Effect of Magnesium on Ventricular Extrasystoles in Children.

Magnesium (Mg) is a crucial element for cardiovascular system and its deficiency results in a variety of cardiac arrhythmias. The aim of this study is to determine the effect of oral Mg supplementation on the frequency of ventricular extrasystoles (VES) in children. Magnesium supplementation was given to 42 children who had VES without structural heart disease. Clinical, electrocardiographic, and Holter monitoring studies were reviewed. The mean baseline 24 h VES burden on Holter monitoring was 10.26% ± 4.13% and it was decreased to 6.62% ± 3.88% after. There was no significant difference between the pre-treatment serum Mg levels and the decrease in the frequency of VES. In conclusion, oral Mg therapy was found to be effective at suppressing VES in children regardless of serum Mg levels. Large and randomized studies are needed to demonstrate the effect of magnesium on VES suppression.

Ventricular Extrasystole in Children: Single-Center Experience.

OBJECTIVE: Ventricular extrasystole is one of the most common rhythm disorders in children, and almost all of them are characterized by normal cardiac functions without structural cardiac abnormalities. The aim of this study was to assess the clinical course of ventricular extrasystole in children who did not have cardiac structural abnormalities. MATERIALS AND METHODS: This retrospective study analyzed 24-hour rhythm Holter recordings performed in our clinic in children. Patients diagnosed with isolated ventricular extrasystole in Holter records and without structural heart disease on echocardiography were included in the evaluation. RESULTS: A total of 20 160 Holter results were evaluated in the study, and 226 patients (male; 66%) met the criteria. The mean follow-up time was 8.7 ± 3.2 years. While 81.8% of the patients were asymptomatic, the most common symptom was palpitation and 5 patients had syncope. Of the patients, 72 (31.8%) received medical therapy. Beta-blockers were the most often pre- scribed medication. Cardiomyopathy did not develop in any of the patients during the follow- up period. A partial reduction in the frequency of ventricular extrasystole was observed in 42% of the patients, while complete recovery was observed in 22%. CONCLUSION: Ventricular extrasystole in children generally has a good prognosis; most of them are asymptomatic, and the rates of spontaneous regression over time are quite high, regard- less of the origin.

"Homozygous, and compound heterozygous mutation in 3 Turkish family with Jervell and Lange-Nielsen syndrome: case reports".

BACKGROUND: Jervell and Lange-Nielsen syndrome (JLNS) isa recessive model of long QT syndrome which might also be related to possible hearing loss. Although the syndrome has been demonstrated to be originated from homozygous or compound heterozygous mutations in either the KCNQ1 or KCNE1 genes, additional mutations in other genetic loci should be considered, particularly in malignant course patients. CASE PRESENTATIONS: Three patients were admitted into hospital due to recurrent seizures/syncope, intrauterine and postnatal bradycardia respectively; moreover all three patients had congenital sensorineural hearing-loss. Their electrocardiograms showed markedly prolonged QT interval. Implantable defibrillator was implanted and left cardiac sympathetic denervation was performed due to the progressive disease in case 1. She had countless ventricular fibrillation and appropriate shock while using an implantable defibrillator. The DNA sequencing analysis of the KCNQ1 gene disclosed a homozygous c.728G > A (p.Arg243His) missense mutation in case1. Further targeted next generation sequencing of cardiac panel comprising 68 gene revealed a heterozygous c.1346 T > G (p.Ile449Arg) variant in RYR2 gene and a heterozygous c.809G > A (p.Cys270Tyr) variant in NKX2-5 gene in the same patient. Additional gene alterations in RYR2 and NKX2-5 genes were thought to be responsible for progressive and malignant course of the disease. As a result of DNA sequencing analysis of KCNQ1 and KCNE1 genes, a compound heterozygosity for two mutations had been detected in KCNQ1 gene in case 2: a maternally derived c.477 + 1G > A splice site mutation and a paternally derived c.520C > T (p.Arg174Cys) missense mutation. Sanger sequencing of KCNQ1 and KCNE1 genes displayed a homozygous c.1097G > A (p.Arg366Gln) mutation in KCNQ1 gene in case 3. ß-blocker therapy was initiated to all the index subjects. CONCLUSIONS: Three families of JLNS who presented with long QT and deafness and who carry homozygous, or compound heterozygous mutation in KCNQ1 gene were presented in this report. It was emphasized that broad targeted cardiac panels may be useful to predict the outcome especially in patients with unexplained phenotype-genotype correlation. Clinical presentations and molecular findings will be discussed further to clarify the phenotype genotype associations.

Carvedilol therapy in pediatric patients with dilated cardiomyopathy.

Carvedilol reduces mortality and hospitalization in adults with congestive heart failure. Limited information is available about its use in children. The objective of this study was to determine the dosing, efficacy and side effects of carvedilol for the management of dilated cardiomyopathy in children. Sixteen children with idiopathic dilated cardiomyopathy, aged 7 months to 138 months and with an ejection fraction less than 40%, were treated with carvedilol. The average initial dose was 0.1 mg/kg/day and it was uptitrated to 0.4 mg/kg/day. After six months on carvedilol, there were improvements in clinical scoring system from an average of 2.94 to 2.50 (p<0.05), in mean fractional shortening from 17.2 +/- 6.1% to 22.7 +/- 5.1% (p<0.05), and in ejection fraction from 35.2 +/- 6.8% to 43.1 +/- 11.2% (p<0.05). No side effect was observed during the study period. Two patients died due to serious infection. Carvedilol in addition to standard therapy for dilated cardiomyopathy in children improves cardiac function and symptoms. It is well tolerated, with minimal adverse effects, but close monitoring is necessary.

Suspicion, diagnosis, and successful surgical treatment of anomalous origin of the anterior descending coronary artery from the pulmonary trunk.

Anomalous origin of the anterior descending coronary artery from the pulmonary trunk is very rare. We suspected such anomalous origin in a boy aged 2.5 years owing to the echocardiographic demonstration of mitral regurgitation and abnormal diastolic flow in the ventricular septum. The diagnosis was confirmed by angiography. The anomalous artery was successfully reimplanted into the aorta.

The effect of age and gender on the electrocardiogram in children.

Our aim was to determine, using a computer program for measurement and analysis, the effects, if any, of age and gender on the electrocardiographic measurements in a large cohort of Turkish children. We analyzed standard simultaneous 12-lead electrocardiograms from 2241 healthy Turkish children, aged from 1 day to 16 years, to calculate limits of normality of a variety of electrocardiographic measurements for 12 age groups. Clinically significant differences were shown to exist, and the results compared with previously established normal limits. Differences were demonstrated for gender in measurements of both amplitude and duration, particularly in the adolescent period. We have provided tables and figures showing age and gender-dependent means and upper limits of normal electrocardiographic parameters for the important leads.

The prospective follow-up of the natural course of interatrial communications diagnosed in 847 newborns.

AIMS: The aim of this study was to evaluate the prevalance of interatrial communications (IACs) and IAC types in a large series of newborns, to establish the incidence of spontaneous closure of IACs, to determine the relationship between spontaneous closure and the size and type of IACs, and to investigate the incidence of mitral valve prolapse (MVP) and atrial arrhythmia in newborn infants with atrial septal aneurysm (ASA). METHODS AND RESULTS: Between 2000 and 2001, a total of 1100 asymptomatic and term newborns were evaluated. Those who had congenital heart diseases and failed to attend the follow-up visits were excluded from the study. The remaining 847 newborns were followed until the closure time or in those where closure did not occur, for a maximum time of 45 months (mean 25 +/- 3 months, range 1-45 months). The mean age at diagnosis was 1.7 +/- 1.4 days (range 1-7 days). According to echocardiographic evaluation, cases were classified into four groups based on the initial size of IAC and into three groups based on the type of IAC. At the end of the 45th month IACs were closed spontaneously in 98.6% of the cases. There was significant relationship between the diameter of IAC and the timing of the closure (P < 0.01). The closure time in the cases with ASA was significantly longer than the cases with valve-like opening and multiple fenestration (P < 0.01). In female newborns, the defects remained open for a significantly longer period than male newborns (P = 0.0397). There was no significant relationship between ASA and atrial arrhythmias (P = 0.294). None of the newborns had MVP. CONCLUSION: The cases with IACs < 3 mm do not need follow-up. However, the cases with IACs > 3 mm do need to be followed until the defect closes completely. Those with ASA should be followed-up regularly, because these defects can remain open. Spontaneous closure occurs significantly earlier in cases with valve-like opening and multiple fenestration.

Bilateral multiple pulmonary arteriovenous fistulas and duplicated renal collecting system in a child with Noonan's syndrome.

Noonan's syndrome involves the association of multiple congenital abnormalities, with a variety of cardiac defects. We describe here the association of Noonan's syndrome with multiple pulmonary arteriovenous fistulas and bilateral duplicated renal collecting systems. To the best of our knowledge, this is the first reported case of an association of the Noonan phenotype with pulmonary arteriovenous fistulas.

Dilated cardiomyopathy in childhood: prognostic features and outcome.

The natural history of dilated cardiomyopathy in children is difficult to predict due to the heterogeneous character of the disease. The outcome in infants and children is highly variable from complete recovery to death. In this study, 40 children diagnosed with dilated cardiomyopathy between 1995 and 2004 in our paediatric cardiology unit were reviewed with respect to clinical course and outcome, retrospectively. The medical history of these patients with dilated cardiomyopathy was reviewed to determine age, gender, family history, preceding viral illness, duration of symptoms before the diagnosis, symptoms and signs at presentation, treatment and outcome. The diagnosis was made on the basis of cardiomegaly and evidence of poor left ventricular function by echocardiography. Median age at diagnosis was 14 months, ranging from 2 months to 8 years. At presentation, 28 patients (70%) were under and twelve (30%) were above the age of two years. Twenty-eight (70%) patients had signs of congestive heart failure. Mean duration of follow-up was 40 +/- 24 months (ranging from 6 months to 9 years), 21 patients (52.5%) recovered, 17 patients (42.5%) had residual disease and two (5%) died. The cause of death in both patients was progressive cardiac failure. Sixteen of 28 patients (57%) who were below the age of two years and five of 12 patients (42%) who were above the age of two years at presentation recovered. The rate of recovery was significantly different between the two age groups (p < 0.05). Seventeen of 21 (81%) patients with a history of recent viral illness at presentation recovered. The mean duration of the disease among those who recovered was 11 +/- 8.3 months. Five of 19 (26%) patients without recent viral illness recovered. The mean duration of the disease in this group was 22 +/- 12 months. There was a significant difference between the two groups with respect to recovery and recovery time (p < 0.05). During the first 6 months after diagnosis, there was a significant difference between the patients who recovered and the patients who had residual disease with respect to improvement in the left ventricular FS (22 +/- 3.5%, 15.2 +/- 2.8%, respectively) (p < 0.05). In conclusion, in this study, the rate of recovery and survival is higher than in previous studies. A good outcome is related to age at presentation (< or = two years old), a history of viral disease within three months of presentation and improvement in ventricular function during the first 6 months after diagnosis. Intractable heart failure has an adverse effect on the outcome.

Case of tetralogy of Fallot associated with hypoplasia of the right pulmonary artery. The right internal mammary artery as an aortopulmonary collateral artery in tetralogy of Fallot.

A three-month-old girl was referred to pediatric cardiology unit for evaluation of mild cyanosis and murmur. Chest roentgenogram revealed a boot-shaped heart. Echocardiography demonstrated subaortic ventricular septal defect, aortic override and infundibular stenosis. Then, the patient diagnosed as tetralogy of Fallot (TOF). Cardiac catheterization and angiocardiography revealed infundibular narrowing, hypoplasia of the right pulmonary artery and the enlarged right internal mammary artery originating from the right subclavian artery supplied blood flow into the right lung. The patient was performed complete repair. Post-operative period was uneventful. This is the first report presented about a case which pulmonary blood flow is provided by the enlarged right internal mammary artery in TOF associated with hypoplasia of the right pulmonary artery.

Spontaneous resolution of ventricular tachycardia with right bundle branch block morphology: a case report.

Ventricular tachycardia is rare in children. In the absence of structural heart disease, ventricular tachycardia is known as idiopathic ventricular tachycardia and carries a good prognosis. We report a 14-month-old male child with right bundle branch block incessant ventricular tachycardia without structural heart disease. In this patient ventricular tachycardia was controlled by amiodarone and disappeared during follow-up. We want to stress the benign nature of this tachycardia if the previous treatment protocol had been appropriate.

Dual chamber cardiac pacing in children: Single chamber pacing dual chamber sensing cardiac pacemaker or dual chamber pacing and sensing cardiac pacemaker?

BACKGROUND: Dual chamber pacemakers (single chamber pacing dual chamber sensing cardiac pacemaker (VDD) and dual chamber pacing and sensing cardiac pacemaker (DDD)) are being used frequently in children and adolescents. The aim of this study was to verify the safety and performance of the VDD and DDD pacing systems, and to evaluate the differences between two pacing modes with regard to atrial sensing and tracking functions. METHODS: In this study, we evaluated 14 patients with VDD pacing and 15 patients with DDD pacing between 1994 and 2000. In the patient group with VDD pacing, all had congenital or acquired atrioventricular (AV) block. In the patient group with DDD pacing, 11 had congenital or acquired AV block, three had sinus node dysfunction with AV conduction disturbance and one had idiopathic hypertrophic subaortic stenosis. Twenty-eight devices were implanted in the subpectoral area using the transvenous route. After implantation the atrial tracking capabilities of the pacing systems were analyzed by telemetry, Holter monitoring, and treadmill exercise testing. RESULTS: The mean age of patients in the VDD pacing group was younger. The percentage of congenital heart disease was higher in the DDD pacing group. There was no significant difference regarding fluoroscopy time during implantation and follow-up time between the two groups. During implantation, in the VDD pacing group the mean sensed atrial signal was 3.1 +/- 1.3 mV and this decreased to 1.37 +/- 0.68 mV (P < 0.05) during follow-up. This pattern was also observed in DDD group (3 +/- 2 mV vs 1.9 +/- 1.5 mV, P < 0.05). Although the P wave measurement at implantation did not differ between the two groups, it was significantly higher in the DDD pacing group at the last control. Three patients with VDD pacing were reprogrammed to VVI or single chamber pacing and sensing, rate adaptive cardiac pacemaker because of complete loss of AV synchrony. There was no atrial sensing problem in the DDD pacing group. During the follow-up, one patient with VDD pacing developed diaphragmatic stimulation and required lead revision. In one patient with DDD pacing, venous thrombosis occurred in the right subclavian vein and was treated with thrombolytic therapy. During treadmill exercise testing, in one patient with VDD and one patient with DDD pacing temporary failure of atrial sensing occurred. At 24 h Holter monitoring, intermittent loss of atrial sensing was documented in two patients with VDD pacing. CONCLUSIONS: Dual chamber pacing in children with DDD or VDD pacemakers is a suitable method for bradycardia treatment. Atrial sensing problems may occur in VDD pacemakers. Therefore, DDD pacing mode should be preferred whenever suitable for the patient to maintain the AV synchrony.