Biomedical subjects
Publications and source records attributed to C Wren.
Successful balloon valvotomy in an adult with calcific pulmonic stenosis is described. The incidence of calcification, and the potential use of this technique in calcified pulmonary valves is discussed.
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Balloon dilation of recoarctation of the aorta was performed 47 times in 44 patients 49 +/- 54 months after surgical repair. The initial operation was performed in the neonatal period in 29 patients (66%). The age at balloon dilation was 4.9 +/- 5.3 years (range 2 months to 20 years) and weight was 18 +/- 15 kg (range 2 to 72). Systolic pressure difference across the recoarctation site decreased from 37 +/- 16 to 14 +/- 11 mm Hg and coarctation/aortic diameter ratio increased from 0.45 +/- 0.14 to 0.85 +/- 0.16 immediately after balloon dilation regardless of the nature of the previous operation (subclavian flap [n = 12], resection with end to end anastomosis [n = 21], patch angioplasty [n = 4] or multiple operations [n = 5]). In the ascending aorta, systolic pressure decreased from 120 +/- 25 to 113 +/- 20 mm Hg. In the descending aorta, systolic pressure increased from 85 +/- 15 to 100 +/- 19 mm Hg and pulse pressure increased from 22 +/- 7 to 36 +/- 8 mm Hg. At repeat cardiac catheterization in 21 patients (48%) 12 +/- 8 months after balloon dilation, there was further reduction in systolic pressure difference from 17 +/- 11 to 12 +/- 9 mm Hg with no further change in coarctation/aortic diameter ratio. Aneurysm formation was evident in one patient (2%) immediately after balloon dilation; the aneurysm was unchanged at repeat study 15 months later. A "new" aneurysm was apparent in 2 (10%) of the other 20 patients restudied to date. The occurrence of aneurysm in these three patients was unrelated to balloon size. There were no procedure-related deaths. Three patients (7%) had femoral artery occlusion. Balloon dilation affords good relief of obstruction without adverse sequelae from aortic wall disruption at medium-term follow-up.
Truncus arteriosus (type II) with interrupted aortic arch (type B) was successfully repaired at 11 days of age using anterior translocation of the pulmonary arteries, resection of the ductus arteriosus, and direct anastomosis between the descending aorta and truncus. This technique permitted wide reconstruction of the aortic arch and minimized the number of suture lines. It also positioned the right ventricle-pulmonary artery conduit anteriorly, which may simplify its subsequent replacement.
Percutaneous balloon dilatation of a stenosed Ionescu-Shiley bioprosthesis in the tricuspid valve position was performed twice in a 19 year old woman. On each occasion there was a considerable improvement in symptoms and haemodynamic function but the effect lasted for only a few months. When the valve was excised it showed no evidence of the previous balloon dilatations.
Balloon dilatation of the aortic valve was attempted in 34 consecutive children aged 16 months to 17 years (median 7 years), weight range 9-60 (median 22) kg. Previous surgical valvotomy had been performed in two patients (twice in one of them). The valve was not crossed in one patient. In the remaining 33 patients the pressure difference between the left ventricle and the ascending aorta during systole was reduced from 71 (30) to 28 (19) mm Hg. In 24 patients recatheterisation 2-19 (mean 9) months later showed gradients that were similar to those immediately after balloon dilatation (35 (20) v 31 (20) mm Hg). The two patients with the highest residual gradients immediately after balloon dilatation showed a spontaneous reduction in gradient at repeat catheterisation, whereas the patient who had twice had previous surgical valvotomy showed an increase in gradient from 37 to 99 mm Hg over nine months and required aortic root replacement. Balloon dilatation was repeated in two patients and this caused a further reduction in gradient. New aortic regurgitation occurred in nine (27%) patients (grade I, 8; grade II, 1) and aortic regurgitation was exacerbated (grade I to II) in two of the nine with pre-existing aortic regurgitation. External iliac artery avulsion occurred in one (3%) patient and two (6%) required intravenous streptokinase because the femoral artery became occluded. There were no other complications. Open valvotomy was performed in the child in whom the valve was not crossed, but no other child required aortic valve operation. Balloon dilatation of the aortic valve gave reasonable short term palliation and was well tolerated. It is an alternative to surgical valvotomy for initial palliation of congenital aortic stenosis in many children.
Twenty three patients with fragile X syndrome underwent cardiovascular assessment. Echocardiography showed dilatation of the aortic root in 12 (52%) and mitral valve prolapse in five (22%), four of whom had an apical mid-systolic click on auscultation. Patients with fragile X syndrome have cardiac defects similar to those seen in other disorders of connective tissue such as Marfan's syndrome and Ehlers-Danlos syndrome. These, and other somatic features, suggest an underlying connective tissue dysplasia.
Myocardial infarction and left ventricular failure developed within hours of ligation of a large arterial duct in a four week old infant. Anomalous origin of the left coronary artery from the pulmonary artery was confirmed by echocardiography. Despite emergency translocation of the anomalous coronary artery the patient died.
A 27 year old man developed multiple ventricular septal defects and a coronary artery ventricular fistula after a blunt injury. These were treated successfully by surgery, which was carried out four months after the injury to allow some healing of the defect to occur.
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We compared a rapid respiratory syncytial virus (RSV) antigen enzyme immunoassay (EIA) (Abbott Diagnostics, North Chicago, Ill.) with virus culture and with the indirect fluorescent-antibody test (FAT) by using nasopharyngeal washings from children with suspected RSV pneumonia or bronchiolitis. Fresh washings were used in all three tests. Specimens were inoculated into HEp-2 cells and human embryonic lung fibroblasts and observed for cytopathic effect. Cells in the centrifuged sediments of the nasal washes were examined for typical cytoplasmic fluorescence of RSV by FAT. The EIA cutoff was an optical density (OD) at 492 nm that was greater than the mean OD of the negative controls plus 0.1. An OD within +20% of the cutoff was considered borderline, and these specimens were retested. Of 289 specimens, 118 (41%) were positive by culture, 150 (52%) were positive by FAT, and 154 (53%) were positive by EIA. Eight borderline EIAs were all negative when the specimens were retested after storage at -70 degrees C. Of 17 specimens positive by EIA but negative by culture and FAT, 9 were blocked in a competitive EIA, indicating that they were true-positives and that the culture and FAT were falsely negative. The sensitivity, specificity, and predictive value (positive) of the EIA versus culture, FAT, or blocking assay were 90, 94, and 95%, respectively. We conclude that the Abbott RSV antigen EIA is highly sensitive and specific.
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Between 1979 and 1986, 26 patients with pulmonary atresia, ventricular septal defect, and multifocal pulmonary blood supply underwent surgery (median age, 2 years) to reconnect major aortopulmonary collateral arteries to other collateral arteries or to the central pulmonary arteries in an attempt to prepare the pulmonary circulation for complete repair. In four patients, central pulmonary arteries were found to be absent at exploratory thoracotomy, and therefore, the surgery aimed for optimal palliation. Four (15%) patients died perioperatively. The survivors had symptomatic improvement. At restudy 1 week-110 months (median time, 25 months) postoperatively, modest growth of central pulmonary arteries had occurred [right plus left pulmonary artery diameters/descending aortic diameter from 0.64 +/- 0.61 (mean +/- SD) preoperatively to 0.95 +/- 0.60 postoperatively (p less than 0.01)], with a greater number of bronchopulmonary segments connected to central pulmonary arteries [from 6.3 +/- 4.8 preoperatively to 10.0 +/- 4.5 postoperatively (p less than 0.001)]. However, only seven (27%) patients met the established criteria for repair, of whom three (12%) have undergone definitive surgery. Thirteen (50%) patients are unsuitable for repair, and two (8%) await restudy. Failure of anastomoses involving major aortopulmonary collateral arteries (13 of 33) was higher than for grafts from a systemic artery to the central pulmonary artery (1 of 22, p = 0.003). Failure was not related to the number of anastomoses per operation, suggesting that poor distal runoff may have been responsible. This surgical approach provided reasonable palliation but was rarely effective as a prelude to complete repair.(ABSTRACT TRUNCATED AT 250 WORDS)
Standard electrocardiograms from 126 consecutive patients with atrial isomerism were reviewed. Of 67 patients with left isomerism, 49 had sinus rhythm, 8 nodal rhythm and 10 atrioventricular (AV) block. Fifty-eight of 59 patients with right isomerism had sinus rhythm. Complete AV block was significantly more frequent in association with AV septal defect in left isomerism (5 of 45 patients) than in right isomerism (0 of 47 patients, p = 0.049). The P-wave axis was superior in 49% of patients with left isomerism but did not correlate with abnormalities of systemic or pulmonary venous connection. A significant shift of P-wave axis (more than 90 degrees) was seen on a subsequent electrocardiogram in 14 of 44 patients (32%) with left isomerism and 2 of 16 (13%) with right isomerism. Ambulatory electrocardiographic monitoring in 17 patients (14 with left isomerism) showed that only 4 had sinus rhythm throughout 24 hours. Only 1 patient with complete AV block received a permanent pacemaker. Despite the high incidence of electrocardiographic abnormalities, significant arrhythmias appear to be rare. The arrhythmias apparently do not influence the natural history of this condition or affect the outcome of palliative or corrective surgery. The prognosis is determined mainly or solely by the associated anatomic abnormalities.
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His bundle tachycardia is a rare arrhythmia in infants and children and is resistant to therapy. There is now sufficient evidence from reported cases and a further patient reported below to suggest that drug management of this arrhythmia is a reasonable alternative to His bundle ablation with life-long pacing from infancy.
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Flecainide acetate was administered intravenously and orally to 12 consecutive children, aged 1-15 years, presenting with arrhythmias that were life threatening or resistant to conventional medical treatment. Three children had arrhythmias related to Wolff-Parkinson-White syndrome, four had concealed accessory pathways, two had His bundle tachycardia, and three had ventricular tachycardia. Of seven patients who were given flecainide intravenously, four returned to sinus rhythm and in a fifth successful rate control of His bundle tachycardia was achieved. All 12 patients were given the drug orally: in nine it was successful in preventing recurrence of arrhythmia, in one satisfactory rate control was achieved, and in two it was withdrawn because it produced more frequent attacks of tachycardia. No other adverse effects occurred. The efficacy and low toxicity of treatment in this study suggests that flecainide acetate may have an important role in the management of selected paediatric arrhythmias.