Follow up of a family with asymptomatic compound long QT syndrome mutations.

Long QT syndromes (LQTS) are a cause of syncope and sudden death and present as a long QT interval on the surface ECG. The mortality of the condition may be quite variable among affected individuals. Hundreds of mutations in more than ten genes are identified as responsible for almost all patients with LQTS. Compound mutations are reported in different series as 4.5 and 7.9% and are associated with poor outcome. Beta blockers are the mainstay of therapy. The use of intracardiac defibrillators (ICD) is widely considered in patients at high risk for sudden death. Herein, we report a case of LQTS with compound mutations of KCNQ1 and SCN5a. Although ICD implantation was advised due to high cardiac event risk, the patient followed with beta blocker treatment for 15 years without any syncope or palpitations.

Peripheral neuropathy in a patient with D-2-hydroxyglutaric aciduria.

D-2-hydroxyglutaric aciduria (D-2-HGA; OMIM 600721) is a rare autosomal recessive neurometabolic disorder with a wide clinical spectrum. The severe phenotype is homogeneous and is characterized by early infantile-onset epileptic encephalopathy with hypotonia, delayed cerebral visual development, cardiomyopathy and facial dysmorphic features. The mild phenotype has a more variable clinical expression with hypotonia and developmental delay. We present peripheral neuropathy as an additional clinical and electrophysiological feature in a 16-year-old boy with a homozygous missense mutation in exon 3 of the D-2-hydroxyglutarate dehydrogenase gene (D2HGDH) at position c.458T>C. This mutation results in replacement of a methionine residue, which was highly conserved during evolution, by threonine (p.Met153Thr).

MR angiography of left-sided cervical aortic arch with aberrant right subclavian artery.

Cervical aortic arch is a rare anomaly. We report the contrast-enhanced MR angiography features of left-sided cervical aortic arch with contralateral descending aorta and aberrant right subclavian artery in a 16-year-old girl.

Unusual extraction of an active fixation ventricular pacing lead with outer coil fracture in a child.

AIM: In this report we describe an asymptomatic paced child with outer coil fracture of the bipolar screw-in steroid eluting ventricular lead without insulation defect, loss of ventricular capture and unexpected increase in lead impedance in the bipolar VVIR pace configuration. METHOD AND RESULT: A previously unpublished method was performed to retract the helix and the lead. As a result, the fractured lead was successfully retrieved. CONCLUSION: We suggest that, this unusual extraction method can be tried as an alternative approach in the removal of an active fixation ventricular pacing lead with impaired mechanical function possibly due to fracture.

Thrombosis in children with cardiac pathology: frequency of factor V Leiden and prothrombin G20210A mutations.

This study analyzed 28 thrombotic children with various cardiac disorders. They comprise 17% of a total of 168 patients with thrombosis from a single center. Among the 28 patients, 21 had congenital heart disease and 7 were diagnosed with cardiomyopathy. The patients with thrombosis were evaluated for congenital and acquired thrombotic risk factors. In addition to cardiac disorders, two, three, or more risk factors were present in 61% of the children with thrombosis. Two common mutations, namely factor V Leiden and prothrombin G20210A mutations, were found in 6 patients (22%). Nine patients (32%) died of infection, congenital heart disease, cardiomyopathy, thrombosis, operation, or a combination of these; two patients required surgical intervention. Following cardiac angiography, due to necrosis, amputation of the right index finger and right lower extremity was performed on 1 patient. The second patient's index fingers had to be amputated and resection of the bowel was performed following the operation on coarctation of the aorta. This study indicates that congenital heart disease and cardiomyopathy are two common cardiac disorders that may lead to the development of thrombosis. The majority of thrombosis develops within the heart and/or its great vessels. The second predominant site for thromboembolic symptoms is in the brain, including sinovenous thrombosis.

Sotalol in treatment of pediatric cardiac arrhythmias.

BACKGROUND: There is limited experience on sotalol use in the management of childhood arrhythmias. This study reviews the results of our experience with oral sotalol for treatment and prevention of tachyarrhythmias in children. METHODS: The records of 62 patients (27 female, 35 male, mean age: 8.5+/-5.3 years) treated with sotalol for supraventricular or ventricular arrhythmias from 1994 to 1999 at our institution were reviewed. Demographic, clinical, echocardiographic, electrocardiographic (ECG), ambulatory ECG and electrophysiologic variables were collected. RESULTS: Forty-two (63.6%) patients had re-entrant supraventricular tachycardia, eight patients (12.9%) had atrial tachycardia, one patient (1.6%) had junctional ectopic tachycardia, four patients (6.5%) had ventricular tachycardia, and seven patients (11.3%) had complex ventricular arrhythmias, as evidenced by surface or ambulatory ECG records; or revealed during the electrophysiological study. The mean sotalol dose was 3.9+/-1.2 mg/kg per day. In 15.5+/-13.9 months of sotalol use 50% (n=31) had complete relief of symptoms and/or arrhythmia and 29% (n=18) had partial relief. Sotalol was ineffective in 20% (n=13). Sotalol was more effective in re-entrant type supraventricular tachycardias (P=0.012). Sotalol was the first choice in 35.5% of patients. The sotalol therapy was initiated in inpatient settings in 40.3% (25 patients). Complications due to sotalol were seen in six patients (five patients developed bradycardia/pauses, and one patient had torsades de pointes) for which the sotalol dose was modified. In patients with sick sinus syndrome, a pacemaker was implanted and in another patient sotalol was stopped. CONCLUSION: Sotalol, being an effective and safe drug particularly in children, is a good therapeutic alternative for the preventive treatment of childhood tachyarrhythmias.

A late complication with the CardioSEAL ASD occluder device and need for surgical revision.

A late complication of the CardioSEAL atrial septal defect (ASD) occluder is reported. Although left atrial umbrella was completely epithelialized and occluded ASD without residual defect, the right atrial umbrella protruded toward the center of right atrium after 18 months. We believe this may be associated with the structural abnormality of the device.

Preliminary pediatric transesophageal echocardiography experiences.

With transesophageal echocardiography (TEE), a new echocardiographic window is obtained which enables cardiologists to explore the heart from the esophagus and stomach. However, the procedure, when first undertaken, may present certain difficulties for the cardiologist in interpreting the anatomical findings and approaching a diagnosis. We thus convey our first experiences and results of TEE in 107 pediatric patients. Transesophageal echocardiography (TEE) was performed in 107 pediatric patients at our institution between December 1998-February 2001, using the standard techniques and following the standard criteria suggested by the American heart Association. The mean age of 54 male (50.5%) and 53 female (49.5%) patients was 7.8 years. Intubation difficulty was experienced in four cases. In one case, while drawing the transducer back from the esophagus, it kinked at the hypopharynx. None of the cases had major hemorrhage or esophageal rupture, and only a few cases had minor pharyngeal injuries or hemorrhages. We used TEE in detecting vegetations in patients with possible endocarditis, and evaluating the prosthetic valves and abnormal pulmonary venous return. We also used TEE to clarify preooperative anatomical details, postoperative complications and residual defects of complex congenital cardiac anomalies. Transcattheter closure of 47 secundum atrial septal defects (ASD)'s and a muscular ventricular septal defect (VSD) (both during patient selection and during the procedure) were accomplished under TEE guidance. As the pediatric cardiologists gain more experience in performing TEE, this technique will have a wider and more effective use in the pediatric population.

Anomalous origin of one pulmonary artery branch from ascending aorta ("so-called hemitruncus"): report of an additional case treated surgically.

The aortic origin of one pulmonary artery branch, so-called hemitruncus, is a rare congenital anomaly with poor prognosis. In this report, an additional patient is presented. The patient, a 60-day-old male infant with the right pulmonary artery originating from the ascending aorta was operated successfully. Postoperative catheterization demonstrated normal flow to the right lung and pulmonary artery pressure decreased to normal level.

Isolated noncompaction of ventricular myocardium.

Isolated noncompaction of the ventricular myocardium is a rare congenital cardiomyopathy resulting from an arrest in normal endomyocardial embryogenesis. The diagnosis can be made echocardiographically, and the entity may be associated with problems of cardiac rhythm. We describe two illustrative cases, with Wolf-Parkinson-White syndrome in one, and left bundle branch block in the other. We emphasize that children with problems of rhythm and findings suggestive for left ventricular cardiomyopathy, either hypertrophic or dilated; should be investigated to exclude isolated noncompaction of the ventricular myocardium.

Transcatheter closure of secundum atrial septal defects, a ventricular septal defect, and a patent arterial duct.

We report our clinical experience with the newly developed Amplatzer device in transcatheter closure of nine atrial septal defects (ASDs), one ventricular septal defect (VSD), and one patent arterial duct (PDA). Eleven patients with ASD (age range 2.5-18 years) selected according to the location and size of the defect by transesophageal echocardiography (TEE), a five-year-old patient with muscular VSD and a one-year-old patient with PDA were considered for transcatheter closure with Amplatzer devices. All procedures were performed under general anesthesia with fluoroscopic and TEE guidance, following a routine hemodynamic evaluation in the catheter laboratory. The optimal device size was selected after the balloon sizing of the ASDs. The sizes of the VSD and PDA were measured on TEE and angiography. The patients were discharged at 24 hours, after an evaluation with x-ray, electrocardiogram (ECG), and echocardiography; they were on 3-5 mg/kg/day aspirin and infective endocarditis prophylaxis for six months after the procedure. They were reassessed at six to eight weeks and Holter monitoring was done in addition. Devices were used for nine ASD patients, and for the VSD and the PDA patients. Mean ASD size was 14.3 +/- 5.3 mm at TEE and 18.3 +/- 4.3 mm at balloon sizing (p=0.02). The mean size of the device was 18.7 +/- 4.2 mm. The procedure time and the fluoroscopy time were 46.1 +/- 12.3 and 12.9 +/- 1.6 minutes, respectively. Immediately after the procedure, four patients (44%) had trivial shunts (TS). TS remained in only two during discharge, and no shunt was observed at second evaluation. The devices were similarly applied to VSD (12-7 mm) and PDA (8-6 mm) patients. Both cases had TS immediately, which disappeared at 24 hours. None of the patients had major complications. Junctional rhythm developed in one patient, and another patient had frequent supraventricular extrasystoles. Amplatzer is an effective and safe device for transcatheter closure of ASD, VSD, or PDA, especially in pediatric patients.

Endovascular stent implantation in congenital heart defects.

We report the immediate and short-term results of endovascular stent implantations from our center. We performed stent implantations in four patients (3, 12, 18 and 20 years old) with different stenoses or obstructions: right ventricular outflow conduit obstruction, left Blalock-Taussig obstruction, post-operative recoarctation and cavopulmonary anastomosis obstruction. Stent were implanted successfully. The mean diameters of stenoses were expanded from 4.5 +/- 3.5 (2-7) mm to 9 +/- 1. 2 (8-10) mm, and the complaints of patients were improved significantly by stent implantation. There was no complication related to the procedures. All patients are living except one who died from cerebrovascular event unrelated to the stent implantation. The mean follow-up period of three living patients is 6.3 +/- 5.5 (1-2) months. As of the last control, all have remained at the caliber achieved at original placement. In light of our limited experience and previous reported studies, we conclude that intravascular stents are safe and can be used effectively in selected patients with congenital heart defects.

The effect of recombinant human erythropoietin on serum selenium levels in hemodialysis patients.

Succesful results in the treatment of anemia, one of the main complications of chronic renal failure, can be achieved by the use of recombinant human erythropoietin (RhEPO), which is available almost fifteen years in clinics. On the other hand, as both chronic renal failure and maintenance hemodialysis reduce the levels of trace elements, this study was designed to evaluate the interaction potential of RhEPO with serum concentrations of selenium (Se) during four months. Thirty one adult hemodialysis outpatients participated in the study. Ten of them, not on any drug therapy to interact with RhEPO, recruited as "Control Group", and the remainder, on RhEPO therapy, as "RhEPO Group". Blood was drawn from the Control Group at the beginning of the study, and from the RhEPO Group at every month for four months. Serum erythropoietin leveLs were measured by a radioimmunoassay method and Se status by a spectrofluorometric method. It was found that Se levels were not affected by RhEPO treatment during 3 months of therapy, while an increase was seen on the fourth month. The observation indicates that the increase in serum Se levels would be significant in longer than three-month RhEPO treatment.

A surgical approach on an emergency basis for removal of Wilms' tumor with intracardiac neoplastic extension.

Extension of Wilms' tumor through inferior vena cava into the heart two years after the completion of therapy, is a very rare clinical aspect. We successfully operated on a 7 year old girl who had a huge right atrial mass which filled the right ventricle and right ventricular out flow tract, on an emergency basis using cardiopulmonary bypass.

Comparison of mid-term clinical experience with steroid-eluting active and passive fixation ventricular electrodes in children.

Although active fixation ventricular leads seem to have advantages over passive fixation leads, this study compares the follow-up results of active and passive fixation leads in children. We evaluated the implantation and follow-up data of 41 children with active (Accufix II DEC, group 1) (n = 20) or passive (Membrane E, group 2) (n = 21) fixation, steroid-eluting ventricular leads. All but one of the patients in group 1 completed the 12-month follow-up. The mean follow-up period in group 2 was 10.4 +/- 2.9 months (range 3-12 months, median 12 months). In both groups the mean pacing threshold was measured as 0.51 +/- 0.09 V versus 0.48 +/- 0.15 V (P > 0.05) at 0.5-ms pulse width, mean R wave amplitude as 9.9 +/- 2.5 mV versus 9.4 +/- 3.2 mV (P > 0.05), and mean impedance as 557 +/- 92 omega versus 664 +/- 160 omega (P < 0.05), respectively, at implantation. After the first week of pacing, mean threshold values in group 1 were significantly lower than those of group 2 (P < 0.01 and P < 0.05, respectively). During the follow-up period, lead impedance measurements did not show a significant difference between the two groups. In one patient from group 1, the lead (by unscrewing) was removed easily because of pacemaker pocket infection. No lead dislodgement or helix deformation occurred in group 1. Nevertheless, in one patient from group 2, the lead was extracted at 4-month postimplantation because of lead displacement. We conclude that the steroid-eluting active fixation lead (Accufix II DEC) have advantages of easier implantation and lower acute and chronic stimulation thresholds compared to the passive fixation lead (Membrane E). Therefore, Accufix II DEC is superior to Membrane E, and it is a better first choice in children with an implanted single chamber ventricular pacemaker.

Evaluation by exercise testing of children with mild and moderate valvular aortic stenosis.

BACKGROUND: The aim of the present paper was to determine the factors related to sudden death in aortic stenosis. METHODS: The factors related to sudden death were investigated in 40 asymptomatic children with mild and moderate aortic stenosis by treadmill testing. RESULTS: The QT interval of aortic stenosis cases were significantly longer than those of healthy children with increasing heart rates during exercise. CONCLUSIONS: A longer QT interval of aortic stenosis cases compared to normal children during exercise is the first sign of myocardial ischemia and leads to fatal ventricular arrhythmias and sudden death. For this reason we recommend that exercise testing should be performed frequently in aortic stenosis patients and that close follow up is necessary for patients with long QT segments that can be a marker for severe arrhythmias.

Analysis of 2017 Holter records in pediatric patients.

Holter monitoring (HM) is widely used in arrhythmic disorders of adult patients; however, studies in the pediatric age group are limited. This study aims to determine the value of HM in diagnosis and treatment of disorders related to arrhythmias in pediatric patients. We examined 2,017 Holter records of 1,500 children who applied to our institution between November 1994 and October 1998. The age ranged from 0-24 years (52% male, 48% female). The indications for HM were screening for arrhythmic symptoms (palpitation, chest pain, syncope) in 67 percent, monitoring dysrhythmic therapy in 17 percent, postoperative control in five percent, and pacemaker control in four percent. Palpitation is the leading presenting symptom, with more frequent findings of supraventricular extrasystole (SVE), supraventricular tachycardia (SVT), ventricular extrasystole (VE) and complete heart block (CHB) when compared to other symptoms. Only 5.3 percent of the patients had arrhythmic symptoms during monitoring and asymptomatic patients had more frequent arrhythmias. SVT, VE, and CHB are more frequent findings in the abnormal heart with previous cardiac operations. The diagnostic yield is low with arrhythmic symptoms in the pediatric age group; however, HM enables cumulative evaluation of heart rhythm and rhythm variability, which is important in diagnosing silent arrhythmias in high risk groups (abnormal heart, postoperative heart).

Congenital sick sinus syndrome with breath holding and severe syncope episodes during infancy. A case report.

Sick sinus syndrome is a rare cause of bradycardia in children without structural heart disease. A case of profound sinus bradycardia, sinus arrest with junctional escape, and pauses in a two-year-old infant with breath-holding and syncope episodes is presented. As a result of these clinical symptoms and electrocardiographic findings, the patient with sick sinus syndrome underwent implantation of transvenous ventricular pacemaker. He has been well and asymptomatic since the insertion of the pacemaker. In the differential diagnosis of an infant with breath-holding and syncope episodes, when these symptoms in particular cannot be explained by other common reasons, sick sinus syndrome should be kept in mind. This case also illustrates the importance of electrocardiographic studies for the diagnosis.

Dilatation of a restrictive interatrial communication using a balloon angioplasty catheter.

Balloon atrioseptostomy is a life-saving procedure palliating certain congenital heart defects like transposition of the great arteries, right or left atrioventricular valve atresia, hypoplastic left heart syndrome, and pulmonary hypertension. Occasionally the Rashkind balloon septostomy technique may be ineffective in creating an adequate interatrial communication. We performed balloon dilatation of a restricted atrial septal defect using a balloon angioplasty catheter in a three-month-old infant.