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Biomedical subjects

C Wren

Publications and source records attributed to C Wren.

At least 37 records · Page 2Linked to original sources
PubMed1999

Prevalence and clinical significance of cardiac murmurs in neonates.

AIM: To determine the prevalence and clinical significance of murmurs detected during routine neonatal examination. METHODS: In a two year prospective study, 7204 newborn babies underwent routine examination by senior house officers. All those with murmurs underwent echocardiographic examination. All babies presenting later in infancy were also identified, to ascertain the total prevalence of congenital heart disease in infancy. RESULTS: Murmurs were detected in 46 babies (0.6%) of whom 25 had a cardiac malformation. The most common diagnosis was a ventricular septal defect, although four babies had asymptomatic left heart outflow obstruction. A further 32 infants from the same birth cohort had a normal neonatal examination but were found to have a cardiac malformation before 12 months of age. CONCLUSIONS: The neonatal examination detects only 44% of cardiac malformations which present in infancy. If a murmur is heard there is a 54% chance of there being an underlying cardiac malformation. Parents and professionals should be aware that a normal neonatal examination does not preclude a clinically significant cardiac malformation. The detection of a murmur should prompt early referral to a paediatric cardiologist for diagnosis or appropriate reassurance.

Echocardiography↗
PubMed1999

Examination for cardiac malformations at six weeks of age.

AIM: To attempt to define the prevalence and significance of murmurs detected on routine clinical examination at six to eight weeks. METHODS: A retrospective review of the results of routine clinical examination of a cohort of 6 to 8 week old babies resident in Newcastle upon Tyne, was carried out in two 12 month periods. All cardiac defects diagnosed in infancy in the same cohort were ascertained. RESULTS: 7132 babies were eligible for routine examination; 83% of these were examined. Murmurs were heard in 47 of 5395 babies and in 11 of 25 referred for evaluation congenital heart disease was found. The six to eight week examination led to diagnosis of 11 of 35 cases (31%) of congenital heart disease in the study population. CONCLUSIONS: Nearly one baby in 100 had a murmur on routine examination at six to eight weeks. Nearly half of those with murmurs who were referred had a structural cardiovascular malformation.

Heart Defects, Congenital↗
PubMed1999

Presentation of congenital heart disease in infancy: implications for routine examination.

AIM: To investigate the performance of routine neonatal and 6 week examinations for detecting congenital heart disease. METHODS: A retrospective review of findings on clinical examination was conducted of a cohort of live born infants with congenital heart disease in one health region in 1987-94. RESULTS: Of 1590 babies with congenital heart disease, 523 (33%) presented before neonatal examination because of symptoms or non-cardiac abnormalities. 1061 underwent routine neonatal examination which was abnormal in 476 (45%), but only 170 were referred directly for diagnosis. Of 876 discharged with no diagnosis, 306 presented or died undiagnosed before 6 weeks. At 6 weeks 252 of 569 babies underwent a second routine examination which was abnormal in 164 (65%). CONCLUSIONS: Routine neonatal examination fails to detect more than half of babies with heart disease; examination at 6 weeks misses one third. A normal examination does not exclude heart disease. Babies with murmurs at neonatal or 6 week examinations should be referred for early paediatric cardiological evaluation which will result either in a definitive diagnosis of congenital heart disease or in authoritative reassurance of normal cardiac anatomy and function.

Down Syndrome↗
PubMed1998

Atrial fibrillation with neonatal pulmonary lymphangiectasia.

A female infant born at 28 weeks' gestation was found to have mild hydrops foetalis. Initial echocardiography showed a structurally normal heart. During the first week of life, episodic atrial tachycardia with 1:1 or 2:1 conduction was seen, requiring therapy with digoxin. The infant remained ventilator dependent, with a persistent, chylous pleural effusion which contained a preponderance of lymphocytes. Congenital pulmonary lymphangiectasia (CPL) was confirmed histologically. Worsening episodes of atrial tachycardia, including episodes of atrial fibrillation, were further investigated and a repeat echocardiogram revealed thickening of the entire right atrial wall. The cardiac findings of a thickened right atrial wall with the histological signs of myocarditis were thought to be the cause of paroxysms of atrial fibrillation, an extremely rare arrhythmia in the neonatal period. To the authors' knowledge there have been no previous reports of CPL in association with the cardiac abnormalities described herein.

Atrial Fibrillation↗
PubMed1998

A population study of chromosome 22q11 deletions in infancy.

AIMS: To determine the prevalence of submicroscopic deletions within chromosome band 22q11 in infants with significant heart disease and compare this with the prevalence of other chromosomal abnormalities causing significant heart disease. To determine a minimum prevalence of deletions within chromosome band 22q11 in infants in the general population. METHODS: Chromosome analysis was performed on samples from infants born in the former UK Northern Health Region in 1994 and 1995 who either had significant heart disease or who were suspected to have a chromosome band 22q11 deletion following referral to the Northern Genetics Service. Significant heart disease was defined as major structural malformation or cases where invasive investigation or intervention was required in infancy. RESULTS: Chromosome band 22q11 deletions were identified in nine infants in a population of 69,129 livebirths, giving a minimum prevalence of 13 per 100,000 (95% confidence interval 4.5 to 21.5). Six cases had significant heart disease, one of whom died before diagnosis. In the same population there were 53 cases of trisomy 21, 15 of whom had significant heart disease. CONCLUSION: The most common chromosomal cause of significant congenital heart disease remains trisomy 21, while the second most common chromosomal cause is deletion in chromosome band 22q11.

Abortion, Therapeutic↗
PubMed1998

Incessant tachycardias.

Incessant tachycardias are some of the rarer forms of normal QRS tachycardias. They are usually diagnosed in infancy or childhood and often present with heart failure secondary to left ventricular dysfunction. Permanent junctional reciprocating tachycardia is a rare type of orthodromic atrioventricular re-entry. Control with drugs is possible but best long-term results are achieved with radio-frequency ablation. Congenital His bundle tachycardia is an automatic arrhythmia characterized by ventriculo-atrial dissociation on the electrocardiogram. The risk of atrio-ventricular block with radiofrequency ablation is high and long-term drug treatment is often effective. Atrial ectopic tachycardia is also automatic and may originate in the left or right atrium. Drug suppression is possible but radiofrequency ablation offers the prospect of cure. All three arrhythmias are likely to persist long term. Drug treatment with class IC or class III drugs is most likely to be effective. Rate control or arrhythmia suppression are likely to lead to improvement or normalization of left ventricular function.

Anti-Arrhythmia Agents↗
PubMed1997

IsK and KvLQT1: mutation in either of the two subunits of the slow component of the delayed rectifier potassium channel can cause Jervell and Lange-Nielsen syndrome.

The Jervell and Lange-Nielsen syndrome (JLNS) comprises profound congenital sensorineural deafness associated with syncopal episodes. These are caused by ventricular arrhythmias secondary to abnormal repolarisation, manifested by a prolonged QT interval on the electrocardiogram. Recently, in families with JLNS, Neyroud et al. reported homozygosity for a single mutation in KVLQT1 , a gene which has previously been shown to be mutated in families with dominantly inherited isolated long QT syndrome [Neyroud et al . (1997) Nature Genet ., 15, 186-189]. We have analysed a group of families with JLNS and shown that the majority are consistent with mutation at this locus: five families of differing ethnic backgrounds were homozygous by descent for markers close to the KVLQT1 gene and a further three families from the same geographical region were shown to be homozygous for a common haplotype and to have the same homozygous mutation of the KVLQT1 gene. However, analysis of a single small consanguineous family excluded linkage to the KVLQT1 gene, establishing genetic heterogeneity in JLNS. The affected children in this family were homozygous by descent for markers on chromosome 21, in a region containing the gene IsK . This codes for a transmembrane protein known to associate with KVLQT1 to form the slow component of the delayed rectifier potassium channel. Sequencing of the affected boys showed a homozygous mutation, demonstrating that mutation in the IsK gene may be a rare cause of JLNS and that an indistinguishable phenotype can arise from mutations in either of the two interacting molecules.

Chromosomes, Human, Pair 21↗
PubMed1997

Strategies for antenatal detection of Down's syndrome.

AIM: To predict the effect of maternal serum screening and fetal echocardiography on the birth prevalence of Down's syndrome. METHODS: The outcome of all Down's syndrome pregnancies in the Northern Health Region between 1985 and 1991 was retrospectively ascertained. The number and outcome of all Down's syndrome pregnancies were used to define a theoretical population which would exist in the absence of screening. Published reports were used to predict the effects of screening strategies. RESULTS: Down's syndrome was identified in 412 pregnancies of which 315 (76%) resulted in live birth. A theoretical population with no antenatal screening would be expected to produce 31 stillbirths and 381 (92%) live births affected by Down's syndrome. In the same population a programme of maternal serum screening and fetal echocardiography would lead to 155 and 14 terminations, respectively, and when combined, would reduce affected live births to 229 (56%). CONCLUSIONS: Even if maternal serum screening and fetal echocardiography achieve their predicted potential, around half of all pregnancies affected by Down's syndrome will result in live born babies.

Adult↗
PubMed1995

Digoxin or flecainide for prophylaxis of supraventricular tachycardia in infants?

OBJECTIVES: This study compared the safety and efficacy of digoxin and flecainide in the prophylaxis of supraventricular tachycardia in infants. BACKGROUND: Recurrence of supraventricular tachycardia in infants is common. Digoxin is the conventional drug of first choice for prophylaxis, but its efficacy has not been tested in a controlled clinical trial, and there is no consensus on the drug of choice when digoxin is ineffective. METHODS: We reviewed retrospectively the records of all infants with supraventricular tachycardia due to atrioventricular (AV) reentry admitted to our hospital between January 1986 and December 1993. RESULTS: Thirty-nine infants presented with sustained AV reentrant tachycardia at age 1 to 330 days (median 12). Intravenous flecainide was required to maintain immediate control in six patients who were then treated with oral flecainide. The other 33 patients were treated with oral digoxin. There was no recurrence of tachycardia in 14 (42%) of the 33 patients (95% confidence interval [CI] 25% to 61%). In the other 19 patients (58%) (95% CI 39% to 75%), digoxin was replaced by oral flecainide because of multiple recurrence of tachycardia. Full control was achieved in all 19 of these patients (100%) (95% CI 82% to 100%) and in 5 of the 6 patients treated with both intravenous and oral flecainide. Thus, overall, flecainide was effective in 24 (96%) of 25 patients (95% CI 80% to 100%). CONCLUSIONS: Comparison with previous natural history studies suggests that digoxin is ineffective in the prophylaxis of supraventricular tachycardia. Oral flecainide was effective in a small number of infants, with no adverse effects (95% CI 0% to 12%), and may now be preferred as the primary prophylactic agent.

Anti-Arrhythmia Agents↗
PubMed1995

Antenatal diagnosis of congenital heart disease and Down's syndrome: the potential effect on the practice of paediatric cardiology.

OBJECTIVE: To predict the effect of antenatal ultrasound screening for congenital heart disease and maternal serum screening of Down's syndrome on the practice of paediatric cardiology and paediatric cardiac surgery. DESIGN: A retrospective and prospective ascertainment of all congenital heart disease diagnosed in infancy in 1985-1991. SETTING: One English health region. PATIENTS: All congenital heart disease diagnosed in infancy by echocardiography, cardiac catheterisation, surgery, or necropsy was classified as "complex", "significant", or "minor" and as "detectable" or "not detectable" on a routine antenatal ultrasound scan. RESULTS: 1347 infants had congenital heart disease which was "complex" in 13%, "significant" in 55%, and "minor" in 32%. 15% of cases were "detectable" on routine antenatal ultrasound. Assuming 20% detection and termination of 67% of affected pregnancies, liveborn congenital heart disease would be reduced by 2%, infant mortality from congenital heart disease by 5%, and paediatric cardiac surgical activity by 3%. Maternal screening for Down's syndrome, assuming 75% uptake, 60% detection, and termination of all affected pregnancies, would reduce liveborn cases of Down's syndrome by 45%, liveborn cases of congenital heart disease by 3.5%, and cardiac surgery by 2.6%. CONCLUSIONS: Screening for congenital heart disease using the four chamber view in routine obstetric examinations and maternal serum screening for Down's syndrome is likely to have only a small effect on the requirements for paediatric cardiology services and paediatric cardiac surgery.

Cardiac Surgical Procedures↗
PubMed1995

Differences in amiodarone, digoxin, flecainide and sotalol concentrations between antemortem serum and femoral postmortem blood.

1. The concentrations of amiodarone/desethylamiodarone, digoxin, flecainide and sotalol were measured in serum collected immediately prior to death and in postmortem blood collected from the femoral vein and artery of an 18-year-old male with congenital heart disease who developed a fatal arrhythmia. 2. The concentrations of all four drugs in the sample collected during life were consistent with the dosage given and in the range accepted for normal therapy. 3. There were no differences in amiodarone/desethylamiodarone, flecainide and sotalol concentrations in arterial or venous postmortem blood. 4. The concentrations of desethylamiodarone, digoxin, flecainide and sotalol but not amiodarone, were higher in postmortem blood than in antemortem serum. The flecainide concentration was significantly greater than the upper limit associated with toxicity in life. Without knowledge of the true concentration measured in life, this apparently high, toxic concentration would have suggested that death could have resulted from arrhythmogenic/proarrhythmic effects of the drug in excess. 5. These results further demonstrate the hazards in interpreting postmortem blood concentrations following suspected drug intoxication.

Adolescent↗
PubMed1994

Death in infancy from unrecognised congenital heart disease.

This study was undertaken to identify all congenital heart disease in infancy, including deaths before diagnosis, to provide a truer picture of the spectrum of congenital heart disease and to assess the 'treatability' of those dying before diagnosis. All births, infant deaths, and surviving babies with congenital heart disease in one health region in 1985-90 were identified and were classified as 'complex', 'significant', or 'minor'. Of the 1074 infants diagnosed in infancy, 185 died and 56 of these (30%) died undiagnosed. Severe non-cardiac malformations were present in 29 of the 56 while 27 were otherwise normal. Cardiovascular abnormalities in the latter group were complex in 13/27 and significant in 14/27. Identification of undiagnosed cardiovascular anomalies will improve epidemiological evaluation of congenital heart disease and, more importantly, earlier recognition of treatable abnormalities may reduce mortality.

Abnormalities, Multiple↗
PubMed1994

Presentation of obstructive left heart malformations in infancy.

This study documents the presentation of acutely life threatening congenital heart disease in infancy in order to assess the performance of screening examinations soon after birth and at 6 weeks of age. All cases of obstructive left heart malformations presenting in infancy in one health region from 1987-91 were analysed retrospectively. Altogether, 120 infants presented with either hypoplastic left heart syndrome, interruption of the aortic arch, coarctation of the aorta, or aortic valve stenosis. Twelve became symptomatic or died within 24 hours. Thirty four had an abnormal neonatal examination, eight of whom were referred. Six more became symptomatic before discharge. Ninety four babies went home, 51 developed heart failure before 6 weeks, and another seven died without diagnosis. Twenty five of 36 (69%) reaching 6 weeks without diagnosis had a second examination which was abnormal in 17. Two babies died undiagnosed after 6 weeks and the other 18 presented at up to 11 months of age. The neonatal and 6 week examinations perform poorly as screening tests for congenital heart disease. A normal neonatal examination does not exclude life threatening congenital heart disease.

Aorta, Thoracic↗