Char syndrome, an inherited disorder with patent ductus arteriosus, maps to chromosome 6p12-p21.
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BACKGROUND: Patent ductus arteriosus (PDA) is a relatively common form of congenital heart disease. Although polygenic inheritance has been implicated, no specific gene defects causing PDA have been identified to date. Thus, a positional cloning strategy was undertaken to determine the gene responsible for the Char syndrome, an autosomal dominant disorder characterized by PDA, facial dysmorphism, and hand anomalies. METHODS AND RESULTS: A genome scan was performed with 46 members of 2 unrelated families in which the disease was fully penetrant but the phenotype differed. Significant linkage was achieved with several polymorphic DNA markers mapping to chromosome 6p12-p21 (maximal 2-point LOD score of 8.39 with D6S1638 at theta=0.00). Haplotype analysis identified recombinant events that defined the Char syndrome locus with high probability to a 3. 1-cM region between D6S459/D6S1632/D6S1541 and D6S1024. CONCLUSIONS: A familial syndrome in which PDA is a common feature was mapped to a narrow region of chromosome 6p12-p21. Additional analysis with other families and polymorphic markers as well as evaluation of potential candidate genes should lead to the identification of the Char syndrome gene, which will provide insights into cardiogenesis as well as limb and craniofacial development. (+info)
Effect of nebulized epoprostenol (prostacyclin) on exhaled nitric oxide in patients with pulmonary hypertension due to congenital heart disease and in normal controls.
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Inhaled epoprostenol (prostacyclin) may be used in the treatment of severe pulmonary hypertension, improving oxygenation and reducing pulmonary artery pressures. We have observed symptomatic benefits of epoprostenol in patients with congenital heart disease that extend beyond acute haemodynamic effects of the drug, which has a short biological half-life. The aim of this study was to examine the effects of epoprostenol in patients and normal subjects on exhaled nitric oxide (eNO), based on the hypothesis that the drug may alter the resting vasoconstrictor/vasodilator balance. Nine patients with pulmonary hypertension complicating left-to-right cardiac shunts and nine healthy controls received 100 microgram of nebulized epoprostenol. Exhaled eNO was measured, using a chemiluminescence method, before, immediately after and 18 h after nebulization. There was no significant difference between the two groups in baseline eNO or eNO immediately following nebulized epoprostenol. Epoprostenol produced a delayed elevation in eNO 18 h after nebulization in patients, but not in normal controls. This study supports the concept that epoprostenol, while having no effect on the normal pulmonary circulation, acts on the hypertensive circulation via a mechanism that may result in a delayed alteration of vasoconstrictor/vasodilator balance. (+info)
Aortic obstruction caused by device occlusion of patent arterial duct.
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A 2 year old girl is reported in whom deployment of the Amplatzer ductal occluder caused significant aortic obstruction, requiring surgical removal of the device. This case emphasises the need for careful echocardiographic and angiographic assessment of the position of the Amplatzer ductal occluder before and after detaching the device from its delivery system, with particular emphasis on the position of the aortic retention ring. Careful assessment of ductal anatomy must guide case selection. (+info)
Postnatal hemodynamic changes in very-low-birthweight infants.
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The purpose of this study was to characterize postnatal changes in regional Doppler blood flow velocity (BFV) and cardiac function of very-low-birthweight infants and to examine factors that might influence these hemodynamic changes. Mean and end-diastolic BFV of the middle cerebral and superior mesenteric arteries, cardiac output, stroke volume, and fractional shortening were measured in 20 infants birthweight 1,002 +/- 173 g, gestational age 28 +/- 2 wk) at 6, 30, and 54 h after birth and before and after feedings on days 7 and 14. Postnatal increases in cerebral BFV, mesenteric BFV, and cardiac output were observed that were not associated with changes in blood pressure, hematocrit, pH, arterial PCO(2), or oxygen saturation. The postnatal pattern of relative vascular resistance (RVR) differed between the cerebral and mesenteric vasculatures. RVR decreased in the middle cerebral but not the superior mesenteric artery. Physiological patency of the ductus arteriosus did not alter postnatal hemodynamic changes. In response to feeding, mesenteric BFV and stroke volume increased, and mesenteric RVR and heart rate decreased. Postprandial responses were not affected by postnatal age or the age at which feeding was initiated. However, the initiation of enteral nutrition before 3 days of life was associated with higher preprandial mesenteric BFV and lower mesenteric RVR than was later initiation of feeding. We conclude that in very-low-birthweight infants over the first week of life 1) systemic, cerebral, and mesenteric hemodynamics exhibit region-specific changes; 2) asymptomatic ductus arteriosus patency and early feedings do not significantly influence these postnatal hemodynamic changes; and 3) cardiac function adapts to increase local mesenteric BFV in response to feedings. (+info)
Stretching of the ductus: an important factor in determining the outcome of coil occlusion.
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The present study measured the minimal diameter of the ductus (minimal D), the stretched minimal diameter (stretched D), and the stretch index (SI) before coil occlusion in 25 patients with a patent arterial duct. The following factors were compared in the success group (22 cases, coil successfully placed after initial deployment) versus the failure group (3 cases): minimal D, stretched D, SI, the sum of the loop diameter of coils (the loop diameter), the sum of the product of the loop diameter and the number of loops (the loop diameter and number), the loop diameter/minimal D, the loop diameter/stretched D, the loop diameter and number/minimal D, and the loop diameter and number/stretched D. In the failure group, minimal D, stretched D, SI, the loop diameter, and the loop diameter and number were larger than in the success group. The loop diameter/stretched D, and the loop diameter and number/stretched D were smaller in the failure group. Although the loop diameter and number/minimal D was slightly smaller in the failure group, the loop diameter/minimal D was comparable. It is concluded that the stretched D is more reliable than minimal D to determine the appropriate size of coil for successful initial deployment. (+info)
Primary bronchomalacia and patent ductus arteriosus: simultaneous surgical correction in an infant.
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We report the clinical course of a 6-month-old girl with recurrent infection of the left lung, persistent wheezing, and a suspected congenital heart anomaly (patent ductus arteriosus. Chest radiography revealed hyperinflation and slight inflammation of the left lung. Tracheobronchoscopy and left-sided bronchography showed a collapsed segment of the left main bronchus, 3 cm long. Computed tomography confirmed hyperinflation of the left lung and atelectasis of the superior lobe. There were no signs of extramural compression. Color-flow Doppler echocardiography confirmed the suspicion of patent ductus arteriosus. To the best of our knowledge, there is no other report in the literature of a patient with this combination of anomalies. After receiving 2 weeks of antibiotic treatment, the patient underwent surgical repair The patent ductus arteriosus was closed by means of a triple-ligature procedure, and during the same operation a bronchopexy was performed, securing the left main bronchus to the closed ductus tissue by means of sutures. There have been no complications in the postoperative period. Clinical follow-up, as well as echocardiography and bronchoscopy, have yielded normal results 14 months after surgery. (+info)
Echocardiographic flow pattern of patent ductus arteriosus: a guide to indomethacin treatment in premature infants.
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AIM: To compare the efficacy and safety of an indomethacin treatment strategy based on serial echocardiographic measurement of patent ductus arteriosus (PDA) flow pattern with a standard protocol. METHODS: Neonates weighing less than 1500 g at birth, who required respiratory support, and who had developed symptomatic PDA, were studied. PDA was confirmed in all infants using colour Doppler echocardiography, and serial observations of the ductal flow pattern were made. Infants randomly assigned to receive conventional indomethacin treatment (protocol group) were given an initial dose of 0.2 mg/kg, followed by 0.1 or 0.2 mg/kg, depending on age, 12 hourly for two further doses, and were eligible for a second course. Those randomly assigned to the ductal flow pattern assessment (ECHO group) received further doses of indomethacin after 24 hours, only if their flow pattern was "pulsatile" or "growing." RESULTS: There was no significant difference in the primary outcome measures between the two groups. The closure rate was 89.1% and 87.2%, respectively, in the protocol and ECHO groups. The mean (SD) doses of indomethacin were significantly higher in the protocol group: 3.2 (1.4) doses compared with 1.6 (0.9) doses. There was a significantly higher incidence of hypoglycaemia, impaired urine output, and gastrointestinal bleeding in the protocol group. CONCLUSIONS: An indomethacin treatment strategy for PDA based on measurement of the ductal flow pattern is associated with a reduction in the total doses of indomethacin administered, and a reduced rate of complications, compared with a conventional protocol. There is no difference in closure rate. (+info)
Transcatheter coil embolization of large-size patent ductus arteriosus in adult patients: usefulness and problems.
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Transcatheter coil embolization of the patent ductus arteriosus (PDA) has been frequently used in children, especially for small lesions. It was attempted in 3 adults using Cook detachable coils. For 2 of the patients, relatively old age and heart failure were the reasons for choosing coil embolization of the PDA. In the remaining patient, who had Wolff-Parkinson-White syndrome, coil embolization was performed after radiofrequency catheter ablation of Kent's bundle. Their respective minimal PDA diameters were 5.0 mm, 4.5 mm and 4.0 mm measured by transesophageal echocardiography. Two coils were placed in 2 patients and 1 coil in the remaining patient. After the procedures, the size of the left ventricle decreased and heart failure was improved in 2 patients, although all 3 patients had a residual shunt, which caused hemolytic anemia in 2 patients. Repeat coil-embolization procedures resulted in complete occlusion and the hemolysis disappeared in these patients. In adult patients who have heart failure due to large PDA, coil embolization with detachable coils, even if residual shunt persists, is useful for improvement of the heart failure. In cases of hemolysis related to residual shunt, a second coil-embolization procedure can improve it completely. (+info)