Objectives. The objective of this study was to show elevations in septal shear stress in response to morphologic abnormalities that have been associated with discrete subaortic stenosis (SAS) in ...children. Combined with the published data, this critical connection supports a four-stage etiology of SAS that is advanced in this report.
Background. Subaortic stenosis constitutes up to 20% of left ventricular outflow obstruction in children and frequently requires surgical removal, and the lesions may reappear unpredictably after the operation. The etiology of SAS is unknown. This study proposes a four-stage etiology for SAS that I) combines morphologic abnormalities, II) elevation of septal shear stress, III) genetic predisposition and IV) cellular proliferation in response to shear stress.
Methods. Morphologic structures of a left ventricular outflow tract were modeled based on measurements in patients with and without SAS. Septal shear stress was studied in response to changes in aortoseptal angle (AoSA) (120° to 150°), outflow tract convergence angle (45°, 22.5° and 0°), presence/location of a ventricular septal defect (VSD) (3-mm VSD; 2 and 6 mm from annulus) and shunt velocity (3 and 5 m/s).
Results. Variations in AoSA produced marked elevations in septal shear stress (from 103 dynes/cm2for 150° angle to 150 dynes/cm2for 120° angle for baseline conditions). This effect was not dependent on the convergence angle in the outflow tract (150 to 132 dynes/cm2over full range of angles including extreme case of 0°). A VSD enhanced this effect (150 to 220 dynes/cm2at steep angle of 120° and 3 m/s shunt velocity), consistent with the high incidence of VSDs in patients with SAS. The position of the VSD was also important, with a reduction of the distance between the VSD and the aortic annulus causing further increases in septal shear stress (220 and 266 dynes/cm2for distances of 6 and 2 mm from the annulus, respectively).
Conclusions. Small changes in AoSA produce important changes in septal shear stress. The levels of stress increase are consistent with cellular flow studies showing stimulation of growth factors and cellular proliferation. Steepened AoSA may be a risk factor for the development of SAS. Evidence exists for all four stages of the proposed etiology of SAS.
(J Am Coll Cardiol 1997;30:247–54)
Pulmonary embolism is an uncommon but potentially life threatening disease in children and adolescents. The clinical findings can be similar to other more common conditions such as pneumonia. ...Therefore high level of suspicion is required for early and accurate diagnosis. Most children have at least one underlying risk factor, either inherited or acquired. Computed tomography is the most widely used method in diagnosing pulmonary embolism. Anticoagulation is the mainstay of therapy for pulmonary embolism, however, acute surgery may be required for removal of the embolism. We report a case of pulmonary embolism in a teenage girl with serious circulatory failure where emergency surgery was needed.
Sengers syndrome is characterized by congenital cataracts, hypertrophic cardiomyopathy, mitochondrial myopathy, and lactic acidosis, but no abnormalities have been found with routine mitochondrial ...biochemical diagnostics (the determination of pyruvate oxidation rates and enzyme measurements). In immunoblot analysis, the protein content of the mitochondrial adenine nucleotide translocator 1 (ANT1) was found to be strongly reduced in the muscle tissues of two unrelated patients with Sengers syndrome. In addition, low residual adenine nucleotide translocator activity was detected upon the reconstitution of detergent‐solubilized mitochondrial extracts from the patients' skeletal or heart muscle into liposomes. Sequence analysis and linkage analysis showed that ANT1 was not the primary genetic cause of Sengers syndrome. We propose that transcriptional, translational, or posttranslational events are responsible for the ANT1 deficiency associated with the syndrome.
About 1% of live-born children have congenital malformations of the heart. The aim of our study was to investigate the incidence of such defects in children born in Iceland during a period of 10 ...years, extending from 1990 through 1999.
Information about the patients was obtained from medical records from two hospitals that cover the whole country, a private clinic of pediatric cardiologists, an echocardiography database, autopsy reports, and death certificates. We investigated the distribution of specific malformations, the age at diagnosis, the symptoms leading to the diagnosis, the source of referral, and treatment and quality of life.
Between 1990 and 1999, there were 44,013 live births in Iceland, of which 740 patients were diagnosed with congenital cardiac malformations, accounting for 1.7% of the live-born children. The distribution was made up of 338 patients with ventricular septal defect (45.7%), 90 with atrial septal defect (12.2%), 85 with patency of the arterial duct (11.5%), 48 with pulmonary valvar stenosis (6.5%), 38 with a bicuspid aortic valve (5.1%), 28 with aortic coarctation (3.8%), 22 with tetralogy of Fallot (3.0%), 14 with transposed great arteries (1.9%), 11 with aortic stenosis (1.5%), 10 with atrioventricular septal defect and common atrioventricular orifice (1.4%), 9 with mitral valvar regurgitation (1.2%), 7 with sub-aortic stenosis (0.9%), and 5 with hypoplasia of the left heart (0.7%). Extracardiac anomalies were seen in 89 patients (12.0%). Chromosomal defects were seen in 36 patients, of whom 28 had Down's syndrome.
The annual incidence of diagnosis of patients with congenital cardiac malformations increased during the period of study. This was noted for minor defects, but the incidence of the major anomalies did not alter. Our observed yearly incidence, at 1.7%, was higher than noted in a previous study covering the years 1985 through 1989, and is also higher than in other population-based studies. The most likely explanation is the fact that access to pediatric cardiologists in Iceland is very good. Diagnosis, registration, and follow-up are conducted by only a few cardiologists, and take place at a single center for pediatric cardiology.
Objective: Short-term survival after pediatric heart transplantation is now excellent, but ultimately the efficacy of this procedure will depend on duration and quality of survival. We sought to ...evaluate the clinical course of long-term survivors of heart transplantation in childhood.
Methods: Patients who had undergone heart transplantation at the university hospitals of Stanford, Columbia, and Pittsburgh between 1975 and 1989 and survived longer than 5 years from transplantation were identified and their clinical courses retrospectively reviewed.
Results: Sixty eight children have survived more than 5 years from transplantation, and 60 (88%) are currently alive with a median follow-up of 6.8 years (5 to 17.9 years). Thirteen have survived more than 10 years from transplantation. Renal dysfunction caused by immunosuppressive agents was common, and two patients required late renal transplantation. Lymphoproliferative disease or other neoplasm occurred in 12 patients, but none resulted in death. Coronary artery disease was diagnosed in 13 patients (19%), leading to retransplantation in eight. Death after 5 years was related to acute or chronic rejection in 5 of 8 cases. Two of the deaths were directly related to noncompliance with immunosuppressive medication (Table). All survivors are in New York Heart Association class 1.
Conclusions: Long-term survival with good quality of life can be achieved after heart transplantation in childhood, though complications of immunosuppression remain common. Posttransplantation coronary artery disease is emerging as the main factor limiting long term graft and patient survival. (J Pediatr 1997; 130:862-71)
Pediatric life support Thornórkelsson, Thornórethur; Bjoernsson, Hjalti Már; Sigfússon, Gunnlaugur
Laeknabladid
92, Številka:
11
Journal Article
Recenzirano
Diseases which result in respiratory failure or hypotension are the most common cause of cardiac arrest in children. Whereas heart diseases are the most common cause of cardiac arrest in adults, they ...are uncommon cause in children. Accidents are the most common cause of out-of-hospital cardiac arrest. Prompt and skilled resuscitation efforts are important for favourable resuscitation outcome. This article provides guidelines for resuscitation in children from one month of age for health care providers. They are mainly based of recently published International Liaison Committee on Resuscitation (ILCOR) guidelines on resuscitation in children.
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