Study of the conduction system in a population of patients with sudden infant death syndrome

Summary The conduction system of 23 infant hearts, 15 of sudden infant death syndrome (SIDS) and eight of those dying from known cause, was serially sectioned. A left-sided His bundle was found more commonly in (SIDS) (eight of 15) than in the controls (two of eight). Taking into account a previous study in which a left-sided His bundle was found in only four of 32 hearts from all age groups, this is statistically significant and may be a factor promoting SIDS.This research was aided by grant HL-30558-02 from the National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland.     

Role of congenital long-QT syndrome in unexplained sudden infant death: proposal for an electrocardiographic screening in relatives

Introduction  Congenital long-QT syndrome (LQTS) is a sporadic or familial inherited arrhythmia. It can lead to sudden death by ventricular fibrillation which occurs at any age but particularly during infancy. Recent studies of postmortem molecular analysis in infants who died of unexplained sudden infant death syndrome (SIDS) showed abnormal mutations to LQTS in 10% to 12%. Current methods of etiologic investigation of sudden infant death syndrome do not allow the diagnosis of LQTS. A targeted anamnesis together with systematic electrocardiograms of first- and second-degree relatives could be an efficient LQTS diagnostic tool. Therefore, we propose to include them in screening procedures for SIDS etiologies. Conclusion  LQTS accounts for a significant number of unexplained SIDS. We suggest adding a systematic familial electrocardiographic screening to the current etiologic investigations in order to track congenital LQTS in relatives.     

Formative evaluation to improve prevention of sudden infant death syndrome (SIDS): a prospective study

Aim: To evaluate formative evaluation, a pedagogic method that sensitizes mothers to sudden infant death syndrome (SIDS), as a new way to improve prevention of SIDS. Methods: Prospective and randomized study. Mothers in a test group (n = 148) received an educative questionnaire about SIDS during maternity stay. Three months later, we evaluated, by a telephonic interview, their scores of knowledge and observance of the recommendations in comparison with a control group (n = 144). Results: Mothers’ scores at the educative questionnaire was 5.12 (1.52) [mean(standard deviation)]. The scores performed 3 months later were better in test group for knowledge [7.64 (1.56) vs. 7.16 (1.61), p < 0.01] and for observance [8.28 (1.51) vs. 7.62 (1.72), p < 0.001]. Logistic regression analysis confirmed the benefits in test group regarding knowledge of SIDS risk factors [ORa = 1.69 (1.02–2.77), p < 0.05], of the advice to avoid overheating infants [ORa = 2.50 (1.43–4.38), p < 0.01] and of the risks of bed sharing [ORa = 2.7 (1.6–4.5), p < 0.001]. There was a significant association between non‐compliance with the sleeping position recommendation and unemployment (p < 0.01) and absence of postsecondary school education (p < 0.01). Conclusion: Formative evaluation using an educative questionnaire could improve maternal awareness on SIDS risk factors and their compliance with recommendations about SIDS prevention.     

Deformational brachycephaly in supine-sleeping infants

OBJECTIVES: Medical dictionaries and anthropologic sources define brachycephaly as a cranial index (CI = width divided by length x 100%) greater than 81%. We examine the impact of supine sleeping on CI and compare orthotic treatment with repositioning. STUDY DESIGN: We compared the effect of repositioning versus helmet therapy on CI in 193 infants referred for abnormal head shape. RESULTS: Eighty percent of the infants had a pretreatment CI > 81%. Their initial mean CI at mean age 5.3 months was 89%, and after treatment, their mean CI was 87% (+/-2 SE = 0.9%) at mean age 9.0 months. For 92 infants with an initial CI at or above 90%, their initial mean CI of 96.1% was reduced to a mean of 91.9%. CONCLUSIONS: Post-treatment CI was 86% to 88%, CI in neonates delivered by cesarean section was 80%, and CI in supine-sleeping Asian children was 85% to 91%, versus 78% to 83% for prone-sleeping American children. Repositioning was less effective than cranial orthotic therapy in correcting severe brachycephaly. We recommend varying the head position when putting infants to sleep.     

Serum testosterone and estradiol in sudden infant death

OBJECTIVE: To test the hypothesis that among infants who die unexpectedly, testosterone and/or estradiol levels are elevated in those diagnosed with SIDS versus those with known causes of death (controls). STUDY DESIGN: Postmortem blood was collected and coded from infant autopsies, and serum was prepared and frozen until assayed for total testosterone and estradiol by fluoroimmunoassay. Subject information was then collected from the medical examiner's report. RESULTS: Testosterone, but not estradiol, was significantly higher in 127 SIDS cases versus 42 controls for both males (4.8 +/- 0.4 vs 2.2 +/- 0.4 nmol, respectively; P < .005) and females (2.4 +/- 0.2 vs 1.6 +/- 0.2 nmol, respectively; P < 0.03). CONCLUSIONS: Higher testosterone levels in infant victims of unexpected, unexplained death may indicate a role for testosterone or related steroids in SIDS. Further research is needed to understand the potential utility of testosterone as an indicator of SIDS risk.     

Newborn screening in India

Expanded newborn screening (NBS) is aimed for early detection and intervention of treatable inborn errors of metabolism and also to establish incidence of these disorders in this part of the globe. The first expanded NBS programme initiated in the capital city of Andhra Pradesh to screen all the newborns born in four major Government Maternity Hospitals in Hyderabad by heel prick capillary blood collected on S&S 903 filter paper. Chromatographic (TLC and HPLC), electrophoretic (cellulose acetate and agarose) and ELISA based assays have been employed for screening of common inborn errors of metabolism. This study has shown a high prevalence of treatable Inborn errors of metabolism. Congenital hypothyroidsm is the most common disorder (1in1700) followed by congenital Adrenal Hyperplasia (1 in 2575) and Hyperhomocystenemia (1in100). Interestingly, a very high prevalence of inborn errors of metabolism to the extent of 1 in every thousand newborns was observed. The study reveals the importance of screening in India, necessitating nation wide large-scale screening.     

代谢性心肌病

心肌代谢活跃,代谢紊乱导致心肌能量产生不足,引起心肌病变。先天性代谢缺陷是儿童心肌病常见病因之一,表现为肥厚型或扩张型心肌病等类型,导致心力衰竭或心源性休克,甚至猝死。据报道,可引起心肌病的先天性代谢缺陷有40余种,包括脂肪酸氧化障碍、糖原累积病、溶酶体贮积病、线粒体病、有机酸血症、肌酸病和先天性糖基化障碍等。存在多系...     

Sudden infant death syndrome in Indigenous and non-Indigenous infants in north Queensland, 1990-1998

OBJECTIVE: To compare the epidemiology of sudden infant death syndrome (SIDS) in Indigenous and non-Indigenous infants in north Queensland, and to assess the quality of data recorded for SIDS deaths. METHODS: Records were obtained for SIDS cases from all coronial courts in north Queensland from 1990 to 1998. Demographic characteristics, ethnicity, age at death, sleeping and feeding patterns, smoking incidences and autopsy findings were compared. Incidences, medians and univariate associations were generated where appropriate. RESULTS: There were 83 248 live births for the 9-year period; 71 389 non-Indigenous and 11 859 Indigenous births. There were 69 SIDS deaths (0.83 per 1000 live births). Overall, recording of demographic and death scene data was poor. Thirty-eight autopsies (55%) were performed by specialist pathologists. There were 22 (32%) non-Indigenous and 22 (32%) Indigenous SIDS deaths (25 ethnicity unknown), giving an estimated relative risk of 2.82 (95% CI 2, 4). Median age at death was 13.1 weeks (range 1-83 weeks) with 14% of deaths occurring in the neonatal period for both groups. Sleeping position was not recorded in 42% of cases and co-sleeping was not recorded in 27% of cases. Bed sharing was more common amongst Indigenous infants. Fifty-two per cent of SIDS cases occurred in the wet season and 48% in the dry season. CONCLUSIONS: Data recorded for SIDS deaths in north Queensland are poor, preventing specific conclusions concerning SIDS risk factors. However, SIDS rates may be up to three-fold higher in the Indigenous population. A uniform system of post-mortem and death scene data reporting is needed urgently.     

Selective screening of 10,000 high-risk Brazilian patients for the detection of inborn errors of metabolism

The number of diagnosed inborn errors of metabolism (IEM) is growing constantly due to the improvement and widespread availability of analytical techniques. In 1982, a laboratory for the detection of IEM was set up in Porto Alegre, Brazil, and became a national reference centre for the diagnosis of these disorders. Ten thousand patients with signs and symptoms suggestive of IEM were investigated in our laboratory from 1982 to 1995 using specific protocols which included tests for the detection of glucosaminoglycans (GAGS), amino acids, sugars, oligosaccharides, sialyloligosaccharides, organic acids, as well as various metabolites. The biochemical investigation was completed in 9,901 patients and an IEM was detected in 647 cases (6.5%). Groups of IEM of higher incidence in our sample were lysosomal storage disorders (59.8%) and aminoacidopathies (21.2%). The disorders most frequently diagnosed were classical phenylketonuria, GM1 gangliosidosis, mucopolysaccharidosis type I, mucopolysaccharidosis type VI and metachromatic leukodystrophy. Conclusion This study shows that the establishment of reference centres for the investigation of rare genetic diseases is a suitable approach to the study of IEM in developing countries such as Brazil. Received: 19 November 1996 / Accepted: 3 December 1996     

Overview of sudden infant death syndrome in Japan

In spite of rapid medical advancement in the care of infants and children, not only the general public but also many medical personnel have remained unaware of sudden infant death syndrome (SIDS) until very recently in Japan. In 1981, a research project team on SIDS financed by the Ministry of Health and Welfare was founded. Current incidence of SIDS is estimated to be about 0.5 per 1000 live births. The SIDS Family Association was organized in 1993 in Japan and began to publicize the social importance of SIDS and to support SIDS families by training befrienders. A series of articles on current achievements from SIDS research projects and from the SIDS Family Association are submitted to this issue. The present paper summarizes the status of SIDS in Japan by overviewing the activities of the research team and the SIDS Family Association.     

Couple distress after sudden infant or perinatal death: a 30-month follow up

OBJECTIVE: To examine, using a 30-month prospective study, patterns of anxiety, depression and alcohol use in couples following stillbirth, neonatal death or sudden infant death syndrome. METHODOLOGY: One hundred and thirty-eight bereaved and 156 non-bereaved couples completed standardized interviews at 2, 8, 15 and 30 months post-loss. RESULTS: At all interviews, bereaved couples were significantly more likely than non-bereaved couples to have at least one distressed partner. Rarely were both partners distressed in either group. For bereaved couples, 'mother only' distress declined from 21% to 10% during the study. 'Father only' distress ranged from 7% to 15%, peaking at 30 months. Bereaved mothers who were distressed at 2 months reported significantly lower marital satisfaction at 30 months. CONCLUSIONS: At the couple level, the experience of a baby's death is multifaceted. Gender differences are common and partners' needs may change over time. Early recognition of these differences may facilitate longer-term adjustment for both partners.     

Prevalence of congenital adrenal hyperplasia among sudden infant death in the Czech Republic and Austria

This study aimed to estimate the number of infants who died of unrecognized congenital adrenal hyperplasia (CAH) in Austria and the Czech Republic within the past 13 years, before the introduction of adequate neonatal screening. The study was based on retrospective analysis of neonatal screening cards of 242 infants who died suddenly between 7 days and 12 months of age and whose cause of death could not be identified. 17-hydroxyprogesterone (17-OHP) was measured by fluoroimmunoassay and positive samples were subsequently genotyped. Three infants out of 242 may have had unrecognized CAH due to CYP21 (steroid 21-hydroxylase) gene defect. Their newborn 17-OHP levels and CYP21 genotypes were 706 nmol/l and del/conv//del/conv, 53 nmol/l and I2//I2, and 811 nmol/l and I2//Gln318stop, respectively. CAH due to CYP21 defect can lead to sudden unexpected death without prior symptoms typical for the condition. Hence, newborn screening would have prevented these deaths had it been available. In addition, we have shown that the I2 point mutation that is expected to lead to simple virilizing form may lead to a fatal outcome.     

Sudden infant death syndrome in pediatric surgical cases and consequences for postoperative care

We encountered 5 cases of sudden infant death syndrome (SIDS) at the Pediatric Surgical Clinic of the University Children's Hospital of Munich from 1976 to 1985. This corresponded to 0.2 of the cases treated as inpatients during this 10-year period. Consequently, all infants requiring anesthesia and surgery during their first 6 months of life and who were premature, have had apneic spells or other respiratory problems, or have congenital heart disease are monitored for at least 4 days following surgery, even if they undergo operations that would otherwise be performed in the frame of 1-day surgery. No further case of SIDS was encountered since the introduction of this measure in 1985. Moreover, a former premature who was operated on for umbilical hernia and developed bradycardia postoperatively was saved by intensive care. Without monitoring, this child could well have been our 6th case of SIDS (near-miss event). Offprint requests to: T. A. Angerpointner