Pulmonary arterial hypertension associated with congenital heart disease: lessons learnt from the large Turkish Nationwide Registry (THALES)

Pulmonary hypertension is a group of diseases, including pulmonary arterial hypertension associated with congenital heart disease (APAH-CHD), characterized by progressive deterioration in pulmonary hemodynamics associated with substantial morbidity and mortality risk. THALES is a national multicenter, prospective observational registry, providing data on patients with APAH-CHD. The study comprised APAH-CHD patients (>3 months of age) with confirmed diagnosis of right heart catheterization or echocardiographic findings. Initial and follow-up data were collected via regular hospital visits. Descriptive statistics are used for definitive purposes. Overall, 1034 patients aged 3 months–79 years (median 11.2 [Q1–Q3: 2.2–24.3] years) with APAH-CHD were enrolled at 61 centers, 50.3% being retrospectively enrolled. Most had either Eisenmenger's syndrome (49.2%) or systemic-to-pulmonary shunts (42.7%). Patients were mostly in functional class I–II at the time of diagnosis (46.6%). Mean 6-min walk distance (6MWD) was 369 ± 120 m. Mean pulmonary arterial pressure was 54.7 ± 22.2 mmHg for the whole group, and was highest in patients with Eisenmenger's syndrome. Targeted therapies were noted in 398 (38.5%) patients (monotherapy in 80.4%). Follow-up data were available in 506 patients. Survival at 140 months was 79% and was associated with baseline 6MWD >440 m (p = 0.009), brain natriuretic peptide level < 300 ng/L (p < 0.001). Follow-up 6MWD >165 m (p < 0.0001), brain natriuretic peptide level <300 ng/L (p = 0.031), and targeted therapies (p = 0.004) were also predictive of survival. THALES is the largest registry dedicated to APAH-CHD to date and provides important contributions on demographics, clinical characteristics, and gaps in disease management.

Calmodulin mutations and life-threatening cardiac arrhythmias: insights from the International Calmodulinopathy Registry

AIMS

Calmodulinopathies are rare life-threatening arrhythmia syndromes which affect mostly young individuals and are, caused by mutations in any of the three genes (CALM 1-3) that encode identical calmodulin proteins. We established the International Calmodulinopathy Registry (ICalmR) to understand the natural history, clinical features, and response to therapy of patients with a CALM-mediated arrhythmia syndrome.

METHODS AND RESULTS

A dedicated Case Report File was created to collect demographic, clinical, and genetic information. ICalmR has enrolled 74 subjects, with a variant in the CALM1 (n = 36), CALM2 (n = 23), or CALM3 (n = 15) genes. Sixty-four (86.5%) were symptomatic and the 10-year cumulative mortality was 27%. The two prevalent phenotypes are long QT syndrome (LQTS; CALM-LQTS, n = 36, 49%) and catecholaminergic polymorphic ventricular tachycardia (CPVT; CALM-CPVT, n = 21, 28%). CALM-LQTS patients have extremely prolonged QTc intervals (594 ± 73 ms), high prevalence (78%) of life-threatening arrhythmias with median age at onset of 1.5 years [interquartile range (IQR) 0.1-5.5 years] and poor response to therapies. Most electrocardiograms (ECGs) show late onset peaked T waves. All CALM-CPVT patients were symptomatic with median age of onset of 6.0 years (IQR 3.0-8.5 years). Basal ECG frequently shows prominent U waves. Other CALM-related phenotypes are idiopathic ventricular fibrillation (IVF, n = 7), sudden unexplained death (SUD, n = 4), overlapping features of CPVT/LQTS (n = 3), and predominant neurological phenotype (n = 1). Cardiac structural abnormalities and neurological features were present in 18 and 13 patients, respectively.

CONCLUSION

Calmodulinopathies are largely characterized by adrenergically-induced life-threatening arrhythmias. Available therapies are disquietingly insufficient, especially in CALM-LQTS. Combination therapy with drugs, sympathectomy, and devices should be considered.

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.

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.

Use of urinalysis as a screening tool for asymptomatic infants

AIM

The utility of screening urinalysis in asymptomatic children has been questioned based on studies done in school-age children or adolescents. The American Academy of Pediatrics (AAP) recommended to abandon this screening in 2007 but many paediatricians perform it at some point during childhood. Thus, we aimed to investigate usefulness of screening urinalysis during infancy.

METHODS

We retrospectively reviewed results of screening urinalysis done in infants at 6-18 months of age who had regular care since birth at our centre. Infants with an ICD-10 (International Classification of Diseases, Tenth Revision) diagnostic code for routine child health exam (Z00.1) and a urinalysis requested with this code on the same date were included.

RESULTS

A total of 683 infants met the inclusion criteria. 44 (6%) had an abnormal urinalysis. The most common abnormality (n = 39, 5,7%) was pyuria. Of these 39 babies, 5 had a repeat urinalysis only, 18 had a repeat urinalysis with urine culture, and 16 had a urine culture alone. Six patients had positive culture results and were given antibiotic treatment. All six babies who received treatment had normal ultrasound and two patients had a voiding cystourethrography, which were also normal. The other abnormalities (n = 5) detected were microscopic hematuria and proteinuria. Repeat urinalyses of these patients were normal.

CONCLUSION

Screening urinalysis results were abnormal in 6% of the babies, but in 86% of those, abnormalities were transient. Only <1% had positive culture results. These data add to the evidence that screening urinalysis during infancy is unjustified supporting the AAP 2007 recommendations.

Isolated right superior vena cava draining into the left atrium

A 10-year-old male was admitted to our institution with complaints of mild cyanosis and dyspnea. Transthoracic echocardiography and angiography revealed a right superior vena cava (SVC) draining into the left atrium. At the time of surgery, the right SVC was connected to the right atrium.

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.

Catheter fragment embolization: a rare yet serious complication of catheter use in pediatric oncology

Embolization is a rare but serious complication of venous central catheters in pediatric oncology. The reported cases in the literature are due in common to catheter ruptures. The most common cause is constant compression of the costoclavicular arch, known as "pinch-off" syndrome. We report a seven-year-old boy in whom embolization occurred as a late complication. Difficulty in the dissection of dense collagen periportal fibrosis was the main problem during the extraction session. The embolization occurred 10 months later. In an elective setting, percutaneous retrieval techniques were used successfully to extract the catheter fragments, and full recovery was achieved.

Angiocardiography and magnetic resonance imaging to assess pulmonary regurgitation in repaired tetralogy of Fallot

OBJECTIVE

This study aimed to compare the results of angiocardiography and cardiovascular magnetic resonance imaging in the assessment of pulmonary regurgitation following repair of tetralogy of Fallot.

METHODS

We prospectively studied 37 patients with repaired tetralogy of Fallot. After routine examination cardiovascular magnetic resonance imaging (CMR) and cardiac catheterization and angiography were performed. Pulmonary regurgitation (PR) was classified according to the following criteria, using a left lateral angiogram of the main pulmonary artery; insufficiency jet is limited to right ventricular outflow tract (mild); jet reaches the body of right ventricle (moderate); jet fills the apex of the right ventricle (severe).

RESULTS

Pulmonary regurgitation determined by angiocardiography and CMR was severe in 51.4% and 32.4%, moderate in 27% and 40.5%, and none or mild in 21.6% and 27% of patients respectively. The ability of semi-quantitative estimation of PR determined by cardiac catheterization to distinguish between mild, moderate and severe pulmonary regurgitation was shown to have significant correlation with pulmonary regurgitant fraction obtained by CMR.

CONCLUSIONS

Angiography obtained during invasive study can be used for the diagnosis and follow-up of pulmonary regurgitation confidently in patients with repaired tetralogy of Fallot and residual pulmonary regurgitation.

Coronary microcatheter mapping of coronary arteries during radiofrequency ablation in children

INTRODUCTION

Radiofrequency catheter ablation (RFCA) is a safe and effective treatment option for children with refractory supraventricular tachycardias. RFCA of right-sided accessory pathways (APs) continues to be challenging, resulting in lower success rates and higher recurrence rates. One of the reasons for a prolonged or failed procedure is mapping error and changes in cardiac anatomy. The right coronary artery (RCA) runs along the ventricular aspect of the right epicardial atrioventricular groove, and RCA mapping had been reported facilitating difficult right-sided AP RFCA in the pediatric population. We reported that microcatheter-assisted mapping during RFCA can improve localization of right-sided and some left-sided APs particularly in children with congenital heart disease.

METHODS

This technique was used in seven patients with a mean age of 15.3+/-1.6 years and a mean weight of 52.6+/-6.5 kg. Five patients (71%) had manifest preexcitation on surface electrocardiogram, and two patients had a concealed AP. In two of them, there were single ventricle anatomies. In the other two patients, venous access problem to the heart and enormous cardiac hypertrophy were the major problems. In the remaining three patients with normal cardiac anatomy, RCA mapping was used because a standard procedure was not successful. Previous RFCA ablation was not successful in two patients. Either a 150-cm eight-electrode pair (2-6-2 mm, 2.5 French) or a four-electrode pair (2-6-2 mm, 2.3 French) microcatheter (2.3 French octapolar microcatheter) was used.

RESULTS

Average time of the multielectrode RCA mapping was 42+/-14.5 min. All eight (100%) APs were successfully ablated. No complications occurred.

CONCLUSIONS

Microcatheter-assisted coronary artery mapping during RFCA is a useful adjunctive mapping technique in children with difficult to map right-sided APs and patients with APs who has complex cardiovascular anomalies.

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).

Clinical importance of transesophageal electrophysiologic study in the management of supraventricular tachycardia in children

Transesophageal electrophysiologic study (TEEPS) is a semi-invasive method widely used for evaluation of symptoms related to arrhythmia. In this study, we aimed to determine the accuracy of TEEPS in the diagnosis and differentiation of mechanisms of supraventricular tachycardias (SVTs) by comparing results of transesophageal and intracardiac electrophysiologic studies. We performed TEEPS and a subsequent radiofrequency ablation (RFA) procedure in 76 patients. Indications of TEEPS were risk assessment for Wolff-Parkinson-White syndrome in 32 patients and diagnosis and differentiation of tachycardia mechanisms in 44 patients. The procedure was well tolerated in all patients. Positive predictive value of TEEPS in our study was 91% for differentiation of SVT mechanisms. The results suggest that TEEPS is safe, useful and effective in the evaluation of symptoms related to arrhythmia, in differentiation of mechanisms of SVTs, and finally in defining the treatment options of SVT. The technique also provides an opportunity for risk assessment and deciding the treatment modality in Wolff-Parkinson-White patients.

Transesophageal electrophysiologic study to determine the inducibility after successful ablation of supraventricular tachycardia in children

BACKGROUND

Radiofrequency ablation has become first-line therapy for supraventricular tachycardia in all age groups, but there has been a concern regarding the long-term effectiveness of the procedure in children. This study aimed to determine the inducibility after successful ablation of supraventricular tachycardia in children; assessment was performed using a transesophageal electrophysiologic study.

RESULTS

A total of 63 patients who had been treated successfully for supraventricular tachycardia with radiofrequency ablation were included in the study. A transesophageal electrophysiologic study was performed 2 months after radiofrequency ablation. Tachycardia was induced in nine of 34 symptomatic and five of 29 asymptomatic patients by a transesophageal electrophysiologic study. Ten patients had recurrence of the same type of supraventricular tachycardia seen previously, and two had a new type of arrhythmia during a transesophageal electrophysiologic study. Tachycardia inducibility rate was 16% in all patients, 22.8% in patients with atrioventricular reentrant tachycardia, and 8% in patients with atrioventricular nodal reentrant tachycardia.

CONCLUSION

Radiofrequency ablation is a safe and effective method to manage children with supraventricular tachycardia, but patients must be observed for recurrence and new arrhythmias. Sustained tachycardia may also be induced in asymptomatic patients. A transesophageal electrophysiologic study is effective and safe for follow-up of radiofrequency ablation for assessment, diagnosis, and treatment of patients.

Treatment of dilated cardiomyopathy with carvedilol in children

We performed a study to examine the clinical use of carvedilol, its dosage and its effects on systolic functions in children. Twenty-one patients with dilated cardiomyopathy who were treated with carvedilol adjacent to standard heart failure therapy were enrolled in the study. Echocardiographic assessment was obtained before and during carvedilol therapy, and left ventricular fractional shortening and left ventricular ejection fraction were determined in order to estimate left ventricular function. At a follow-up of six months, left ventricular ejection fraction and fractional shortening significantly improved from 38 +/- 10% to 53 +/- 13% and from 19 +/- 6 % to 27 +/- 8%, respectively, following carvedilol treatment. The results of the present study indicate that carvedilol is well tolerated in children with dilated cardiomyopathy and there is a significant improvement in the clinical status and left ventricular ejection fraction in patients not responding to conventional therapy. Patient selection criteria, optimal timing of carvedilol therapy, its dosage and its long-term effects need to be investigated with multi-institutional trials and large numbers of patients.

Endovascular stent implantation for coarctation of the aorta in children and young adults: intermediate follow-up results from Turkey

The aim of this study was to report the intermediate follow-up results of stent implantation for coarctation of the aorta in children from Turkey. Patients with native or postoperative coarctation, who had abnormal flow at the descending aorta exceeding diastolic phase on Doppler echocardiography or upper extremity hypertension, underwent endovascular stent implantation. Ten patients with a mean age of 12.4 +/- 5.5 years (6-23 years) underwent stent implantation between January 2001 and September 2006. Of these, three had previous surgical repair, and the remainder were native coarctation. Palmaz, Genesis and Numed CP stents were used. All the implantations were successful and there was no major complication during the procedure. The follow-up period was 8-72 months and only one patient needed re-dilatation during this period. Stent implantation may be a feasible alternative to balloon angioplasty and surgery for adolescents. Patients who have previous surgical repair, high surgical risk, unfavorable anatomy, or refuse consent for surgical intervention are the best candidates for stent implantation. However, longer follow-up and new studies are necessary especially in younger patients.

A case of congenital agenesis of the right pulmonary artery presenting with hemoptysis and mimicking pulmonary hemosiderosis

Congenital unilateral absence of a pulmonary artery is a rare anomaly most frequently accompanied by other cardiovascular anomalies. We report a 10-year-old girl presenting with fatigue and recurrent hemoptysis who was initially misdiagnosed with idiopathic pulmonary hemosiderosis. Her symptoms did not resolve despite treatment so she was referred to our center for further evaluation. We carried out an angiography which revealed the absence of the right pulmonary artery and multiple collaterals originating from the right subclavian and right internal mammary arteries supplying the right lung. During the follow-up the patient developed a severe episode of pulmonary infection and pulmonary hypertension which responded well to medical treatment. Physicians should be aware of the congenital absence of the right pulmonary artery especially in patients presenting with recurrent respiratory symptoms. Although this condition is generally considered to have a good prognosis, close observation is mandatory in order to prevent further complications and comorbidities.

Lead extraction in children and young adults using different techniques

OBJECTIVE

To describe our experience with removal of pacing lead in children using different techniques.

PATIENTS AND METHODS

Between 1999 and 2006, removal of 39 leads was attempted in 30 patients: 21 males and 9 females aged 4-21 years (mean 12 +/- 5 years). Sixteen patients had previous corrective cardiac surgery. The leads had been implanted for 46 +/- 31 months (range 1-120 months). The reasons for removal included lead fracture in 14, upgrading in 8, infection in 7, dislodgment in 5, pacing system not needed in 2, and other reasons in 3.

RESULTS

Of the 39 leads, 29 (74.3%) were completely removed. Twelve leads were removed with simple traction and rotation and 9 were removed using a locking stylet combined with simple traction and rotation; a laser extraction system was used in 10 cases in which 8 leads were successfully removed. Duration of implantation was the only important predictor for successful removal. Three patients necessitated surgical lead removal and had epicardial pacemaker implantation.

CONCLUSION

Using currently available techniques, percutaneous pacemaker lead removal was possible in the majority of cases, although a significant number of cases were not successful. Attempted lead removal with simple traction and rotation resulted in the need for surgical removal in a significant number of patients. Newer techniques should be developed to increase the success rate.

Congenital aortic stenosis: a novel technique for ventricular pacing during valvuloplasty

OBJECTIVES

The main objective of this study is to describe a new technique for rapid ventricular pacing to maintain balloon stability during balloon aortic valvuloplasty (BAV) without using transvenous temporary pacemaker electrode.

BACKGROUND

The safety and efficacy of rapid right ventricular pacing to facilitate balloon stability during BAV has been previously reported. However, it necessitates an additional femoral venous access, an additional sheath, and a temporary pacemaker electrode.

METHODS

This was a prospective pilot study. Rapid ventricular pacing was performed through back-up guidewires inserted into the left ventricle for balloon advancement and by an adhesive patch placed on the back of the patient. The technique was performed during BAV procedure in all of 15 consecutive children diagnosed as congenital aortic stenosis. Pacing was performed at a rate decreasing systolic aortic pressure to the point of 40-50% of baseline.

RESULTS

The technique was successful in all patients. Effective capture, stable pacing, and balloon stability were achieved in all children using very low outputs. No sustained arrhythmias or other procedure-related complications occurred. Mean aortic valve gradient decreased from 68.5 +/- 20.4 mm Hg to 20.4 +/- 10.2 mm Hg. Degree of aortic regurgitation progressed from grade 0 to 1 in three patients and remained unchanged in 12 patients.

CONCLUSIONS

This study demonstrated that back-up guidewires can be used effectively and safely for pacing during BAV procedures. This technique omits probable complications related to a second vascular access and may shorten the procedure time and decreases costs by eliminating the use of an additional sheath and a temporary pacemaker electrode.

Percutaneous closure of a prenatally diagnosed large coronary artery fistula with an Amplatzer vascular plug immediately after delivery

We describe successful percutaneous closure of a prenatally diagnosed large coronary fistula originating from the right coronary sinus and draining into the right ventricle in a one-day-old neonate using an Amplatzer vascular plug. Early intervention may be a useful tool in such cases with large fistulas to avoid complications such as severe congestive heart failure, myocardial ischaemia, need for assisted ventilation and longer hospital stay.

Premature ventricular contractions in normal children

Premature ventricular contractions (PVCs) are frequently seen in children with normal cardiac findings. The purpose of this study was to evaluate the characteristics and the prognosis of PVCs in children with normal heart. This study included 149 children with PVC who did not have systemic or cardiac disease. Their median age at diagnosis was 10 years (range 1 month to 17 years). Seventy-six children (51%) were symptomatic. Most of the patients had unifocal PVC, whereas 5 (3.1%) of them had multifocal PVCs. The patients were evaluated by repeated Holter recordings and exercise test. In the first Holter monitoring recordings, PVCs were in the form of isolated PVC in 122 (82%) patients, couplet-triplet in 14 (9%) patients and nonsustained ventricular tachycardia in 13 (9%) patients. The exercise test was performed in 105 (70.5%) patients. The frequency of PVCs decreased and disappeared in 65 (61.9%) children, increased in 8 (7.6%), and were unchanged during exercise in 32 (30.5%). There was no difference between the groups according to exercise response regarding PVC quantity. Fifty-two of 149 children (35%) were followed up for a median period of 22 months. After follow-up, PVCs of 25 of the 52 patients (48.1%) decreased and disappeared. We did not find any correlation between the frequency of PVC and treatment, age, gender or the PVC frequency decrease with exercise. In conclusion, PVCs in normal children have benign prognosis and during follow-up a considerable percent show improvement.

Device closure of congenital ventricular septal defects with Amplatzer devices: first experiences in Turkey

Ventricular septal defects (VSD), which cause volume overload, may be closed by interventional method. The success depends on the precise anatomic definition of the defect and its relation to other cardiac structures. We report our first experiences of transcatheter closure of perimembranous and muscular VSD. Between May 2005 and September 2006, transcatheter closure of VSD was attempted in 38 patients. Implantation was successful in 37 patients. In one patient, the procedure failed because of the long sheath kinking. We observed important complications in three patients: severe tricuspid valve regurgitation, residual VSD and tricuspid valve regurgitation and right bundle branch block in the short-term follow-up. Transcatheter device closure with Amplatzer device seems to be effective and safe in the treatment of perimembranous and muscular VSDs. Tricuspid valve incompetence may cause problems. Long-term results are required to determine the efficacy and safety.

Transvenous cardiac pacing in children: problems and complications during follow-up

OBJECTIVE

Transvenous permanent cardiac pacing (TPCP) has become a frequently used therapeutic modality in children. The purpose of this study was to evaluate the outcome of pediatric TPCP regarding problems and complications.

METHODS

Records of 155 patients (mean age 9.2+/-4.7 years) who underwent implantation of TPCP between 1993 and 2003 were reviewed retrospectively. Indications for pacing included atrioventricular block in 76% and sinus node dysfunction in 22% patients. In 92 patients, bradyarrhythmia was secondary to cardiac surgery. Percutaneous subclavian puncture was used for lead implantation in 96% of patients. Pacemakers were placed to the right side of the chest in 84% and in the subpectoral area in 68%. Pacing modes were VVIR in 72%, VDD in 13%, AAIR in 8%, and DDD in 7% of patients at the initial implantation time. Of all electrodes, 95% had steroid elution and 53% had an active fixation mechanism. Mean follow-up period was 37+/-28 (1-120) months.

RESULTS

Forty-five (29%) patients had 21 minor and 45 major complications. Forty-four of 76 revisions were due to lead problems and battery extraction. Most of the lead problems were dislodgment and stretching (n=14). Kaplan Meier analysis of lead survival did not show any difference between lead types. During the follow-up, there were three sudden unexpected deaths.

CONCLUSIONS

In children, TPCP can be used safely and effectively. Although, complications are possible and sometimes lead or generator revision may be necessary, long-term outcome is favorable.

Septated pericarditis associated with Kawasaki disease: a brief case report

Kawasaki disease (KD) is primarily the systemic vasculitis of childhood that affects mainly the medium-sized arteries, such as the coronary arteries. KD is the leading cause of acquired heart disease, whereas the incidence of rheumatic fever has declined. The most serious complication is coronary artery involvement. Among the children with KD who developed cardiac complications, pericarditis is a rare complication, with an incidence of 0.07%. We report our experience in a 5.5-year-old child with KD complicated with aneurysm of the left anterior descendant coronary artery and septated pericardial effusion, which has not been reported in the literature. The pericardial effusion disappeared very dramatically with intravenous immunoglobulin (IVIG) therapy. We would like to point out that septated pericardial effusion in cases of KD do not need any further therapy other than IVIG and high-dose acetylsalicylic acid.

The effects of sevoflurane and desflurane anesthesia on QTc interval and cardiac rhythm in children

BACKGROUND

Inhalational anesthetics may prolong QTc interval (QT interval corrected for heart rate) of the ECG and cause life-threatening arrythmias. The effects of desflurane on QTc interval and cardiac rhythm have not been reported previously in children. We assessed the effects of desflurane anesthesia on QTc interval and cardiac rhythm and compared them with sevoflurane anesthesia in children.

METHODS

The study was performed on 20 children admitted for inguinal hernia repair, with normal QTc intervals. Anesthesia was induced with propofol and intubation was achieved with vecuronium. Anesthesia was maintained with 2% sevoflurane (group I, n = 11) or 6% desflurane (group II, n = 9) and 66% nitrous oxide in oxygen. Electrocardiogram recordings were obtained by Holter recorder. QTc intervals were measured at baseline, 5, 10, 15, and 30 min after inhalation.

RESULTS

None of the patients had significant arrythmia with desflurane anesthesia. One patient in the sevoflurane group had single, bigemini and multiform ventricular extrasystoles. There was no statistically significant difference in the baseline QTc values of the groups. Desflurane significantly prolonged QTc interval 5 min after induction until 30 min of anesthesia compared with baseline values (P = 0.029), while no significant prolongation was observed with sevoflurane (P = 0.141).

CONCLUSIONS

Use of 2% sevoflurane during maintenance of anesthesia does not significantly prolong QTc interval while 6% desflurane significantly prolonged QTc interval in children with normal QTc interval undergoing inguinal herniorrhaphy.

Demonstration of coronary arteries and major cardiac vascular structures in congenital heart disease by cardiac multidetector computed tomography angiography

BACKGROUND

Detection of coronary artery is important when considering surgical treatment of a congenital heart disease (CHD) such as tetralogy of Fallot (TF). Cardiac catheterization plays an important supplementary role in the evaluation of patients with CHD. In a few reports, it has been proposed that multidetector computed tomography (MDCT) can be helpful for the visualization of coronary arteries. We sought to demonstrate the feasibility and usefulness of MDCT angiography for anatomical evaluation of coronary arteries in CHD patients with suspected coronary artery anomalies.

MATERIALS AND METHODS

A total of 10 patients, 9 pediatric and 1 adult, underwent MDCT angiography for the investigation of coronary artery anomalies and mediastinal vascular structures. Seven patients had TF; 5 of these patients were suspected of having coronary artery anomalies and 2 were suspected of having pulmonary artery atresia or a nonconfluent pulmonary artery. The other 3 patients had truncus arteriosus and severe left pulmonary artery stenosis (n = 1), double outlet right ventricle (n = 1), and Kawasaki disease (n = 1) with suspected coronary artery aneurysms. The entire heart, major vascular structures, and coronary artery anomalies were preoperatively scanned in patients with cyanotic heart disease. Examinations were performed by 16-MDCT with 1-mm slice thickness. A breath-holding test was performed in 5 patients. Nonionic iodinated contrast material (2 cc/kg) was administered by a power injector.

RESULTS

Major vascular structures and the proximal part of the right and left coronary arteries were visualized successfully in all patients. Mid and/or distal segments of the coronary arteries were visualized in 5 patients with TF. Pulmonary vascular bed findings were also confirmed during surgery in patients with TF and in one patient with truncus arteriosus type I and severe left pulmonary artery stenosis. Kawasaki disease was diagnosed by the presence of aneurysms in one patient. Pulmonary artery atresia was confirmed in one patient and diameter of the pulmonary arteries (4 mm and 4.5 mm) was determined in the other 2 patients by MDCT.

CONCLUSION

The advantage of MDCT for cardiac imaging is the shortened scanning time for imaging the entire heart without long breath-holding times. Selective conventional coronary angiography is invasive and technically difficult in pediatric patients. We suggest that MDCT angiography can be performed as a noninvasive method in patients with CHD for the evaluation of coronary artery anatomy and anomalies and mediastinal vascular structures.

Cardiac Index and Exercise during VDD/DDD versus VVIR Pacing in Children

Twelve children with a VDD/DDD pacemaker during 100, 125, 150, 200 ms atrioventricular delays and VVIR pacing, cardiac index was measured at rest and evaluated by endurance time during exercise stress test. The optimal atrioventricular delay, which provides highest cardiac index, was 100 ms in three, 125 ms in two, and 150 ms in four and 200 ms in three patients. VDD/DDD pacing with different atrioventricular intervals resulted in a significantly higher cardiac index (6.70 +/- 3.06, 6.49 +/- 2.51, 6.15 +/- 2.35, 6.37 +/- 2.69 l/min/m(2), respectively) than VVIR pacing (5.25 +/- 2.39 l/min/m(2)) at the rest. However, endurance times to treadmill exercise were similar in both the optimal atrioventricular delay (21.6 +/- 3.7 min) and VVIR mode (22.4 +/- 3.4 min) (p > 0.05).

Transesophageal electrophysiologic study in children and young patients

Transesophageal electrophysiologic study (TEEPS) is a semi-invasive method of atrial stimulation and recording. The aim of the study was to report our experience with TEEPS in children and young adults. A total of 153 TEEPS were performed in 147 consecutive patients aged between 26 days to 26 years (mean 9.8 years) with the following indications: evaluation of symptoms that may be signs of any arrhythmias in 89 procedures (Group A), risk assessment of Wolff-Parkinson-White syndrome (WPW) in 17 procedures (Group B), determination of the mechanism of previously detected or ongoing tachycardia on ECG or Holter monitoring in 22 procedures (Group C), assessment of antiarrhythmic therapy effectiveness in 17 procedures (Group D), and follow-up of radiofrequency ablation procedure (RFA) in 8 procedures (Group E). A similar pacing protocol was performed for induction of tachycardia in each patient. Tachycardia was induced in a total of 72 procedures (72/153, 47%): 32/89 (36%) in Group A, 13/17 (76.5%) in Group B, 12/22 (54.5%) in Group C, 12/17 (70.6%) in Group D and 3/8 (37.5%) in Group E. In Group A, the ventriculoatrial (VA) interval of inducible tachycardia was found to be shorter than 70 msec in 16/32 (50%) and longer than 70 msec in 12/32 (37.5%) patients and these patients were diagnosed as having atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT), respectively. In this group, 1 atrial tachycardia, 2 junctional ectopic tachycardia, 1 sinus node reentrant tachycardia and 1 permanent junctional reciprocating tachycardia (PJRT) were also diagnosed. In conclusion, transesophageal atrial stimulation is a valuable tool in the initial evaluation of patients with symptoms possibly related with arrhythmia or in the management of patients who have any arrhythmia.

Isolated noncompaction of left ventricular myocardium with fetal sustained bradycardia due to sick sinus syndrome

Noncompaction of the ventricular myocardium is a rare congenital cardiomyopathy resulting from an arrest in normal endomyocardial embryogenesis. This disease is characterized by numerous and prominent trabeculations and deep intertrabecular recesses. It may be isolated or associated with other congenital heart diseases. The disorder is clinically accompanied by depressed ventricular function, systemic embolization and arrhythmias. Sustained bradycardia is infrequent in prenatal life and associated with maternal collagen vascular diseases, structural heart diseases or long QT syndrome. Herein we report a case of isolated noncompaction of left ventricular myocardium diagnosed in the first day of life and followed previously by serial fetal echocardiograms for the sustained sinus bradycardia. On postnatal electrocardiography, there was junctional escape rhythm due to profound sinus bradycardia, leading us to consider sick sinus syndrome. To our knowledge, this is the first case in the literature of isolated noncompaction of left ventricular myocardium with sustained bradycardia due to sick sinus syndrome.

Complex venous anomalies: magnetic resonance imaging findings in a 5-year-old boy

We report magnetic resonance imaging (MRI) findings of a very unusual venous anomaly case. A 5-year-old boy who had surgical repair of coarctation of the thoracic aorta was referred to our department for evaluation of an enlarged venous structure anterior to the aorta, which had been noted during the surgery. Contrast enhanced dynamic MRI revealed partial anomalous pulmonary venous return to the left azygos vein, double inferior and superior vena cava with the left azygos continuation of the left superior vena cava. The recognition of venous anomalies allows correct planning of surgical and interventional procedures. MRI is a valuable imaging tool providing detailed anatomical information.

Single-pass lead VDD pacing system in children and adolescents: report of twenty-four patients

The dual-chamber pacing systems allow for AV synchrony, but generally require the placement of two separate transvenous leads. Single-lead atrioventricular synchronous pacing system (VDD) using single-pass leads has been accepted as therapeutic alternative for atrioventricular block with normal sinus node function. The aim of this study is to evaluate clinical performance of single-pass lead VDD pacing systems in 24 consecutive patients in a ten-year period. The study group includes 17 (70.8%) male and 7 (28.8%) female patients. The mean age and mean weight during pacemaker implantation was 10.4 +/- 3.8 years (4-17 years) and 30 +/- I I kg (13.5-55 kg), respectively. The patients have been followed for 7-84 months (median 42 months). The percentage of atrial sensing-ventricular pacing changed from 75 to 99.9% at the last control. During the follow-up period, pacing mode was changed to VVIR due to complete loss of AV synchrony in five patients (21%). Four of them had underlying cardiac disease. In these patients loss of AV synchrony might be related to cardiac enlargement/abnormal cardiac anatomy or small atrial dipole-ventricular tip length. Despite the loss of AV synchrony in post surgical AV block or dilated cardiomyopathy, single-lead VDD pacing systems can be successfully used in children with complete AV block and normal sinus node function. Patients and lead selection should be taken into consideration for the maintenance of AV synchrony.

Active-fixation, steroid-eluting ventricular leads: the medium-term results in children

OBJECTIVE

Low threshold characteristics and mechanical stability are important features of an ideal pacing lead, especially for children. We report our experience and medium-term results with a steroid-eluting, active-fixation ventricular lead in children.

METHODS

Telectronics Accufix II DEC model 033-212 ventricular leads were implanted in 21 patients. Eighteen patients (11 male / 7 female; 10.6+/-4.0 years), who were followed for a mean period of 6.47 +/-1.13 years, were included in the study.

RESULTS

Pacemaker mode was DDDR in three patients, and VVIR in the remaining 15 patients. Mean threshold value was 0.5 volts at implant, which increased to 0.7 volts in the first month (p>0.05). It remained stable (0.62-0.78 V) until 5.5 years (p>0.05), increased significantly at 5.5 years (0.99+/-0.63 V at 5.5 years, p<0.05) and remained significantly high after this time (p<0.05). Pacing lead impedance did not differ significantly throughout the study (p>0.05). Thirteen pulse generators reached end-of-life at > or =4 years. In all the patients whose generators were replaced (11 patients), the leads were kept in place.

CONCLUSION

Steroid-eluting active-fixation ventricular leads have long service lives and low chronic stimulation threshold values, allowing lower outputs. These features may have advantages in pacing therapy of children.