Evolution of risk factors influencing early mortality of the arterial switch operation.
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OBJECTIVES: The present study was undertaken to determine the independent risk factors for early mortality in the current era after arterial switch operation (ASO). BACKGROUND: Prior reports on factors affecting outcome of the ASO demonstrated that abnormal coronary arterial patterns were associated with increased risk of early mortality. As diagnostic, surgical and perioperative management techniques continue to evolve, the risk factors for the ASO may have changed. METHODS: All patients who underwent the ASO at Children's Hospital, Boston between January 1, 1992 and December 31, 1996 were included. Hospital charts, echocardiographic and cardiac catheterization data and operative reports of all patients were reviewed. Demographics and preoperative, intraoperative and postoperative variables were recorded. RESULTS: Of the 223 patients included in the study (median age at ASO = 6 days and median weight = 3.5 kg), 26 patients had aortic arch obstruction or interruption, 12 had Taussig-Bing anomaly, 12 had multiple ventricular septal defects, 8 had right ventricular hypoplasia and 6 were premature. There were 16 early deaths (7%), with 3 deaths in the 109 patients considered "low risk" (2.7%). Coronary artery pattern was not associated with an increased risk of death. Compared with usual coronary anatomy pattern, however, inverted coronary patterns and single right coronary patterns were associated with increased incidence of delayed sternal closure (p = 0.003) and longer duration of mechanical ventilation (p = 0.008). In a multivariate logistic regression model using only preoperative variables, aortic arch repair at a separate procedure before ASO and smaller birth weight were independent predictors of early mortality. In a second model that included both pre- and intraoperative variables, circulatory arrest time and right ventricular hypoplasia were independent predictors of early death. CONCLUSIONS: The ASO can be performed in the current era without excess early mortality related to uncommon coronary artery patterns. Aortic arch repair before ASO, right ventricular hypoplasia, lower birth weight and longer intraoperative support continue to be independent risk factors for early mortality after the ASO. (+info)
Troponin-I for prediction of early postoperative course after pediatric cardiac surgery.
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OBJECTIVES: It was the aim of the study to test the prognostic value of cardiac troponin-I (cTnI) concerning the early postoperative course after pediatric cardiac surgery. BACKGROUND: Cardiac troponin-I is a very specific and sensitive marker of myocardial damage in adults and children. As perioperative myocardial damage may be a significant factor of postoperative cardiac performance, serial cTnI values were analyzed in children undergoing open heart surgery. METHODS: Seventy-three children undergoing elective correction of congenital heart disease including atrial and ventricular surgical manipulation were studied. Cardiac troponin-I levels were measured serially and correlated with intra- and postoperative parameters (such as doses and length of inotropic support, renal and hepatic function, duration of intubation). Patients with prolonged postoperative recovery were analyzed with special attention to the cTnI levels. RESULTS: The cutoff point for the definition of a high and a low risk group of cTnI values was set at 25 microg/liter, 4 h after admission to the intensive care unit (ICU) and at 35 microg/liter considering the maximal value of cTnI in the first 24 h in the ICU. The results showed a highly significant correlation between the need for inotropic support, the severity of renal dysfunction and the duration of intubation in relation to the serum levels of cTnI. CONCLUSIONS: Cardiac troponin-I serum levels after open heart surgery in children and infants 4 h after admission to the ICU allowed anticipation of the postoperative course and correlated with the incidence of significant postoperative complications. (+info)
Elevated plasma levels of adrenomedullin in congenital cyanotic heart disease.
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Adrenomedullin is a novel hypotensive peptide originally isolated from human pheochromocytoma. Accumulating evidence suggests the possible involvement of adrenomedullin in the physiology of the pulmonary circulation and the pathophysiology of hypoxaemia. The aim of the present study was to investigate the pathophysiological significance of adrenomedullin in hypoxaemia caused by congenital cyanotic heart disease. Subjects were 16 patients with congenital cyanotic heart disease aged 0.8-10 years (Group C) and 12 age-matched control subjects (patients with coronary artery dilatation after Kawasaki disease; Group N). Plasma adrenomedullin concentrations were measured, using radioimmunoassay, in femoral venous, pulmonary arterial and pulmonary venous blood obtained during cardiac catheterization. Plasma adrenomedullin concentrations in Group C were significantly (3-fold) higher than those in Group N at all sampling sites. In Group C, plasma adrenomedullin concentrations in pulmonary venous blood were significantly lower than those in pulmonary arterial blood. Pulmonary uptake of adrenomedullin in Group C was significantly greater than that in Group N. Patients with congenital cyanotic heart disease showed elevated plasma adrenomedullin concentrations and an increased uptake of adrenomedullin in the pulmonary circulation, which may act to dilate pulmonary vessels and increase pulmonary blood flow to alleviate hypoxaemia. Intrinsically increased adrenomedullin levels may function as a compensatory mechanism for hypoxaemia in congenital cyanotic heart disease. (+info)
Fate of the stented arterial duct.
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BACKGROUND: The technical aspects of ductal stenting have been reported, but little is known of the fate of the duct after stent implantation. METHODS AND RESULTS: Nineteen patients underwent stent implantation to maintain ductal patency. Eight had hypoplastic left heart (HLH) syndrome, 10 had pulmonary atresia, and 1 had tricuspid atresia. Median survival with HLH was 57 (12 to 907) days. Stent implantation was successful in all cases of HLH, but there were no long-term survivors. Two well-palliated infants died at transplantation. Median survival with duct-dependent pulmonary flow was 183 (0 to 1687) days, with 3 patients well at latest follow-up (56, 55, and 9 months, respectively). There were 2 operative deaths due to ductal spasm and 4 late deaths, 1 due to duct thrombosis, 1 due to chronic lung disease, and 2 of unknown cause. Stent implantation failed in 4 of the 11 cases. Assessment of endothelialization was possible in 13 cases; the stent was partially covered in 3 and fully endothelialized in all 10 cases assessed >8 weeks after implantation. In patients stented for inadequate pulmonary flow, ductal intimal hyperplasia occurred by 9 months in all 3 survivors but responded to repeated dilation. CONCLUSIONS: Ductal stenting cannot be recommended. In patients with HLH, it provides only short-term palliation even when combined with pulmonary artery banding. With duct-dependent pulmonary blood flow, the procedure carries high risk, and duration of palliation is poor. In patients with bilateral ducts and absent central pulmonary arteries, good palliation may be achieved, but repeated angioplasty is necessary to counteract intimal hyperplasia. (+info)
Critical pathways for postoperative care after simple congenital heart surgery.
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OBJECTIVE: To evaluate the clinical, financial, and parent/patient satisfaction impact of critical pathways on the postoperative care of pediatric cardiothoracic patients with simple congenital heart lesions. STUDY DESIGN: Critical pathways were developed by pediatric intensive care nurses and implemented under the direction of pediatric cardiothoracic surgeons. PATIENTS AND METHODS: Critical pathways were used during a 12-month study on 46 postoperative patients with simple repair of atrial septal defect (ASD), coarctation of the aorta (CoA), and patent ductus arteriosus (PDA). Using the study criteria, a control group of 58 patients was chosen from 1993. Prospective and control group data collected included postoperative intubation time, total laboratory tests, arterial blood gas utilization, morphine utilization, time in the pediatric intensive care unit, total hospital stay, total hospital charges, total hospital cost, and complications. Variances from the critical pathway and satisfaction data were also recorded for study patients. RESULTS: Resource utilization was reduced after implementation of critical pathways. Significant reductions were seen in total hours in the pediatric intensive care unit, total number of laboratory tests, postoperative intubation times, arterial blood gas utilization, morphine utilization, length of hospitalization (ASD, 4.9 to 3.1 days; CoA, 5.2 to 3.2 days; and PDA, 4.1 to 1.4 days; all P < 0.05), total hospital charges (ASD, $16,633 to $13,627; CoA, $14,292 to $8319; and PDA, $8249 to $4216; all P < 0.05), and total hospital costs. There was no increase in respiratory complications or other complications. Patients and families were generally satisfied with their hospital experience, including analgesia and length of hospitalization. CONCLUSIONS: Implementation of critical pathways reduced resource utilization and costs after repair of three simple congenital heart lesions, without obvious complications or patient dissatisfaction. (+info)
The role of the brachyury gene in heart development and left-right specification in the mouse.
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The midline has a theoretical role in the development of left-right asymmetry, and this is supported by both genetic analyses and experimental manipulation of midline structures in vertebrates. The mouse brachyury (T) gene encodes a transcription factor which is expressed in the developing notochord and is required for its development. T/T mice lack a mature notochord and have a dorsalised neural tube. We have examined the hearts of T/T mice and have found consistent morphological abnormalities, resulting in ventrally displaced ventricular loops, and a 50% incidence of inverted heart situs. Three TGF-beta related genes, lefty-1, lefty-2 and nodal, are expressed asymmetrically in mouse embryos, and are implicated in the development of situs. We find that nodal, which is normally expressed around the node and in left lateral plate mesoderm in early somite embryos, is completely absent at this stage in T/T embryos. In contrast, lefty-1 and lefty-2, which are normally expressed in the left half of prospective floorplate and left lateral plate mesoderm, respectively, are both expressed in T/T embryos only in a broad patch of ventral cells in, and just rostral to, the node region. These results implicate the node as a source of instructive signals driving expression of nodal and lefty-2 in the left lateral plate mesoderm, and being required for normal looping and situs of the heart. (+info)
A novel role for cardiac neural crest in heart development.
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Ablation of premigratory cardiac neural crest results in defective development of the cardiac outflow tract. The purpose of the present study was to correlate the earliest functional and morphological changes in heart development after cardiac neural crest ablation. Within 24 hours after neural crest ablation, the external morphology of the hearts showed straight outflow limbs, tighter heart loops, and variable dilations. Incorporation of bromodeoxyuridine in myocytes, an indication of proliferation, was doubled after cardiac neural crest ablation. The myocardial calcium transients, which are a measure of excitation-contraction coupling, were depressed by 50% in both the inflow and outflow portions of the looped heart tube. The myocardial transients could be rescued by replacing the cardiac neural crest. The cardiac jelly produced by the myocardium was distributed in an uneven, rather than uniform, pattern. An extreme variability in external morphology could be attributed to the uneven distribution of cardiac jelly. In the absence of cardiac neural crest, the myocardium was characterized by somewhat disorganized myofibrils that may be a result of abnormally elevated proliferation. In contrast, endocardial development appeared normal, as evidenced by normal expression of fibrillin-2 protein (JB3 antigen) and normal formation of cushion mesenchyme and trabeculae. The signs of abnormal myocardial development coincident with normal endocardium suggest that the presence of cardiac neural crest cells is necessary for normal differentiation and function of the myocardium during early heart development. These results indicate a novel role for neural crest cells in myocardial maturation. (+info)
Bubble contrast echocardiography in detecting pulmonary arteriovenous shunting in children with univentricular heart after cavopulmonary anastomosis.
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OBJECTIVES: We sought to compare bubble contrast echocardiography and pulmonary angiography in detecting pulmonary arteriovenous malformation (PAVM) in children with cavopulmonary anastomosis (CPA), and to examine anatomic and physiologic variables associated with the development of PAVM. BACKGROUND: Development of PAVM in patients with CPA may cause profound cyanosis. Pulmonary arteriovenous malformation has been traditionally diagnosed by pulmonary angiography with reported incidence of 20% to 25% in patients with CPA. METHODS: Fourteen patients (age 1.1 to 12.6 years) with any forms of CPA and normal pulmonary venous drainage formed the study population. All patients underwent cardiac catheterization and pulmonary angiography. Bubble contrast echocardiographic studies were performed with injection of 10 ml of agitated saline solution into branch pulmonary arteries. Transthoracic echocardiograms using an apical view were performed to assess the appearance of bubble contrast in the systemic ventricles. We compared the results of pulmonary angiograms and contrast echocardiograms, and findings of contrast echocardiograms between lungs with hepatic venous blood flow and lungs without hepatic venous blood. RESULTS: Ten of the 14 patients (71%) had positive contrast echocardiographic studies, compared with three (21%) detected by pulmonary angiograms (p = 0.01). No difference was found in pulmonary artery pressure, transpulmonary gradient or presence of heterotaxy syndrome between patients with positive contrast echocardiographic studies and patients with negative studies. However, patients with positive contrast echocardiograms tended to have lower oxygen saturation (81%) and higher hemoglobin (16.4 g/dl) compared with patients with negative studies (88% and 14.7 g/dl, p = 0.10 and p = 0.18 respectively). Patients with Glenn shunt or unidirectional Fontan had higher incidence of PAVM (10/11) compared with patients with classic or lateral tunnel Fontan (0/3, p = 0.01). All 12 lungs with no perfusion of hepatic venous blood had positive contrast echocardiographic studies. Lungs with no hepatic venous blood flow were more likely to develop PAVM compared with lungs with hepatic venous blood flow (12/12 and 3/16 respectively, p < 0.01). CONCLUSIONS: Bubble contrast echocardiography is more sensitive in detecting PAVM compared with pulmonary angiography. The prevalence of PAVM in patients with CPA may be much higher than what had been reported previously. Lungs with no hepatic venous blood flow are more likely to develop PAVM than lungs with hepatic venous blood flow. (+info)