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Biomedical subjects

L Blieden

Publications and source records attributed to L Blieden.

At least 19 recordsLinked to original sources

Clinical presentations of mitochondrial cardiomyopathies.

UNLABELLED: To determine the clinical manifestations and interfamilial variability of patients diagnosed with a mitochondrial cardiomyopathy, we reviewed the charts of 14 patients with cardiomyopathy out of 59 patients with mitochondrial disorders who attended the mitochondrial disease clinic at Wolfson Medical Center from 1996 to 2001. All patients underwent a metabolic evaluation including blood lactate, pyruvate, carnitine, and amino acids and urine organic acids. Respiratory chain enzymes were assessed in 10 patients. The mitochondrial DNA (mtDNA) was assessed for mutations. The age at presentation ranged between 6 months and 24 years. Six of the patients died, 5 from heart failure. The cardiomyopathy was hypertrophic in 10 and dilated in 4. Conduction and rhythm abnormalities were present in 6. Eleven patients had family members with mitochondrial disorders. All the patients had additional involvement of one or more systems. Seven patients exhibited a deficiency of a respiratory chain enzyme in the muscle. The MELAS mtDNA point mutation (3243) was found in one patient. Blood lactic acid levels were increased in 5. Brain MRI abnormalities were observed in 4. CONCLUSIONS: Mitochondrial dysfunction frequently affects the heart and may cause both hypertrophic and dilated cardiomyopathy. The cardiomyopathy is usually a part of a multisystem involvement and may rarely be isolated. The course may be stable for many years, but rapid deterioration may occur. Understanding the biochemical and genetic features of these diseases will enable us to comprehend the clinical heterogeneity of these disorders.

Adolescent↗

The risk for congenital heart defects in offspring of individuals with congenital heart defects.

BACKGROUND: Congenital heart defects (CHDs) occur in approximately 1% of all live births. Although most CHDs are of unknown etiology, a family history of CHDs is a known risk factor, and offspring of individuals with CHDs are at a higher risk of having CHDs. The aim of this study was to investigate the relative risk for CHDs to offspring of individuals with CHDs. METHODS: The prevalence rates of CHDs in offspring of 203 individuals with CHDs and 282 individuals without CHDs were investigated. The study participants completed a questionnaire that included information on medical and reproductive history, lifestyle indicators, and family history of CHDs and other congenital malformations. The prevalence rates of CHDs in offspring were calculated. RESULTS: The prevalence of CHDs was 3.1% (18/575) in offspring of individuals with CHDs and 1.3% (8/589) in offspring of individuals without CHDs. The adjusted odds ratio for CHDs to offspring of parents with CHDs was 1.73 (95% confidence interval [95% CI] 0.89-2.44, p=0.02). The estimated relative risk for offspring to females with CHD was higher than for males [2.3 (95% CI 1.1-4.7, p=0.03) versus 1.31 (95% CI 0.48-4.30, p=0.66), respectively]. There was no suggestion of association between CHDs and maternal smoking, alcohol consumption, and use of medication during pregnancy. CONCLUSIONS: Offspring of parents with CHDs are at a higher risk for CHDs compared with the general population. Couples where one member is affected with CHD should receive pre-conceptional or pre-natal genetic counseling and should be informed about the magnitude of the potential risk of CHDs to the offspring.

Family Health↗

Inferior vena cava diameter: a useful method for estimation of fluid status in children on haemodialysis.

BACKGROUND: An accurate assessment of fluid status in haemodialysis patients presents a significant challenge especially in growing children. Clinical parameters of hydration are not always reliable, and invasive methods such as measurement of central venous pressure cannot be used routinely. We evaluated the usefulness of inferior vena cava diameter (IVCD) measured by echocardiography in the estimation of hydration in children on haemodialysis. METHODS: Fifteen haemodialysis patients (mean age 14 years) were evaluated. Clinical assessment included patients' symptoms, weight, blood pressure, heart rate, presence of oedema and vascular congestion, before and after dialysis session. Dry weight was assessed based on the above parameters. Fifty-two echocardiographic studies immediately prior and 30-60 min following dialysis were performed. The anteroposterior IVCD was measured 1.5 cm below the diaphragm in the hepatic segment in supine position during normal inspiration and expiration. IVCD was expressed per body surface area. RESULTS: Following haemodialysis mean IVCD (average of expiration and inspiration) decreased from 1.12+/-0.38 to 0.75+/-0.26 cm/m(2) (P<0.0001). Changes in IVCD were significantly correlated with alterations in body weight following dialysis (P<0.0001). The collapse index (per cent of change in IVCD in expiration vs inspiration) increased significantly after dialysis (P=0.035). IVCD clearly reflected alterations in fluid status. It did not vary significantly with changes in dry weight in a given patient. CONCLUSIONS: Our findings support the applicability of VCD measurement in the estimation of hydration status in paediatric haemodialysis patients. The combination of clinical parameters and measurement of IVCD may enable more accurate evaluation of hydration of children on haemodialysis.

Adolescent↗

[Transcatheter closure of atrial septal defect].

Isolated secundum atrial septal defect is one of the most common congenital heart defects. Surgical closure is the treatment of choice but is associated with a chest scar, some morbidity and a relatively long recovery and the use of cardiopulmonary bypass. Transcatheter closure of secundum atrial septal defect is therefore an attractive approach. 3 children, aged 5-10 years, underwent successful transcatheter closure of moderate to large central atrial septal defects with the Cardioseal device. The procedures were performed under x-ray and transesophageal echocardiographic guidance. Our initial experience, and that of others, indicates that transcatheter occlusion of secundum atrial septal defects is safe and effective and can be an appropriate alternative in approximately 60% of patients.

Cardiac Catheterization↗

Surgical management of ventricular septal defect with aortic valve prolapse: clinical considerations and results.

Aortic valve prolapse is found in over 5% of children with ventricular septal defect (VSD). Although this association occurs mostly with doubly committed subarterial VSDs, in this study the predominant type of VSD was perimembranous. In order to determine the need and timing for surgery and whether the anatomical features of septal defect may influence clinical management and outcome in this lesion, we reviewed our experience with 28 consecutive patients, operated on for VSD with prolapsed aortic valve cusp, with or without aortic regurgitation. Twenty-two patients had a perimembranous VSD and six had doubly committed VSD. Aortic regurgitation was trivial or absent in nine patients, mild in ten and moderate to severe in nine. Associated cardiac anomalies were present in 18 patients, all having perimembranous VSD, and included right ventricular outflow tract (RVOT) obstruction (n = 6), discrete subaortic membrane (n = 4) or both (n = 8). None of these patients had more than moderate aortic regurgitation. The patients underwent surgical closure of the septal defect between the ages of 1.5 and 34 years of age (median = 7). Sixteen patients having mild or trivial aortic regurgitation underwent closure of the VSD only, and 12 patients underwent VSD closure with aortic valvuloplasty. Valvuloplasty was required more often in doubly committed VSDs (66%) and in the perimembranous type without associated anomalies (100%), and significantly less often in the presence of RVOT obstruction, subaortic membrane or both (22%). At follow-up (up to 5 years, mean 18 months), the grade of aortic regurgitation was unchanged in 11 and decreased in 5 patients undergoing closure of the VSD only.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Successful pregnancy in a woman with cyanotic congenital heart disease after a palliative pulmonary-systemic shunt. A case report.

A 20-year-old woman with cyanotic congenital heart disease composed of corrected transposition of the great vessels, severe pulmonic stenosis, atresia of the left pulmonary artery and a large ventricular septal defect, had a successful pregnancy following a pulmonary-systemic shunt (Blalock-Taussig). The hemoglobin decreased from 21 to 16 g/dL following the operation. The antepartum course was complicated by intrauterine growth retardation and pregnancy-induced hypertension. A normal fetal nonstress test and biophysical profile permitted continuation of the pregnancy until 38 weeks' gestation, with delivery of a healthy infant.

Abnormalities, Multiple↗

A prospective evaluation of pediatric patients with syncope.

Fifty-eight children with syncope were evaluated prospectively to determine the characteristics of syncope in the pediatric age group and the yield of various diagnostic tests. The age at first syncope ranged from 0.5 to 15 years. Twenty-five children presented after a single episode and 33 after multiple episodes. Ten had a history of breath-holding spells. Nineteen had a family history of syncope. A diagnosis was established in 53 patients (91%): vasodepressor (31), cardioinhibitory (13), tussive (3), hyperventilation (2), and mixed syncope (4). In five patients (9%), the cause remained unknown. The diagnosis was established from the history in 45 cases, by a positive oculocardiac reflex in 11, and by the head-up tilt test in four. We conclude that the cause of most cases of pediatric syncope is vasodepressor or cardioinhibitory and can be diagnosed by good history-taking. Costly evaluations are rarely necessary.

Adolescent↗

Coronary risk factors in children of parents with premature coronary artery disease.

In order to assess the value of family history of premature coronary artery disease as a criterion for coronary risk factor screening, a group of 53 children with such a family history was selected. We determined various coronary risk factors in these children in comparison to 33 controls. Statistically significant differences were observed in apoprotein concentrations but not in concentrations of lipids, lipoproteins or glucose, or in blood pressure or body mass index. The ratio between apoprotein B and apoprotein AI was the best discriminator between the two groups. The predictive value of family history is more reliable for detecting abnormal apoprotein ratio than for detection of hypercholesterolemia. We conclude that if abnormal apoprotein levels during childhood are found to be a valued predictor of premature coronary artery disease, then family history of premature coronary artery disease can be used to select children for determination and assessment of their coronary risk.

Adolescent↗

Head-up tilt for the evaluation of syncope of unknown origin in children.

Fifteen patients aged 10 to 18 years with syncope of unknown origin, and 10 healthy control children aged 11 to 18 years, were evaluated by head-up tilt to 60 degrees for 60 minutes. Six patients (43%) reproduced symptoms of syncope during the examination. Four had a typical vasovagal reaction; two had marked hyperventilation. None of the children in the control group had syncope. The head-up tilt test offers a simple, noninvasive, high-yielding diagnostic tool for evaluation of syncope in children.

Adolescent↗

Placenta previa and congenital cardiac anomalies.

This study was designed to evaluate the association of placenta previa (PP) with cardiac anomalies in the fetus/neonate. The study group (n = 82 babies) was compared to a control group (n = 82) matched for maternal and gestational age. Five babies of the study group expired within 24 h of delivery, and postmortem examination was carried out in 4 of them. The living children of the control and study group (51 of the 77 babies) underwent complete cardiac workup including physical examination, ECG, chest X-ray and echocardiography. The incidence of congenital cardiac anomalies in the study group was significantly higher (Fisher exact test, p = 0.025). The obstetrician should refer the pregnant woman with PP for echocardiographic studies.

Adult↗

Recurrent preexcited reciprocating tachycardia, concealed ventricular preexcitation and conduction disturbances in the normal atrioventricular pathway in a newborn.

We describe a newborn infant with concealed ventricular preexcitation in sinus rhythm on the early ECGs, and who developed recurrent episodes of preexcited reciprocating tachycardia. Manifestation of the ventricular preexcitation and initiation of the tachycardias were dependent on the presence of severe conduction disturbances in the normal atrioventricular pathway, probably in the atrioventricular node.

Electrocardiography↗

Cerebrovascular accidents in infants and children with congenital cyanotic heart disease.

The red blood cell (RBC) counts and indices of 12 patients with congenital cyanotic heart diseases (CCHD) who had had cerebrovascular accidents (CVA) (study group) were compared with those of 41 infants and children with CCHD who had not had CVA (control group); the groups were matched for age and type of CCHD. The patients in the study group were found to have nonsignificantly lower hemoglobin levels and similar hematocrit levels, in comparison with the control group. On the other hand, significantly lower RBC indices were found among the patients of the study group in comparison with the control group. The arterial oxyhemoglobin concentration, studied in six patients of the study group, was not found to be significantly lower than that of the patients in the control group. Thus, we conclude that relative anemia with microcytosis is associated with the occurrence of CVA in children with CCHD.

Cerebrovascular Disorders↗

Intrauterine and postnatal atrial fibrillation in the Wolff-Parkinson-White syndrome.

A fetal tachyarrhythmia was discovered at the thirty-second week of gestation of a 22-year old woman. Fetal echocardiography revealed atrial fibrillation with rapid ventricular rate, without any other demonstrable cardiac abnormality. In spite of therapeutic maternal blood levels of digoxin, the fetal ventricular rate and cardiac size increased, which prompted us to perform cesarean section at the thirty-fourth week of gestation. A baby with a Wolff-Parkinson-White syndrome but no other cardiac anomaly was delivered. Recurrent episodes of nonsustained atrial fibrillation with conduction over the accessory pathway occurred in the first hours of life. The Wolff-Parkinson-White pattern was not present on subsequent ECG recordings. The use of echocardiography in the diagnosis and management of this rare fetal tachyarrhythmia is emphasized.

Adult↗

Steady state serum concentrations and renal clearance of digoxin in neonates, infants and children.

Steady state serum concentrations of digoxin were determined repeatedly in 34 infants with congenital heart disease. Simultaneous measurements of renal clearances of digoxin, creatinine and urea were obtained in 29 of the subjects. Serum digoxin concentrations were markedly higher in children under the age of 3 months than in those over this age, despite equal weight--adjusted 24 h doses. This finding was explained by a very rapid increase in renal digoxin clearance in the first 3 months--32 +/- 7 ml/min/1.73m2 at 1 week to 65.6 +/- 30 at 3 months. The subsequent increase in digoxin clearance was much slower, e. g. to 87.7 +/- 43 ml/min/1.73m2 at 12 months. Renal clearance of digoxin was equally well correlated with creatinine clearance (r = 0.87) as with urea clearance (r = 0.83), but it exceeded that of creatinine in all age groups. The findings indicate that both glomerular and tubular function is involved in the renal elimination of digoxin in young children, and that development of renal elimination of the drug parallels that of the maturation of renal function in the early months of life. The neonate and infant with congestive heart failure display impaired ability to eliminate digoxin. The impairment lessens rapidly with the development of renal function over the first 3 months of life. Diminished doses of digoxin should be advocated in this age group if therapeutic serum concentrations of the drug are to be maintained and toxicity avoided.

Aging↗

Steady state serum digoxin concentration in relation to digitalis toxicity in neonates and infants.

Steady state serum digoxin concentrations were determined in 34 neonates and infants receiving standard maintenance doses of the drug. Digitalis intoxication, diagnosed by ECG criteria, occurred in four of 13 patients with a serum concentration above 2 ng/ml and not in any of 21 subjects with a serum digoxin concentration below this level. This association was found to be significant. It seems that the concept of increased tolerance to digoxin hitherto ascribed to infants is not tenable and that the monitoring of serum digoxin concentration is essential to treatment in this age group.

Digitalis Glycosides↗