Search PubMed⌕ Search

Biomedical subjects

W H Neches

Publications and source records attributed to W H Neches.

At least 37 records · Page 2Linked to original sources
PubMed1987

Experience with heart transplantation in children.

Between March 1981 and March 1986, 200 orthotopic heart transplantations were performed at the University of Pittsburgh. Fourteen of those procedures were carried out in children 2 to 16 years of age. Two children received combined liver and heart transplants; one because of familial hypercholesterolemia with associated ischemic heart disease, and the other because of dilated cardiomyopathy associated with intrahepatic biliary atresia. Eight patients had dilated cardiomyopathy, and two had myocarditis. Two had heart transplantations for congenital heart disease: one had multiple muscular ventricular septal defects repaired in infancy and had an associated cardiomyopathy, and the other developed a cardiomyopathic ventricle from a congenital right coronary artery to right atrial fistula. Chronic immune suppression consisted 0.2 to 0.5 mg/kg/d of prednisone and 5 to 50 mg/kg/d cyclosporine, with the addition of antithymocyte globulin for unresolved moderate or severe acute rejection. There were three early postoperative deaths: one from intracranial bleeding, one from Pseudomonas mediastinitis, and one from ischemic injury to transplanted organs. Early postoperative complications included reversible renal failure, hypertension, and seizures. Late problems were related to allograft rejection and side effects of cyclosporine and corticosteroids. Significant rejection episodes occurred in all patients surviving longer than 2 weeks, with seven requiring antithymocyte globulin. Two patients died 8 months following transplantation of severe acute and chronic rejection; another patient required retransplantation for ischemic cardiomyopathy resulting from chronic rejection but subsequently died of recurring rejection 3 months after the second transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Echocardiographic findings before and after liver transplantation.

Echocardiographic studies were performed in 73 patients with various types of chronic liver disease. They were 0.5 to 19 years old (mean 5). Thirteen patients underwent follow-up echocardiography 1 to 13 months (mean 6) after liver transplantation. Preoperatively 60 patients (82%) showed evidence of high cardiac output (cardiac index greater than 4 liters/min/m2); these patients manifested increased left ventricular (LV) and left atrial dimensions and a thickened LV posterior wall. Transvenous contrast echocardiographic study confirmed the presence of intrapulmonary arteriovenous shunting in 4 patients. Studies after liver transplantation revealed a reduced LV end-diastolic dimension in 12 patients. Cardiac index was reduced a mean of 35% after transplantation (p less than 0.001). This study suggests that liver transplantation improves common hemodynamic abnormalities in chronic liver disease.

Adolescent↗
PubMed1985

A percutaneously adjustable device for banding of the pulmonary trunk.

An optimal result is often difficult to obtain with conventional banding of the pulmonary trunk. Furthermore, this procedure has a significant surgical morbidity and mortality. An inflatable device has therefore been developed which consists of an inflatable band and a valve. The band is made of a silicone balloon which is covered with reinforced braid. The band is applied loosely around the pulmonary trunk through a left lateral thoracotomy. The valve is implanted subcutaneously in an intercostal space. The size of the band can be adjusted postoperatively using a needle and fluid-filled syringe percutaneously to inflate or deflate the balloon. Experiments were conducted in 5 animals and follow-up evaluation by cardiac catheterization and angiocardiography was made up to 4 months after implantation of the device. The band could be effectively and reliably adjusted and no malfunction or complication occurred. This preliminary study suggests that this new technique may make banding of the pulmonary trunk a more reliable and effective procedure and may reduce surgical morbidity and mortality. It also may avoid or delay subsequent additional surgery for revision of a band which is too tight or too loose.

Animals↗
PubMed1985

Ventricular septal defect associated with aneurysm of the membranous septum.

The most common variety of ventricular septal defect, a perimembranous defect, is frequently associated with a so-called aneurysm of the membranous septum. Previous studies have suggested that ventricular septal defects associated with an aneurysm of the membranous septum tend to spontaneously decrease in size or close more than defects without such an aneurysm. To better define the natural history of this entity, clinical and catheterization data from 87 patients with ventricular septal defect and aneurysm of the membranous septum were reviewed. The initial evaluation was made at a median age of 0.3 years (range 0.1 to 11), with the final evaluation at a median age of 10 years (range 1.5 to 20) and a median duration of follow-up of 8.6 years (range 1.2 to 18.8). Approximately 75% of the ventricular septal defects had a small or no left to right shunt at last evaluation. Overall, 48 patients (55%) had no significant change in the size of the defect, and 39 (45%) showed improvement during the period of observation. Only four patients (5%) had spontaneous closure of the defect. Of the 49 patients who presented with a large left to right shunt, with or without congestive heart failure, 23 (47%) had persistence of a shunt large enough to warrant surgery. When spontaneous improvement occurred, it did so by 6 years of age in all but one patient. Therefore, a continued tendency for a ventricular septal defect associated with an aneurysm of the membranous septum to spontaneously decrease in size or close after this age may be less likely than previously suggested.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm↗
PubMed1985

Atrial flutter in the young: a collaborative study of 380 cases.

As children with cardiac disease grow older, atrial flutter becomes more prevalent. A collaborative study was performed in 19 institutions to determine the clinical characteristics of these children and the factors affecting prognosis. There were 380 patients with one or more electrocardiographically documented episodes of atrial flutter that first occurred between ages 1 and 25 years (mean age at onset 10.3). Episodes of flutter continued to occur for a mean of 2.5 years after the onset. Of the 380 patients, 60% had repaired congenital heart disease, 13% palliated congenital heart disease, 8% unoperated congenital heart disease, 8% an otherwise normal heart, 6% cardiomyopathy, 4% rheumatic heart disease and 2% other lesions. Overall, drugs were effective in eliminating atrial flutter in 58% of patients; specifically, amiodarone and digoxin plus quinidine were effective in 53%, digoxin alone in 44% and propranolol in 21%. Amiodarone was effective in seven (78%) of nine patients. Corrective surgery was performed after the onset of atrial flutter in 66 patients; in 52% the atrial flutter was easier to control or it resolved and in only 4% it was worse. At follow-up (mean 6.5 years), 83% of the patients were alive (49% without atrial flutter and 34% with atrial flutter) and 17% died (10% suddenly, 6% of nonsudden cardiac cause and 1% of noncardiac cause). Cardiac death occurred in 20% of those for whom an effective drug could not be found to eliminate atrial flutter compared with 5% of those who were treated with an effective drug (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Flutter↗
PubMed1985

Of clefts, commissures, and things.

A full understanding of the morphology of atrioventricular septal defects ("endocardial cushion defects," "atrioventricular canal malformations") demands knowledge of the exact nature of three specific breaches in the skirt of valve leaflet tissue guarding the atrioventricular junction. One of these is the space between the left ventricular components of the two leaflets that are enclosed in both the right and left ventricles (the bridging leaflets). Traditionally described as a cleft, it has been suggested more recently that this gap functions as a commissure. The second space is that which is found anteriorly and superiorly in the so-called Rastelli type A malformation. This is also called a cleft in a common anterior leaflet, but it has been suggested that it too is a commissure. The final breach is that produced by the surgeon when he divides the free-floating superior bridging leaflet if repairing the so-called Rastelli type C malformation with a one-patch technique. It is generally agreed that this breach be considered a division. To adjudicate the nature of the other breaches, it is necessary to compare them with commissures in atrioventricular and arterial valves and with the isolated cleft that exists in the aortic leaflet of a normal mitral valve. These considerations show that the gap between the left ventricular components of the bridging leaflets functions as a commissure even though it is not supported by a papillary muscle. This would not be expected, since the commissural attachments of the leaflets are in the left and right ventricle, respectively. The gap seen anteriorly in the Rastelli type A malformation is also a commissure, being supported in typical fashion by the medial papillary muscle of the right ventricle.

Heart Septal Defects↗
PubMed1985

Further observations on the morphology of atrioventricular septal defects.

Certain morphologic aspects of atrioventricular septal defects ("endocardial cushion defects," "atrioventricular canal malformations") remain controversial. It is still not clear which precise lesions should not be placed in this category. For example, is an "isolated" cleft of the mitral valve or a perimembranous inlet ventricular septal defect to be so described? It is also not fully accepted that the left atrioventricular valve in these lesions bears little resemblance to a morphologically mitral valve. We have investigated these problems by both observation and mensuration. We determined the junctional circumference of the left atrioventricular valve leaflets and the ventricular dimensions in 130 atrioventricular septal defects (95 with common valve orifice and 35 with separate right and left atrioventricular orifices); in 50 hearts with perimembranous ventricular septal defects (20 extending into the inlet septum and 30 with outlet or trabecular extensions); in seven hearts with isolated cleft of the mitral valve, and in 10 normal hearts. All specimens came from the cardiopathological collection of Children's Hospital of Pittsburgh. The measurements showed conclusively that the atrioventricular septal defects were all directly comparable irrespective of the detailed morphology of the atrioventricular valve or valves. The group of atrioventricular septal defects was totally discrete as compared with all the other specimens that had normal atrioventricular septation. The left atrioventricular valve in atrioventricular septal defects is basically a three-leaflet valve which differs from the normal mitral valve in terms of its leaflet, its chordal support, and the arrangement of its papillary muscle. Its only similarity with the normal mitral valve is that it resides in the morphologically left ventricle and guards the left atrioventricular junction.

Child↗
PubMed1984

Tetralogy of Fallot with absent pulmonic valve: analysis of 17 patients.

Seventeen patients with tetralogy of Fallot (TF) and absent pulmonic valve were seen at Children's Hospital of Pittsburgh from 1958 to 1981. In 7 patients, severe respiratory symptoms developed due to bronchial compression by an aneurysmal pulmonary artery, and 6 died. In 4 patients, moderate respiratory symptoms developed. Six patients remained free of respiratory distress. Medical and surgical management of patients with respiratory distress in infancy has been frustrating and frequently unsuccessful. A 4-month-old infant with respiratory distress underwent complete intracardiac repair with valve insertion and has subsequently survived with relief of symptoms. Considering the high mortality rate in this group of patients, further attempts at aggressive surgical repair in infancy for patients with severe respiratory symptoms is warranted. An anatomic review of pathologic specimens with this anomaly confirmed previous reports of the frequent association of absence of the ductus arteriosus in patients with tetralogy of Fallot and absent pulmonary valve. The exception is noted in patients with discontinuity between the right and left pulmonary arteries in which a ductus arteriosus may be present supplying the isolated left pulmonary artery.

Abnormalities, Multiple↗
PubMed1984

Surgical management of univentricular heart with subaortic obstruction.

In children with a univentricular heart and a rudimentary subaortic chamber, surgical relief of subaortic obstruction caused by a restrictive bulboventricular foramen is associated with high morbidity and mortality. A 6-year-old child with a univentricular heart of the left ventricular type, a rudimentary subaortic chamber, and atresia of the left-sided atrioventricular valve had pulmonary artery banding in infancy. Severe subaortic obstruction subsequently developed. At operation, the pulmonary artery was transected and the stump was anastomosed directly to the posterior aspect of the ascending aorta, diverting left ventricular blood into the aorta through the pulmonary valve. The distal pulmonary artery was anastomosed side-to-side to the ascending aorta to provide pulmonary blood flow. Cardiac catheterization fifteen months after the operation demonstrated an excellent hemodynamic result. When the pulmonary artery is adequate in size, a bypass operation by way of an anastomosis between the ascending aorta and the pulmonary artery is a relatively safe and effective means of relieving the ventricular outflow obstruction caused by a restrictive bulboventricular foramen.

Aortic Valve Stenosis↗
PubMed1984

Ventricular inversion with normal ventriculoarterial connection and left atrial isomerism: correction by the Mustard operation.

A 2 year old boy with ventricular inversion and normal ventriculoarterial connection is described. Associated cardiac lesions included single atrium, absence of the coronary sinus, bilateral superior venae cavae, absence of the hepatic segment of the inferior vena cava with azygos and hemiazygos continuation, right aortic arch, levocardia and left atrial isomerism. At 5 days of age, the patient underwent a Waterston (aortopulmonary) anastomosis because of suspected pulmonary atresia. The correct diagnosis was established at 2 years of age and the patient had a successful Mustard operation (interatrial baffle procedure) and closure of the Waterston anastomosis. Accurate preoperative diagnosis is difficult in this rare cardiac anomaly and the reported mortality rate is high.

Cardiac Catheterization↗
PubMed1983

Hemodynamic function after the Mustard operation for transposition of the great arteries.

Pre- and postoperative cardiac catheterization data and cinenangiocardiograms of 82 patients who survived the Mustard operation for transposition of the great arteries (TGA) were reviewed. The post-operative catheterizations were performed 20 days to 10 years after operation (mean 2.5 years). Forty-six patients (56%) had no or insignificant associated cardiac lesions, whereas 36 (44%) had ventricular septal defect, pulmonary stenosis, or both, and required surgical intervention at the time of the Mustard operation. Postoperatively, 11 patients (13%) had significant systemic venous obstruction. Of the 11 patients, 6 required reoperation, and 2 patients had evidence of restenosis or complete obstruction in the superior vena cava after reoperation. In most patients, superior vena caval obstruction was well tolerated even in the presence of high pressure in the superior vena cava. Pulmonary venous obstruction occurred in 5 patients (6%), 3 of whom had no clinical symptoms despite severe pulmonary venous obstruction, although all had radiographic evidence of pulmonary venous congestion. The incidence of obstruction was drastically reduced after the Mustard operation was modified to include routine enlargement of the pulmonary venous atrium. Tricuspid regurgitation was uncommon (10%), but did occur in patients who had transatrial closure of a ventricular septal defect. Preoperatively, left ventricular outflow obstruction occurred in 38%. In 12 patients an attempt was made to relieve the obstruction at surgery. The 6 patients who had localized obstruction had a good result, but patients with more diffuse narrowing of left ventricular outflow had little or no relief of obstruction. Mild to moderate left ventricular outflow gradients regressed spontaneously in most patients after the Mustard operation.

Adolescent↗
PubMed1983

Rest and exercise right and left ventricular function late after the Mustard operation: assessment by radionuclide ventriculography.

To evaluate ventricular function late after atrial repair of transposition of the great arteries (TGA), 26 asymptomatic patients had rest and exercise radionuclide ventriculography performed a mean of 9 years (range 5 to 15) after undergoing the Mustard operation. The mean resting right (systemic) ventricular (RV) ejection fraction (EF) was 0.50 +/- 0.10 (+/- 1 standard deviation); the RVEF was less than 0.45 in 8 patients. With exercise the RVEF increased in 9 patients and either failed to increase or decreased in 15 (including all 8 patients with resting values less than 0.45). The weight-adjusted work load performed was a first predictor of RV exercise response (sensitivity 87%, specificity 92%); patients whose RVEF increased did more work. The mean resting left (pulmonary) ventricular (LV) EF was 0.58 +/- 0.09; the LVEF was less than 0.50 in 3 patients. With exercise the LVEF increased in 14 patients and did not increase in 10 (including all 3 with resting values less than 0.50). The presence of complex ventricular arrhythmia documented on Holter monitoring was a first predictor of failure of the LVEF to increase with exercise (sensitivity 84%, specificity 71%). The patient's age, operative age, postoperative interval, residual arterial desaturation, preoperative large ventricular septal defect or pulmonary stenosis, postoperative pulmonary stenosis or superior vena caval obstruction, or performance of a second open-heart procedure was predictive of the rest or exercise EF of either ventricle.

Adolescent↗
PubMed1983

Exercise studies after the Mustard operation in transposition of the great arteries.

Twenty-one postoperative patients with transposition of the great arteries (TGA) underwent graded exercise testing 4 to 15 years (mean 9) after the Mustard operation. No patient had subjective exercise intolerance before testing, although some had symptomatic resting arrhythmias. Correlations were made between cardiac catheterization data and 24-hour ambulatory monitoring. Exercise tolerance was diminished in nearly half of the patients. No statistically significant differences were found in heart rate or blood pressure responses, but maximal oxygen consumption values were lower than the control values (p less than 0.001) in the larger patients. Arrhythmias were present or provoked in most patients during exercise testing. Only 28% remained in normal sinus rhythm during and after exercise. Multifocal premature contractions were the most serious arrhythmias demonstrated. Some long-term survivors of the Mustard operation may have abnormal exercise dynamics, even though they may be asymptomatic and have normal physical activities and endurance. Mean maximal systolic blood pressure, heart rate, oxygen consumption, and maximal treadmill times were consistently in the low-normal range or were statistically lower than normal.

Adolescent↗
PubMed1983

Arrhythmias in transposition of the great arteries after the Mustard operation.

Disorders of rhythm or conduction in patients with transposition of the great arteries (TGA) after the Mustard operation have been widely reported. This study provides a systematic evaluation of the electrophysiologic function of 87 survivors of the Mustard operation at a single institution. Surface electrocardiograms were reviewed in all 87 patients, Holter monitoring data in 26 patients, exercise electrocardiograms in 21 patients, and invasive electrophysiologic data in 61 patients. Surface electrocardiograms showed normal sinus rhythm in 52%, sinus node dysfunction in 27%, and atrioventricular block in 16%. Holter monitoring was obtained in an unselected subgroup of 26 patients who had a mean age of 12 years and a mean interval from operation of 9 years. Sinus node dysfunction was found in 58%, atrioventricular block in 27% ventricular ectopy in 50%, supraventricular ectopy in 27%, and no abnormalities in only 8%. Intracardiac electrophysiologic evaluation showed a high frequency of abnormal sinus node recovery times and suboptimal response of the atrioventricular-conduction system to rapid atrial pacing. When all modalities used in this study were considered, sinus node dysfunction occurred in 47%, ectopy in 34% and atrioventricular block in 23%. Although only 30% of patients had no evidence of arrhythmia, symptoms of rhythm or conduction disturbances were rare.

Adolescent↗
PubMed1983

The anatomical heterogeneity of hearts lacking a patent communication between the left atrium and the ventricular mass ('mitral atresia') in presence of a patent aortic valve.

Thirty-five hearts were studied with no patent communication between the left atrium and the ventricular mass ('mitral atresia'). In ten, an imperforate and hypoplastic membrane separated the left atrium from a hypoplastic left ventricle. The imperforate valve ranged from a tiny membrane with no evidence of tension apparatus, through a larger membrane supported by muscular columns in the ventricular inlet portion, to an aneurysmal imperforate sac attached to a single hypoplastic papillary muscle. The ventriculo-arterial connection was concordant in nine of the ten hearts and double outlet from the right ventricle in one. In one further heart, there was double inlet left ventricle with imperforate left atrioventricular valve, a rudimentary right ventricle and ventriculo-arterial discordance. In the other 24 hearts the muscular floor of the left atrium was completely separated by the atrioventricular sulcus from the ventricular mass (absent left atrioventricular connection). In 11 of these hearts, the right atrium was connected to a right ventricle and there was a posterior and left-sided rudimentary left ventricular chamber which had no connection with the atrial chambers. The left ventricle supported the aorta in five of the 11 hearts, but in the other six it was simply a pouch of left ventricular morphology. In ten cases the right atrium was connected to a dominant left ventricle. An anterior rudimentary right ventricle was present in each but had no connection with the atrial chambers. It was to the left of the left ventricle in seven, directly anterior in one and to the right in two cases. The right ventricle supported the aorta in eight cases, the pulmonary trunk in one and neither great artery in the remaining case. Lastly, there were three cases in which a sole ventricular chamber of indeterminate morphology was present and gave rise to both great arteries.

Aortic Valve↗