Evaluation of Tissue Doppler Echocardiographic Imaging findings in children with pulmonary hypertension.

Akin A, Alehan D, Aykan HH, Özkutlu S, Özer S, Karagöz T. Evaluation of Tissue Doppler Echocardiographic Imaging findings in children with pulmonary hypertension. Turk J Pediatr 2017; 59: 244-253. Tissue Doppler Imaging has become an important prognostic marker that can be used in follow-up and determination of the prognosis in pulmonary hypertension patients. We compared the Tissue Doppler imaging parameters of 34 patients with pulmonary hypertension and 43 healthy controls. In addition, Brain-Natriuretic Peptide levels, pulmonary artery systolic pressures measured with echocardiography, 6-minute walking tests and New York Heart Association functional classification were compared. Among patients with Eisenmenger syndrome and idiopathic pulmonary hypertension, Tissue Doppler imaging parameters were mostly similar. In patients with New York Heart Association functional class 3, mitral septal annulus E/Ea (p=0.050) and mitral lateral annulus myocardial performance index (p=0.009) were higher than class 2 patients. In patients with higher Brain Natriuretic Peptide level, mitral lateral annulus and tricuspid septal annulus Ea/Aa values were lower (p=0.046 and < 0.001 respectively); tricuspid septal annulus E/Ea and interventricular septum myocardial performance index values were higher than in patients with normal Brain-Natriuretic Peptide level (p=0.006). In conclusion tissue Doppler imaging findings were significantly impaired in children with pulmonary hypertension compared to the control group. Findings were similar in patients with idiopathic pulmonary hypertension and Eisenmenger syndrome. Mitral lateral annulus myocardial performance index value may have a prognostic importance due its significant association with poor functional class. Due to the significant associations between mitral lateral annulus, tricuspid septal annulus Ea/Aa, tricuspid septal annulus Ea and E/Aa, interventricular septum-myocardial performance index values and brain natriuretic peptide levels, these parameters may be used in evaluating response to therapy.

Midterm Results of Implantable Cardioverter Defibrillators in Children and Young Adults from a Single Center in Turkey.

BACKGROUND: Despite concerns about complications with the implantable cardioverter defibrillator (ICD), it is effective for the prevention of sudden cardiac death (SCD). We aimed to analyze our midterm experience with ICD in children and young adults. METHODS: This retrospective study included patients who were implanted with an ICD between 2001 and 2014. Demographic characteristics, clinical information, shock features, and complications for all patients with ICD were analyzed. The study population was divided into two groups: early-era patients implanted before 2008, and late-era patients implanted after 2008. RESULTS: Sixty-nine patients (median age: 12 years, median follow-up: 52 months) were implanted with an ICD. Diagnostic categories were channelopathy (56.6%), cardiomyopathy (36.2%), congenital heart disease (5.8%), and other (1.4%). We performed implantation for primary prevention in 66.6% (39.3% in early-era patients and 85.4% in late-era patients). Thirty-one (44.9%) received 139 appropriate shocks (66% of total shocks) while 14 (20.2%) received 71 inappropriate shocks. However, there was no statistically significant difference in the use of appropriate shocks in the primary (66.7%) versus the secondary (72.2%) prevention groups. The incidence of appropriate and inappropriate shock was 66.7% and 33.3% in the primary prevention group, and 72.2% and 27.8% in the secondary prevention group, respectively. Two patients died, although only one death was the result of a lead problem. CONCLUSIONS: Although lead integrity problems, inappropriate shocks, and infections are significant issues, ICD therapy appears to be a safe, effective, and necessary option for the prevention of SCD in both children and young adults.

The Impact of Rapid Left Ventricular Pacing during Pediatric Aortic Valvuloplasty on Postprocedural Aortic Insufficiency.

OBJECTIVE: This study aims to determine efficacy and safety of rapid left ventricular pacing (RLVP) during balloon aortic valvuloplasty and effect on development of postprocedural aortic insufficiency (AI) in children. DESIGN: This is a retrospective comparison of 56 children (mean age 18.3 month; 1 day-15 years of age) who underwent valvuloplasty by using RLVP with standard method (without pacing) during same time period (74 children; mean age 12.6 month; 1 day-18 years of age). RESULTS: The systolic valvular gradient decreased from a mean 67 ± 20.4 mm Hg (26-120 mm Hg) before the procedure to a mean 27.6 ± 17.8 mm Hg (0-120 mm Hg) after the procedure. Procedure failed in two of the patients (3.6%) who received the RLVP; only two patients developed severe AI. Among those patients who underwent the standard method procedure failed in 6 patients (8.3%), whereas severe AI was seen in 15 (20.2%). RLVP decreased the incidence of postprocedure severe AI significantly (P < .01) but it had no effect on the gradient reduction of the procedure (P > .05). RLVP did not change the procedure duration, but decreased the duration of fluoroscopy significantly (P < .01). CONCLUSION: RLVP can be used effectively and safely for pacing during balloon aortic valvuloplasty procedures in all age groups; it decreases procedural failure rate, eases the procedure and prevents the development of AI through the stabilization of the balloon.

Subcutaneous defibrillator implantation in pediatric patients.

OBJECTIVE: Although sudden cardiac death is rare in children, an intracardiac defibrillator system is indicated in children with various types of cardiomyopathy, primary electrical diseases, and after surgical repair of congenital heart defects. The use of transvenous defibrillator lead systems is limited in pediatric patients because of a small body size and/or limited vascular access. Subcutaneous array leads combined with an abdominally placed generator can enable implantation. METHOD: This is a retrospective study of 13 patients who underwent subcutaneous defibrillator implantation between September 2010 and March 2015. The subcutaneous system was preferred because patients were not amenable to transvenous lead placement. RESULTS: The median patient age was 4.1 years, and the median patient weight was 12.1 kg. Diagnoses of patients were long-QT syndrome in 6, aborted cardiac arrest with left ventricular non-compaction in 3, hypertrophic cardiomyopathy with sustained ventricular tachycardia in 3, and arrythmogenic right ventricular cardiomyopathy in 1. Revision of the subcutaneous lead was required in 5 patients 2-26 months after the implantation. Appropriate shocks were observed in three patients. Inappropriate shock and lead fractures were observed in one patient during the follow-up period. The failure of therapy was observed in one patient. There were no perioperative complications and no early or late deaths. CONCLUSION: Subcutaneous defibrillator systems are safe and effective in pediatric patients when the transvenous method is risky and contraindicated. Because the high growth rate in this population leads to lead failures, a close follow-up of this population is essential.

Is transesophageal electrophysiologic study valuable in children with successful radiofrequency ablation of supraventricular tachycardia on follow-up for recurrence?

OBJECTIVE: The aim of this study was to evaluate the efficacy of transesophageal electrophysiologic study (TEEPS) for the determination of supraventricular tachycardia (SVT) recurrences in symptomatic and asymptomatic children after successful radiofrequency ablation (RFA) for SVT. METHODS: A total of 66 patients who underwent TEEPS after successful RFA were included. The demographic features, symptoms of the patients, and the characteristics of the recurrences induced by TEEPS were evaluated. The arrhythmia types induced during RFA were compared with those induced by TEEPS in terms of the compatibility of the diagnosis. RESULTS: Forty-two (63.6%) girls and 24 (36.4%) boys with a mean age of 11.8±3.4 years were followed-up for 44.1±15.7 months. The average time between RFA and TEEPS was 5.2±5.9 months. The diagnoses during RFA were atrioventricular nodal reentrant tachycardia (AVNRT) in 47 of 66 patients, atrioventricular reentrant tachycardia (AVRT) in 18 of 66 patients, and ectopic atrial tachycardia in 1 of 66 patients. SVT was induced by TEEPS in 2 of 25 symptomatic and 5 of 41 asymptomatic patients. The SVT inducibility rate was 5.5% (1/18) and 12.7% (6/47) in patients with AVRT and AVNRT, respectively. In addition, 85.7% (6/7) of all recurrences occurred within 3.5 months. The recurrences as AVNRT in 2 of 25 symptomatic patients occurred in the first month after RFA. AVNRT in 4 of 41 and AVRT in 1 of 41 asymptomatic patients were induced within 3.5 months and 15 months, respectively. CONCLUSION: TEEPS seems to be a valuable screening and diagnostic method for the determination of recurrence in symptomatic and asymptomatic children who underwent successful RFA.

Interventional cardiac catheterization in infants weighing less than 2500 g.

The aim of our study was to share our clinical experience regarding cases of interventional cardiac catheterization in low-weight infants. We retrospectively reviewed all interventional catheterizations performed in infants weighing 2500 g or less between March 2001 and October 2012. Twenty patients were included in the study. The procedures included balloon atrial septostomy in 8 patients, balloon pulmonary valvuloplasty in 7 patients, balloon aortic valvuloplasty in 3 patients and balloon angioplasty for coarctation in 2 patients. The mean age at catheterization was 11.9 ± 9.6 days (range, 1 to 31 days) and the mean weight, 2038 ± 480 g (range, 1100 to 2500 g). The mean procedure time was 80.3 ± 32 minutes, and the mean fluoroscopy time was 17.5 ± 12 minutes. Only two patients had no benefit from the intervention. One patient died at day 4 after catheterization, due to sepsis. Complications occurred in 3 patients: one patient developed atrial flutter and respiratory arrest, one patient developed apnea episodes, and one patient developed anemia that required transfusion. In conclusion, although studies investigating complications related to invasive cardiac catheterization in infants weighing less than 2500 g have reported increased complication rates, such complications were less likely to result in permanent sequelae. We did not observe significant complications related to the procedure; therefore, we would like to suggest that invasive cardiac catheterization can appropriately be performed in low-weight infants.

Comparison of Transesophageal and Intracardiac Electrophysiologic Studies for the Diagnosis of Childhood Supraventricular Tachycardias.

In this study, we aimed to compare the results of transesophageal electrophysiologic studies (TEEPS) and intracardiac electrophysiologic studies (IEPS) in a cohort of pediatric patients with SVTs. The medical records of children aged between 0 and 18 years who underwent TEEPS between January 2007 and June 2012 were systematically reviewed, and those without pre-excitation and who underwent subsequent IEPS were identified. Post-procedural diagnoses were compared for compatibility. A total of 162 patients were included in the study with a mean age at diagnosis 11.6 ± 3.6 years. Tachycardia was induced in 152 patients by TEEPS and in 154 patients by IEPS. Overall, in 147 patients, tachycardia was induced by both TEEPS and IEPS. Diagnoses were compatible in 135 out of 147 patients (91.8 %). Nine out of the 12 patients with discrepant results were diagnosed with atrioventricular-reentrant tachycardia (AVRT) and three with atrioventricular nodal reentrant tachycardia (AVNRT) after TEEPS. Following IEPS, TEEPS diagnosis of AVRT was revised to typical AVNRT in 5 patients and atypical AVNRT in 4 patients. Two of the 3 patients who were diagnosed as having AVNRT following TEEPS were confirmed to have atrial tachycardia after IEPS, while the other patient was diagnosed with AVRT. Tachycardia terminated spontaneously in 3 patients, while overdrive pacing was attempted to terminate the tachycardia in 149 patients, with a success rate of 93.2 % (139/149). The diagnostic compatibility between TEEPS and IEPS is quite high. A diagnostic discrepancy mostly occurs in patients diagnosed with AVRT by TEEPS, and the possibility of atypical AVNRT should be considered in patients with a VA ≥70 ms to avoid such discrepancies.

Clinical and electrophysiological evaluation of pediatric Wolff-Parkinson-White patients.

OBJECTIVE: Wolff-Parkinson-White (WPW) syndrome presents with paroxysmal supraventricular tachycardia and is characterized by electrocardiographic (ECG) findings of a short PR interval and a delta wave. The objective of this study was to evaluate the electrophysiological properties of children with WPW syndrome and to develop an algorithm for the management of these patients with limited access to electrophysiological study. METHODS: A retrospective review of all pediatric patients who underwent electrophysiological evaluation for WPW syndrome was performed. RESULTS: One hundred nine patients underwent electrophysiological evaluation at a single tertiary center between 1997 and 2011. The median age of the patients was 11 years (0.1-18). Of the 109 patients, 82 presented with tachycardia (median age 11 (0.1-18) years), and 14 presented with syncope (median age 12 (6-16) years); 13 were asymptomatic (median age 10 (2-13) years). Induced AF degenerated to ventricular fibrillation (VF) in 2 patients. Of the 2 patients with VF, 1 was asymptomatic and the other had syncope; the accessory pathway effective refractory period was ≤180 ms in both. An intracardiac electrophysiological study was performed in 92 patients, and ablation was not attempted for risk of atrioventricular block in 8 (8.6%). The success and recurrence rate of ablation were 90.5% and 23.8% respectively. CONCLUSION: The induction of VF in 2 of 109 patients in our study suggests that the prognosis of WPW in children is not as benign as once thought. All patients with a WPW pattern on the ECG should be assessed electrophysiologically and risk-stratified. Ablation of patients with risk factors can prevent sudden death in this population.

Serum Bcl-2 values in children with pulmonary hypertension.

In this study, we aimed to assess levels of serum B cell lymphoma 2 (sBcl-2) in children, which has been implicated in the etiopathogenesis of pulmonary hypertension (PH), as well its association with tissue Doppler echocardiographic imaging (TDI) data and parameters used in the follow-up of PH. The sBcl-2 level was assessed in 35 children with PH (24 had eisenmenger syndrome, and 11 had idiopathic PH) and in 38 healthy children as controls. TDI was performed on 25 patients whose cardiac anatomy allowed the test. The respective sBcl-2 values in patients and controls were 35.69 ± 18.83 and 2.66 ± 7.95 ng/ml (p < 0.001). The sBcl-2 levels were significantly greater in the New York Heart Association (NYHA) functional class 3 patients than those in the NYHA class 2 patients (p = 0.033). The sBcl-2 value in patients who walked <475 m in the 6-min walk distance (6MWD) test was significantly greater than in those who walked ≥475 m (p = 0.038). The sBcl-2 level showed a negative correlation with ejection time measured at the septal anulus (p = 0.026) and a positive correlation with interventricular septum-Tei (p = 0.018). The results of this study showed for the first time that there is an increase in the levels of sBcl-2 as an inflammatory marker and that the sBcl-2 levels are associated with prognostic parameters in children with PH. Because sBcl-2 levels were greater in patients who walked <475 meters during the 6MWD test, we suggest 475 ms as the cut-off value for the 6MWD test to differentiate between a good and a bad prognosis.

Results of radiofrequency ablation in children with tachycardia-induced cardiomyopathy.

OBJECTIVE: Tachycardia-induced cardiomyopathy (TIC) is a rare but potentially curable cause of dilated cardiomyopathy. Data on radiofrequency ablation (RFA) for TIC is limited. The aim of this study is to present our experience with RFA in children with TIC, retrospectively. METHODS: The medical records of patients with TIC and those underwent RFA between 2000-2011 were systematically reviewed. Demographics and echocardiographic features were recorded. Tachycardia-induced cardiomyopathy is defined as dilatation of the heart chambers or heart failure with chronic or very frequent cardiac arrhythmia. Diagnosis was confirmed with normalization of functions after sinus rhythm has been achieved. RESULTS: A total of 12 patients with a mean age of 6.3±4.1 years (in utero-11.5 years) at diagnosis were enrolled in the study consisting of 7 patients with permanent junctional reciprocating tachycardia and 5 patients with focal atrial tachycardia. The mean pre-RFA left ventricular end-diastolic diameter and left ventricular ejection fraction (LVEF) values were 49.1±9.6 mm (32-66) and 40.8±13.4% (23-57%), respectively. One month after RFA, the mean LVEF value was 62±4.9% (52-69), with only 2 out of 12 patients' LVEF values were still lower than 58%. Tachycardia recurrence was observed in 4 patients, 3 of which had successful repeated RFA procedure. Overall, cure for arrhythmia was achieved in 11 patients (92%), while reversal of heart failure achieved in all patients. In 1 patient permanent complete AV block was developed after the procedure. CONCLUSION: Treatment of tachycardia with RFA, particularly in patients with arrhythmia refractory to medical therapy, is a feasible and effective treatment option regardless of age.

Sensitivity of transesophageal electrophysiologic study in children with supraventricular tachycardia on electrocardiography.

INTRODUCTION: The aim of this study was to evaluate the inducibility of tachycardia by transesophageal electrophysiologic study (TEEPS) in patients with documented supraventricular tachycardia (SVT) on electrocardiography and to investigate the accuracy of TEEPS records by comparing with intracardiac electrophysiologic study (IEPS). MATERIAL AND METHODS: The TEEPS records of patients having documented electrocardiography during SVT were reviewed. The results of TEEPS in 43 of 85 patients were compared with results of IEPS for compatibility of diagnosis. RESULTS: A total 85 patients, 46 male and 39 female, mean weight 35.1 kg (36-87), aged 1 month-17 years, were included. Tachycardia was induced by TEEPS in 79 of 85 patients with documented electrocardiography (sensitivity 92.9%). IEPS for diagnosis or ablation was conducted in 40 patients having inducible tachycardia and three of six who had no inducible tachycardia by TEEPS. Tachycardia was induced by IEPS in 39 of 40 (97.5%) patients who had inducible tachycardia and two of three who had no inducible tachycardia by TEEPS. Mechanisms of tachycardias were similar in 97.5% of patients (37/39) who had inducible tachycardia in TEEPS and IEPS. One of the patients with atrioventricular reentry tachycardia by TEEPS was diagnosed as atrioventricular nodal reentry tachycardia (AVNRT) and the other one was diagnosed as atypical AVNRT and atrial tachycardia by IEPS. CONCLUSION: The rates of inducibility and mechanisms of tachycardias by TEEPS in children having documented SVT were similar with those obtained from IEPS.

Jervell and Lange-Nielsen syndrome with homozygous missense mutation of the KCNQ1 gene.

Jervell and Lange-Nielsen syndrome (JLNS) is an autosomal recessive cardioauditory ion channel disorder characterized by congenital bilateral sensorineural deafness and long QT interval. JLNS is a ventricular repolarization abnormality and is caused by mutations in the KCNQ1 or KCNE1 gene. It has a high mortality rate in childhood due to ventricular tachyarrhythmias, episodes of torsade de pointes which may cause syncope or sudden cardiac death. Here, we present a 4.5-year-old female patient who had a history of syncope and congenital sensorineural deafness. She had a cochlear implant operation at 15 months of age and received an implantable cardioverter defibrillator (ICD) at 3 years of age because of recurrent syncope attacks. Five months after cochlear implant placement, she could say her first words and is now able to speak. With ß-blocker therapy and ICD, she has remained syncope-free for a year. On the current admission, the family visited the genetics department to learn about the possibility of prenatal diagnosis of sensorineural deafness, as the mother was 9 weeks pregnant. A diagnosis of JLNS was established for the first time, and a homozygous missense mutation in the KCNQ1 gene (c.128 G>A, p.R243H) was detected. Heterozygous mutations of KCNQ1 were identified in both parents, thereby allowing future prenatal diagnoses. The family obtained prenatal diagnosis for the current pregnancy, and fetal KCNQ1 analysis revealed the same homozygous mutation. The pregnancy was terminated at the 12th week of gestation. The case presented here is the third molecularly confirmed Turkish JLNS case; it emphasizes the importance of timely genetic diagnosis, which allows appropriate genetic counseling and prenatal diagnosis, as well as proper management of the condition.

Efficacy and safety of cryoablation of parahissian accessory pathways in children: a single institution study.

BACKGROUND: Catheter cryoablation of supraventricular tachycardias involving the perinodal regions is considered to be a safer alternative compared to radiofrequency ablation. Limited information is available for efficacy, midterm outcomes, and complications regarding the ablation of parahissian accessory pathways (APs) in pediatric patients. METHODS: A retrospective review of all pediatric patients who underwent cryoablation for treatment of a parahissian AP was performed. RESULTS: Twenty-five patients (median age 13 years and weight 45.6 kg) underwent cryoablation of a parahissian AP. Median number of cryolesions applied was four (range: 3-6). Initial procedural success was achieved in 23 patients (23/25, 92%). Transient third-degree atrioventricular (AV) block was noted in two patients. There was no permanent AV block. Transient right bundle branch block (RBBB) was observed in one patient and permanent RBBB occurred in two patients. Of the patients successfully ablated with cryo, there was only one recurrence (1/23, 4.3%) over a follow-up of 17.5 months (range 6-34 months). CONCLUSION: Cryoablation of parahissian APs is both safe and effective with a low risk of recurrence in pediatric patients.

The efficacy of amiodarone-propranolol combination for the management of childhood arrhythmias.

BACKGROUND: The aim of this study was to present our data regarding the efficacy and safety of combining amiodarone and propranolol for the management of arrhythmias in infants. METHODS: Children aged between 0 and 18 years who received combination therapy with amiodarone and propranolol for persistent monotherapy resistance tachyarrhythmia between 2007 and 2011 were included in the study. Treatment efficacy and adverse effects were evaluated by review of clinical signs and symptoms, 12-lead electrocardiogram, 24-hour Holter monitorization, liver enzymes, thyroid function tests, chest x-ray, and ophthalmologic examination. RESULTS: A total of 25 patients (15 male and 10 female) were enrolled in this study with a mean age of 17.9 months (0-132) and a mean weight of 8.65 kg (2.2-25). In 18 patients, treatment was started before their first age. Tachyarrhythmia persisted in two patients despite combination therapy, and treatment regimen was changed. Complete control of the arrhythmia was achieved within the first 2 months of combination treatment in 20 patients, whereas in the remaining three patients short attacks of tachycardia who responded to dose increases were controlled beyond 2 months of treatment and no recurrence were observed. Overall, success of amiodarone-propranolol combination treatment was 92%. Mild elevation in thyroid-stimulating hormone level was observed in one patient that required discontinuation of treatment. CONCLUSION: Our results suggest that a combination of amiodarone and propranolol is an effective and safe option for the treatment of persistent arrhythmias in neonates and infants, and may serve as a bridge to ablation therapy in older children.

Analysis of idiopathic ventricular tachycardia in childhood.

Idiopathic ventricular tachycardia (VT) is a relatively benign and rare form of VT. It is seen in young people without demonstrable cardiac pathology. The aim of our study was to review the clinical picture of idiopathic VT, before evaluating the indications for antiarrhythmic treatment and the efficacy of radiofrequency ablation (RFA). The notes of patients diagnosed with idiopathic VT in the last 13 years (n: 22) were included in the study. The median age of onset was 11 years (1 month-16 years). We evaluated the findings regarding the diagnosis, treatment and prognosis of these patients. The most common initial symptom was palpitation, in 15 cases. Five children with idiopathic VT were symptom-free. VT was of right ventricular origin in 10 patients and left ventricular origin in 8 patients. Beta-blockers were the mainstay of medical treatment in right VT and calcium channel blockers (Ca-channel blocker) were mostly used in left VT cases. The success rate of RFA was 57% in right VT and 100% in left VT. The median follow-up was 41 months (9 months-60 months), and all patients are alive currently with no symptoms. VT without demonstrable cardiac pathology is associated with a good prognosis. Treatment is unnecessary for asymptomatic non-sustained VT. RFA is useful in patients with symptomatic drug-refractory idiopathic VT arising from the left or right ventricle.

Clinical features and mid- and long-term outcomes of pediatric patients with subclinical carditis.

A study to examine mid- and long-term outcomes in patients with subclinical carditis was conducted. Data obtained at the time of diagnosis and during the follow-up of 158 patients diagnosed with subclinical carditis were retrieved and analyzed. Most patients had isolated mitral insufficiency. Frequency of morphological changes in the mitral valve was significantly lower in patients with at least one additional Jones criterion both at baseline (10.3% vs. 48.8%, p < 0.01) and at the end of the follow-up (27.8% versus 43.5%, p = 0.11). Mean jet size for mitral (12.0 +/- 8.8 versus 18.2 +/- 5.5 mm, p < 0.01) and aortic (4.1 +/- 4.0 versus 14.0 +/- 5.8 mm, p = 0.008) insufficiency were decreased compared to baseline. Improvement in mitral insufficiency was more frequent among patients with more than five years of follow-up (82.6% versus 60.0%, p = 0.039). Subclinical carditis due to acute rheumatic fever is not a benign and temporary condition. These patients should be given secondary prophylaxis.

Closure of the patent ductus arteriosus with the Amplatzer Duct Occluder II: a clinical experience.

BACKGROUND: The aim of our study was to share our clinical experience on cases with patent ductus arteriosus treated with the Amplatzer Duct Occluder II. METHODS: Between 2008 and 2012, 26 of 31 patients with patent ductus arteriosus underwent successful transcatheter closure of patent ductus arteriosus using the Amplatzer Duct Occluder II. Mean age was 3.3 years and mean weight was 15.7 kilograms. The presence of a residual shunt, left pulmonary artery or aortic obstruction was explored by administering contrast material during the procedure. The patients were discharged 24 hours after the procedure. RESULTS: The procedure was successful in 26 of 31 patients and failed in five patients. According to the Krichenko classification, 26 patients had type A, one patient had type B and 4 patients had type C ductus. The mean narrowest ductus diameter was 3.2 mm and the mean ductus length was 6.7 mm. Complete angiographic occlusion occurred immediately after the procedure in 22 out of 26 patients in whom the ductus was closed successfully with the Amplatzer Duct Occluder II. Complete occlusion was achieved in the remaining patients with residual shunt one month after the procedure. The procedure was preceded by closure with an Amplatzer Duct Occluder I in two patients and an Amplatzer Vascular Plug I in one patient. CONCLUSION: Amplatzer Duct Occluder II is highly effective in transcatheter closure of patent ductus arteriosus. We think that an alternative closure device and alternative techniques can be attempted in patients with type C ductus. The success rate could increase with accumulating experience.

Long-term inhaled iloprost use in children with pulmonary arterial hypertension.

BACKGROUND: We performed a retrospective analysis of patients with pulmonary arterial hypertension receiving inhaled iloprost in a single centre to evaluate long-term tolerability, safety, and efficacy of chronic inhaled iloprost therapy in children. METHODS: A total of 20 patients with either idiopathic or associated pulmonary arterial hypertension were treated with iloprost between April, 2003 and January, 2010. The median age and weight of the patients were 3.8 years--ranging from 4 months to 19 years--and 12.3 kilograms--ranging from 4 to 73 kilograms-- respectively. Pulmonary arterial hypertension was idiopathic or hereditary in eight patients (40%) and associated with congenital cardiac disease in 12 patients (60%). RESULTS: Of the 20 patients, 15 had combined therapy--12 patients with two and three patients with three different classes of drugs. In all, six patients died during follow-up. The median follow-up time was 18 months, ranging from 6 to 74 months. The 6-minute walking test was performed in 7 out of 20 patients at baseline and on follow-up. The median 6-minute walking test increased from 420 to 490 metres after iloprost therapy (p = 0.028). After initiation of iloprost therapy, one patient complained of headache and another had a rash around his mouth, none necessitating discontinuation of therapy. Overall compliance with inhaled iloprost was good. CONCLUSION: Pulmonary hypertension is associated with significant morbidity and mortality. Careful assessment of each patient and timely combination of specific vasodilator therapy is needed to improve clinical outcomes. This study suggests that inhaled iloprost, with or without concomitant endotelin receptor antagonist and/or phosphodiesterase inhibitor, is safe and efficacious for treatment of pulmonary arterial hypertension in children.

Midterm experience with implantable cardioverter-defibrillators in children and young adults.

AIMS: This single-centre study was undertaken to review our experience with implantable cardioverter-defibrillator (ICD) implantation in children with relatively different aetiologies. METHODS AND RESULTS: We retrospectively reviewed the records of the paediatric patients who underwent ICD implantation between October 2001 and December 2008. The data of these patients were collected by reviewing the patients' medical records and computerized departmental pacemaker databases. A total of 28 patients who underwent ICD implantation during this period were included in this study. The median age was 12 years and median weight was 32 kg. Most of the patients had ion-channel diseases (n = 13) or cardiomyopathy (n = 11). Devices were implanted for either secondary (n = 22) or primary (n = 6) prevention. The selected ICD generator type was single chamber in 22 patients, dual chamber in 5 patients, and biventricular in 1. Nineteen patients received 122 shocks. Fifteen of 22 patients (68.2%) from the secondary prevention group and 2 of 6 patients (33.3%) from the primary prevention group experienced at least one appropriate shock during a median period of 11.3 months (range: 4 days-6.5 years). Forty-two inappropriate shocks were delivered in seven (31.8%) patients from the secondary prophylaxis group during a median period of 11.3 months. The most important reason for inappropriate shocks was T-wave oversensing. In six patients, lead-related acute or chronic complications occurred. CONCLUSION: The ICD was safe and effective in interrupting malignant arrhythmias in children and adolescents with a high risk of sudden cardiac death. However, the occurrence of lead complications is significant. The incidence of therapies delivered by the device, with appropriate and inappropriate shocks, was high and interfered with the quality of life. The most important reason for inappropriate shocks was T-wave oversensing. Careful programming is mandatory to reduce the inappropriate shocks.