of life, was within the normal limits in nine victims from known causes, while it was exceeding the mean by two standard deviations (>433 msec) in six of 12 sudden infant death victims. If these data are confirmed by a larger multicenter study started in Italy, it will be possible to identify some of the sudden infant death victims by the observation of a prolonged QT interval on the electrocardiogram. In this case a preventive strategy based on a time-limited administration of beta adrenergic blocking agents to the infants at risk, might reduce the incidence of sudden infant death.
Ventilation with external high frequency oscillation around a negative baseline increases pulmonary blood flow after the Fontan operation
Authors: Penny Daniel J. , Hayek Zamir , Rawle Peter , Rigby Michael L. , Redington Andrew N. 
Published: August 2008

AbstractIn this prospective study, pulmonary blood flow was measured using transesophageal Doppler echocardiography to assess whether ventilation by means of external high frequency oscillation around a negative pressure baseline can increase pulmonary blood flow, compared to intermittent positive pressure ventilation, in five patients after the Fontan operation. Pulmonary blood flow was measured when patients were ventilated by means of intermittent positive pressure ventilation and again during equivalent negative pressure ventilation using the external oscillatory technique. When compared to that with intermittent positive pressure ventilation, ventilation using external high frequency oscillation increased pulmonary blood flow by 116 ±61.5% (p=0.013). These results show that ventilation using an external oscillatory device with a mean negative chamber pressure may provide hemodynamic advantages in patients requiring assisted ventilation after the Fontan operation.
Long-term results of aortoventriculoplasty
Authors: Mitchell Ian M , Gnanapragasam James P. , Pollock James C.S. , Houston Alan B. 
Published: August 2008

AbstractObstruction of the left ventricular outflow tract continues to represent a challenging surgical problem, particularly in children. Failure to relieve the obstruction by either valvotomy or myectomy requires enlargement of the ventriculoaortic junction and outflow tract. Alternatively, the obstruction can be by passed using an apical valved veritriculo aortic conduit, althoughthis is associatedwith a high rate oflong-term complications. The use of a small xenograft in children is less than ideal because of early calcification, and the insertion of a mechanical valve may be feasible only after considerable enlargement of the ventriculoaortic junction. Aortoventriculoplasty is particularly suited for this purpose, and it is usually associated with good early results. Yet, long-term experience with this procedure, as far as we know, has not been reported previously. We describe our experience with the use of aortoventriculoplasty in four patients, three of whom have been followed-up for more than five years. Two patients have required reoperation for replacement of their prosthetic valves, one for bacterial endocarditis and the other for fracture of a continuous prolene suture which secured the prosthetic valve to the Dacron septal patch. All patients are currently in good health with continuing satisfactory relief of obstruction to their left ventricular outflow tract.
Novice experience with transcatheter closure of the arterial duct in children, adolescents and adults
Authors: Galal Omar , Wilson Neil , Fadley Fadel Al , Duran Carlos 
Published: August 2008

AbstractNon-surgical occlusion of the arterial duct (ductus arteriosus) has been shown to be effective. Its limitations are yet to be fully defined. We have attempted to elucidate this issue in the setting of our early experience with the procedure, utilizing the Rashkind double disc occluder. After clinical and echocardiographic evaluation, 56 consecutive patients were studied invasively. In two patients, the patent duct was considered too large for occlusion and in one patient it could not be crossed with the diagnostic catheter. In the remaining 53 patients (95%), an attempt to implant the double disc occluder was made. The mean age of all patients was 7.9 years (range 0.16 year to 29 years). There were 35 females (63%) and 21 males. The mean weight was 24.2 kg (range 6.7 kg–85 kg). In five patients (9.5%), the procedure failed. This was due to pull through of the 17 mm device in three patients. In another patient, because of a very small duct (post surgical ligation), it was not possible to deliver the distal legs of the 12mm device. In the last patient, the device embolized to the left pulmonary artery and was retrieved to the groin. Subsequent replacement was not attempted. In 48/53 patients (90.5%) the device was successfully implanted. Nine cases of the 48 in whom the device was implanted (18.8%) showed complete occlusion at 10 minutes and 22 more (45.8%) five to 24 hours after the procedure. A total of3 1/48 patients (64.5%) were discharged home the day following the procedure with no residual shunt, as judged by color flow Doppler studies. The mean duration of the procedure in all patients was 94 minutes (range 47 to 244). The fluoroscopy time ranged from 3 to 81 minutes with a mean of 17 minutes. Follow-up data (between five days and 18 months) are available in 20/48 patients. Three patients had a clinically detectable residual shunt, with an audible continuous murmur six months after the procedure. All three have undergone complete occlusion using a second device. One more patient showed spontaneous occlusion on follow-up. So far, a total of 35/48 patients (72.9%) have had complete occlusion of the patent duct. We conclude that not all patients with an arterial duct are amenable to occlusion using the Rashkind device. The procedure appears to be safe when performed by a suitably trained novice, nonetheless, and successful implantation can be achieved in over 90% of patients.
Valvar regurgitation in normal children: Is it clinically significant?
Authors: da Silva Mattos Sandra , Severi Rossana , Cavalcanti Catarina Vasconcelos , da Fonte Freire Monica , Filho Djair Brindeiro 
Published: August 2008

SummaryThis study aimed to assess the prevalence of “silent” valvar regurgitation in healthy Brazilian children; to determine whether variations in the gain settings of the machine interfered with its documentation; and to compare Doppler color flow mapping with the pulsed wave Doppler. Twenty-five healthy children were selected randomly. Echocardiographic equipment used was ALOKA 870. Fixed parameters were 3.5 MHz transducer, 400 Hz filter, reject of 7/14 and aperture of 30/80. Variable parameters were Doppler color flow mapping and pulsed wave Doppler gains. A protocol for evaluation of each cardiac valve was developed. Regurgitation was noted in 93% for the pulmonary valve, 74% for the tricuspid valve and 27% for the mitral valve. In the aortic valve, jets suggestive of mild valvar regurgitation were observed with the Doppler color flow mapping technique in two children but these findings were not corroborated by pulsed wave Doppler. Only in the aortic valve were findings from Doppler color flow mapping not in agreement with those from pulsed wave Doppler. Variations in the settings for gain did not interfere significantly in the documentation of regurgitation. Inter-observer variations were not significant (two independent operators). The clinical implications of these findings are yet to be established. Labeling these regurgitant jets as “normal” may be oversimplifying their meaning and perhaps overlooking the possibility of predisposition to endocarditis or progression of the valvar abnormality. Conversely, labeling them as “abnormal” can generate a more serious problem, which is that of iatrogenic heart disease. Prospective follow-up studies should be carried out in these subjects.
Prenatal diagnosis of isomerism of the right atrial appendages
Authors: Rossi Giuseppe , Corno Antonio , Montemurro Giuseppe 
Published: August 2008

AbstractA complex malformation of the heart was diagnosed by fetal echocardiography at 27 weeks of gestation. The study of the relationship of the abdominal great vessels, showing the inferior caval vein anterior and to the left of the aorta, made possible the diagnosis of right isomerism. This inferential guide to the arrangement of the thoraco abdominal organs proves to be as valid in the fetus as it is in the neonate and child. The examination of the abdominal great vessels as part of the fetal scan is of great value, enabling us to counsel mothers appropriately in the light of the poor prognosis of neonates with isomerism of atrial appendages and complex intracardiac lesions.
The potentially obstructive subaortic region and banding of the pulmonary trunk—selected observations in the patient considered for a Fontan procedure
Authors: Freedom Robert M. , Akagi Teiji , Benson Leland N. 
Published: August 2008

SummaryThere is a clear and present danger for the patient considered for Fontan's operation in the presence of excessive ventricular hypertrophy and/or mass. Such ventricular hypertrophy and/or mass probably reflects singly, or in combination, banding of the pulmonary trunk and subaortic stenosis, as well as other factors. While one can construct a number of therapeutic algorithms for patients seen at various ages with a restrictive ventricular septal defect and subaortic stenosis in the setting of double inlet left ventricle and discordant ventriculoarterial connections, the optimal management should be to minimize the potential risks for development of subaortic stenosis and excessive ventricular hypertrophy and/or mass.
Morphologic and hemodynamic results of staged repair of pulmonary atresia with ventricular septal defect in the presence of hypoplastic pulmonary arteries and systemic-to-pulmonary collateral arteries
Authors: Wilkinson James L. , Ng Yin Ming , Iyer Krishnan S. , Mee Roger B. B. 
Published: August 2008

AbstractFollow-up cardiac catheterization and angiography was performed in 23 patients after complete, staged repair of pulmonary atresia with ventricular septal defect and multiple systemic-to-pulmonary collateral arteries. Time interval from repair varied from 0.2 to 89 months (mean 26 months). Major residual anomalies of arborization of the pulmonary arteries, with or without pulmonary vascular disease, were present in six patients, two of whom had die patch on the ventricular septal defect perforated because of systemic or suprasystemic right ventricular pressure in the early postoperative period after repair. Both of these children later died, while the other four patients were found to have moderately to severely elevated ventricular pressure ratios and pulmonary arterial pressure measurements, though they are all alive at follow-up intervals from 20 months to 6.8 years. The remaining 17 patients all had hemodynamically satisfactory or good results, with pulmonary arterial mean pressures ranging from 8 to 30 mm Hg (mean 22 mm Hg) and pressure ratios between the ventricles from 0.24 to 0.75 (mean 0.43)—the higher ratios generally reflecting gradients across the conduit valve. Angiography demonstrated that the hypoplastic pulmonary arteries increased in size to normal dimensions, during staging, in most patients, though abnormalities of arborization persisted in several. Analysis of the data from the entire cohort of 58 patients, who were accepted for staging towards repair, showed a significant association between early age at entry to the program and likelihood of complete repair being achievable.
Pulmonary vascular disease in children with congenital heart defects living at high altitude—a quantitative morphometric lung biopsy study
Authors: Balaji Seshadri , Hislop Alison A. , Levin Solomon E. , Haworth Sheila G. 
Published: August 2008

SummaryLung biopsies were taken from 30 children aged three months to 15 years (median, 11 months) who had pulmonary hypertensive congenital heart disease and were living at an altitude of 1750 meters. They had either a ventricular septal defect and/or patency of the arterial duct, atrioventricular septal defect or complete transposition with a ventricular septal defect. Biopsies were studied using quantitative morphometric light microscopic techniques. All patients with a ventricular septal defect with or without patency of the arterial duct showed a significant increase in mean percentage arterial medial thickness of both pre- and intraacinar pulmonary arteries compared with those of normal children of similar age living at sea level (p<0.001 for both pre- and intraacinar vessels) and with children with a ventricular septal defect living at sea level (p<0.001 for both pre- and intraacinar vessels). Extension of muscle to more peripheral pulmonary arteries was also greater. Intimal proliferation and fibrosis was seen in 10 patients, in three of whom it was severe. Intimal proliferation occurred more frequently than in children with a ventricular septal defect living at sea level. The findings were similar in patients with atrioventricular septal defect and complete transposition with ventricular septal defect. These findings suggest that patients with congenital heart disease who live at a relatively high altitude develop pulmonary vascular disease more rapidly than do those living at sea level.
Variability of the diameter of the pulmonary outflow tract and its relation to balloon valvoplasty for congenital pulmonary valvar stenosis
Authors: Lo Roxy N. S. , Leung Maurice P. , Yung T. C. , Chan C. H. 
Published: August 2008

SummaryThe diameter of the pulmonary outflow tract was measured from the right ventricular cineangiogram at different phases of the cardiac cycle prior to balloon valvoplasty in 54 patients with congenital pulmonary valvar stenosis. Measured at the level of the hinge point of the valvar leaflets, the pulmonary outflow tract was found to be largest at end-diastole and smallest at end-systole. The mean increase in diameter from systole to diastole was 25.3% (range 6–53%) for 47 patients with typical valvar stenosis, and 24.3% (range 14–41%) for seven patients with dysplastic valvar leaflets (p>0.5). Dilatation using balloons less than 1.2 times the size of the maximal end-diastolic diameter produced a mean reduction in the pressure gradient from right ventricle to pulmonary trunk of 71.1%, compared to 76.2% with bigger balloons (p>0.3). Two patients with an initial ratio between balloon and outflow tract of 0.9 required a second dilatation. The timing of measurement of the diameter of the pulmonary outflow tract should be standardized. Oversized balloons probably are not necessary for pulmonary valvoplasty.
Sectional anatomy of the ventricular septal defect in double outlet right ventricle—correlation of magnetic resonance images from autopsied hearts with anatomic sections
Authors: Yoo Shi-Joon , Ho Siew Yen , Kilner Philip J. , Seo Jeong-Wook , Anderson Robert H. 
Published: August 2008

AbstractA ventricular septal defect is, almost always, an integral part of double outlet right ventricle and has been classified into the subaortic, subpulmonary, doubly committed and non-committed varieties. This study was performed to correlate the cross-sectional imaging characteristics of such ventricular septal defect in double outlet right ventricles using pathological specimens. The extent and the orientation of the outlet septum were the most important in the differentiation of the four varieties of ventricular septal defect. In the subaortic variety, the outlet septum fused with the left anterior margin of the defect, this being marked by the anterior limb of the septomarginal trabeculation. In the subpulmonary variety, the outlet septum fused with the right posterior margin of the defect, this being the posterior limb of the septomarginal trabeculation. The outlet septum was vestigial in case with doubly committed defects. In those with non-committed defects, the defect was not shown in those images or sections which demonstrated the outlet septum.
Double outlet right ventricle—an echocardiographic study
Authors: Martínez Oscar Arista-Salado , Casado José Arango , de la Cruz María V. , Díaz Francisco , Cubero Osiris 
Published: August 2008

SummaryWe examined the echocardiograms of 40 patients with double oudet right ventricle, proven either at autopsy or during surgery. By way of the subcostal approach, it proved possible to determine the insertion of the outlet (infundibular) septum and to categorize the malformations within the classification proposed by de la Cruz and her colleagues. It was also possible to ascertain the relationships of the atrioventricular valves with one or with both infundibulums, and these features could be correlated with infundibular interrelationships. The interrelationship of the great arteries, in contrast, was not always in accordance with the infundibular interrelationships, indicating that the arterial interrelationship may not prove to be a good parameter for surgical decision-making. Of greatest importance was the visualization and echocardiographic appraisal of the spatial position and size of the ventriculoinfundibular fold, since this anatomic feature was the key to determining the optimal surgical approach. This is so because the ventriculoinfundibular fold constitutes one of the borders of the ventricular septal defect, and separates it from the plane of the leaflets of the arterial valves. Furthermore, the fold frequendy contributes to infundibular obstruction. Our echocardiographic studies, based on a better anatomic knowledge, permitted us to choose the most suitable surgical technique in our patients.
Evidence for a quantitative genetic influence on the formation of aortic valves with two leaflets in the Syrian hamster
Authors: Sans-Coma Valentín , Cardo Manuel , Durán Ana C. , Franco Diego , Fernández Borja , Arqué José M. 
Published: August 2008

SummaryWe studied the morphology of the aortic valves of 1,036 Syrian hamsters belonging to two families subjected to high endogamous pressure. Most (n=955) specimens were examined using a corrosion-cast technique. In the remaining 81 specimens, valvar morphology was assessed by means of a stereomicroscope, and in 18 of these cases a histologic study was also performed. In one of the families, a high proportion (30.5%) of hamsters had aortic valves with two leaflets, the aortic sinuses being oriented ventrodorsally. The percentage of such anomalous valves was found to be positively correlated with the inbreeding coefficient of specimens. In the other family, the occurrence of an aortic valve with two leaflets was a sporadic event. Stereoscopic and histologic observations demonstrated that, in 52 of 63 aortic valves with three leaflets, the ventral commissure between the right and left leaflets was partially fused, while in 10 other cases this commissure was completely fused. In addition, in nine of 18 aortic valves with two leaflets, there was a more or less well-developed raphe located in the ventral aortic sinus, approximately where the true ventral commissure would have been. Our observations suggest the existence of a continuous spectrum of aortic valvar morphology, ranging from a valve with three leaflets and no fusion of the ventral commissure to an aortic valve with two leaflets devoid of any raphe. This spectrum seems to be the result of the interaction of genetic and intrauterine environmental factors. Results of crosses between both related and unrelated hamsters suggest that the observed morphology in individuals is the result of quantitative inheritance.
Outcome of isolated fetal pericardial effusion
Authors: Wyllie Jonathan P. , Hunter Stewart 
Published: August 2008

SummaryIsolated fetal pericardial effusion is generally held to have a good prognosis. We report a study of seven cases identified from a total of 504 fetuses scanned and followed with serial fetal scans.Our results show that it was associated with a poor fetal prognosis in six of the seven pregnancies. Probably due to the high incidence of mid-trimester abortion and the association with other abnormalities only evident postnatally, this has not, hitherto, been reported. We would advocate close follow-up and a guarded prognosis when isolated pericardial effusions are found on fetal scans.
The postoperative pathology of congenital heart disease
Authors: Anderson Robert H. , Ho Siew Yen 
Published: August 2008

AbstractThe role of the pathologist is changing with regard to the assessment of postoperative congenital heart disease. Whereas, in the past, the access to autopsied hearts provided the opportunity for detailed description and classification, nosologic details of cardiac malformations are now largely agreed. While a detailed analysis of the lesion remains an integral part of the pathologist's task, future advances will now largely be dictated by careful analysis of the effects of cardiac surgery. Such analysis can be divided into early and late phases. When assessing the specimen from a death occurring in the operating room or in the immediate postoperative period, the pathologist must examine carefully the operative incisions, and the correctness of the surgical procedure. Proper assessment of the procedure will necessitate removal of patches and pathways constructed by the surgeon, having documented carefully the location of sutures used to secure the foreign materials. The autopsy must also include assessment of the organs in the rest of the body, particularly the lungs, and must not ignore the immediate effect of the operative procedure on myocardial status. In the late phase, while again assessing in detail the access to the heart and the procedures employed during surgical correction, the pathologist will take care to evaluate the long-term effects of the procedure on the valves of the heart, the myocardium, the pulmonary vasculature and the other organs. At this stage, care should also be taken to ensure that late scarring does not involve the conduction tissues. Particular care will be needed when assessing the efficacy and durability of prosthetic materials inserted into the heart. Most of these steps will be undertaken intuitively by the pathologist, but interest in cardiac pathology as a specialty seems to be waning. The clinician can combat this trend by ensuring that all cases dying after operative procedures are obtained for autopsy, and by encouraging the pathologist to become involved in this fascinating area.