Search

Background: Permanent pacemaker (PM) implantation is performed for various indications and by different techniques in children; however, many problems with lead performance are encountered during follow‐up. This study aims to evaluate the possible effects of different lead types and implantation techniques on pacing at early and midterm in children with a permanent PM. Patients and methods: Pediatric patients who underwent permanent PM system implantation at our tertiary cardiac surgery center between January 1, 2010 and January 1, 2020 were evaluated retrospectively. Patients were categorized in the epicardial pacing lead (EP), transvenous pacing lead (TP), and transvenous bipolar lumenless (Select Secure [SS]) lead groups according to the lead implantation technique and lead type with the same manufacturer. Groups were evaluated statistically for demographic features, pacing type and indication for implantation, lead electrical performance, lead failure, complications, and outcome. Results: Over 10 years, 323 lead implantations were performed on 167 patients (96 males, median age 68 months [5 days‐18 years]). Of 323 leads, 213 (66%) were EP, 64 (20%) were TP, and 46 (14%) were SS. Of the total, 136 of the leads were implanted in atria, and 187 were implanted in ventricles. Primary pacing indications were postoperative complete atrioventricular (AV) block (n = 95), congenital AV block (n = 71), sinus node dysfunction (n = 13), and acquired complete AV block (n = 1). Additional cardiac diseases were present in 115 patients (69%). No statistically significant difference was observed in gender, syndrome, or pacing indication (P >.05). Atrial and ventricular capture, threshold, sensing, and lead impedance measurements were not significantly different at the initial and follow‐up periods (P >.05). The median follow‐up duration was 3.3 years (6 months‐10 years). Twenty lead failures were determined in 15 patients (EP: 14 lead failures in 10 patients; TP: two lead failures in two patients; and SS: four lead failures in three patients) during follow‐up, and no statistically significant difference was found between groups (P =.466). The 5‐year lead survival was 98% for TP, 95% for EP, and 90% for SS; the 10‐year lead survival was 90% for TP, 70% for EP, and 70% for SS. There was no mortality related to chronic pacing or due to the procedure of implantation. Conclusions: Despite improvements in technology, lead failure is still one of the most critical problems during these patients' follow‐up. Early to midterm lead survival rates of all three lead types were satisfactory. [ABSTRACT FROM AUTHOR]

Background Cryoablation is increasingly utilized in children because of its safety profile. Recently, larger catheter tips have been more widely used to improve long-term success rates. The aim of this study was to assess the safety and efficacy of 8-mm-tip catheters for cryoablation of right-sided accessory pathways (APs) in children. Methods Electrophysiological procedures were performed using the EnSite™ system (St. Jude Medical Inc., St. Paul, MN, USA). Results Between July 2010 and July 2014, 54 patients (mean age: 13.1 ± 3.7 years) underwent cryoablation using an 8-mm-tip catheter. In 18 of 54 (33%) patients where an 8-mm-tip catheter was the first-choice catheter, the success rate was 18 of 18 (100%). There was a history of previous failed attempts or recurrence with radiofrequency ablation and/or 6-mm-tip cryoablation in 36 of 54 (67%) patients. The success rate in these patients was 24 of 36 (67%). No fluoroscopy was used in 34 of 54 procedures. The recurrence rate was six of 42 (14%) during a mean follow-up period of 32 ± 15 months. In one patient, transient atrioventricular block occurred. Conclusions Cryoablation with an 8-mm-tip catheter for right-sided APs in children who weigh over 40 kg appears to be safe and acutely effective in cases where conventional ablation methods fail and also as a first choice for ablation procedure. However, the recurrence rate still seems to be high. [ABSTRACT FROM AUTHOR]

Background The features of pediatric patients with postoperative transient and permanent complete atrioventricular (AV) block (CAVB) were compared. Methods Patients who developed CAVB in postoperative period after congenital cardiac surgery between 2010-2015 were included in the study. They were classified as patients with transient CAVB and with permanent CAVB. The demographics and perioperative and postoperative variables of the groups were evaluated. Results A total of 1,550 patients underwent surgery during the study period. CAVB was determined in 96 patients (6.2%) in the early postoperative period: 66 had transient CAVB, 30 had permanent CAVB that necessitated pacemaker implantation. The median body weight and age at surgery were similar in both groups. The most frequent diagnosis was tetralogy of Fallot (TOF, n = 22), complete AV septal defect (AVSD, n = 15), and ventricular septal defect (n = 13). Junctional ectopic tachycardia (JET) developed in 27 patients with transient CAVB and in four with permanent CAVB (P < 0.05). There were no significant differences in the congenital cardiac pathology, the cardiopulmonary bypass time, cross-clamp time, and the presence of preoperative arrhythmia between the groups (P > 0.05). The duration of intensive care unit stay was 6 days (range 2-25) for patients with transient CAVB and 13 days (range 4-90) for patients with permanent CAVB. The duration of hospital stay was 10 days (range 2-33) for patients with transient CAVB and 20 days (range 10-90) for patients with permanent CAVB. Both were significantly longer in the patients with permanent CAVB. Conclusions Complete AVSD and TOF are the most risky operations for the development of postoperative AV block. Ninety-seven percent of the patients with transient CAVB regained AV conduction within the first 10 postoperative days. The high incidence of JET in patients with transient CAVB was striking. [ABSTRACT FROM AUTHOR]

Background: Systemic-pulmonary shunts are widely used in initial palliation in cyanotic congenital heart disease. The incidence and the relationship between acute shunt obstruction and thrombophilia are not precisely defined. The aim of this study was to determine the frequency of shunt obstruction in the early postoperative period, and to define the frequency and presence of thrombophilia factors in patients treated for acute shunt thrombosis. Methods: Between October 2010 and October 2012, 77 patients who had systemic-pulmonary shunt operation were included in this prospective study. Patients who developed shunt obstruction were examined in terms of inherited and acquired thrombophilia factors. Results: Median patient age was 61 days and median weight was 4.3 kg. Thirty-three patients were neonates. Diameter of the Gore-Tex grafts used for the shunt ranged from 3mm to 5mm. Acute shunt occlusion rate was 10% (8/77), and all of these occurred in the first 24 h. Thrombophilia was found in three of eight patients who underwent intervention (surgical and/or transcatheter) due to shunt thrombosis (presence of anti-phospholipid antibodies, n = 1; protein C deficiency, n = 1; and factor V Leiden mutation, n = 1) and only one patient died. Conclusions: Acute shunt obstruction developed in 10% of patients who underwent systemic-pulmonary shunt, and emergency surgery or transcatheter intervention can be life saving in this context. Acute shunt obstruction can occur due to mechanical and hemodynamic problems, but clinicians should also consider and evaluate thrombophilia factors. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to examine the effects of atomoxetine on heart rhythm using 12-lead electrocardiography (ECG) and 24 h Holter monitoring. Methods: Children and adolescents who were diagnosed with attention deficit-hyperactivity disorder according to DSM-IV-TR were referred to a pediatric cardiology clinic for cardiologic examination before and after 4 or 5 weeks of atomoxetine treatment. Cardiac examination, complete blood count, biochemistry, thyroid function tests, 12-lead ECG and 24 h Holter monitoring were performed routinely in all patients. Each subject underwent 24 h Holter ECG monitoring before atomoxetine was started and after 4 or 5 weeks of effective dose atomoxetine treatment. Results: Forty-one patients were included in this prospective study. No statistically significant change was found in QT, QTc or QT interval dispersion or blood pressure before and after 4 or 5 weeks of atomoxetine treatment. There was a statistically significant increase in heart rate (both during the day and at night) and QRS duration, and a statistically significant decrease in P wave dispersion. Three patients had rhythm disturbances. All of these three patients were asymptomatic and none of these arrhythmias reached clinical significance. Conclusion: Atomoxetine did not cause significant changes in ECG or Holter variables. In two patients, who had undiagnosed subclinical extrasystoles, extra beats were increased after 4th week of treatment, but still remained clinically insignificant. Before and after atomoxetine treatment, listening to the heart sounds for a longer time, may help clinicians to notice an extra beat. If an extra beat is identified then 24 Holter monitoring is recommended. [ABSTRACT FROM AUTHOR]

Background We evaluated the preoperative, operative and postoperative risk factors affecting early mortality in patients who underwent total correction of tetralogy of Fallot (TOF). Methods One hundred and twenty-two TOF patients who underwent reparative surgery between January 2010 and November 2013 were enrolled in the study. Results Mean patient age and weight was 2.3 ± 2.5 years and 11.3 ± 6.4 kg, respectively. Cardiac catheterization was performed in 101 patients (83%),and coronary anomalies were found in 11 patients. Mean McGoon index, pulmonary annulus z-score, main pulmonary artery z-score, left pulmonary artery z-score and right pulmonary artery z-score were 2.0 ± 0.4, -1.85 ± 1.54, -2.84 ± 2.06, 1.17 ± 1.73, and 0.74 ± 1.57, respectively. Total reparative surgery with a transannular patch was performed in 97 patients (79.6%); the rest underwent valve-sparing surgery. Median duration of postoperative mechanical ventilation, intensive care and hospital stay were 19 h, 3 days and 9 days, respectively. Extracorporeal membrane oxygenation (ECMO) was required in 10 patients in the postoperative early period. Arrhythmias occurring in the early postoperative period were junctional ectopic tachycardia (n = 13), complete atrioventricular block(n = 10; permanent epicardial pacemaker implanted in four) and ventricular tachycardia (n = 4). Nine patients died in the early postoperative period (7.3%). Parameters found to be associated with increased mortality were low preoperative oxygen saturation; high right ventricular/aortic pressure ratio immediately after surgery; presence of coronary anomaly; requirement of postoperative ECMO; and pacemaker ( P = 0.02, P = 0.04, P = 0.01, P = 0.0001, P = 0.03, respectively). Conclusions Poor preoperative oxygenation, presence of coronary anomaly, complete AV block in the early postoperative period, high RV pressure and requirement of ECMO appear to be the most significant factors that affect early mortality in the surgical treatment of TOF. Appropriate preoperative assessment, correct surgical strategies and attentive intensive care monitoring are required in order to reduce mortality. [ABSTRACT FROM AUTHOR]

Background Syncope is a frequent complaint in children and adolescents and may be a significant sign of serious pathology. Although patient history, family history, and physical examination are sufficient to reach a diagnosis in most cases of syncope, the cause of syncope still cannot be determined after initial investigation in one-third to half of all patients. The aim of this study was to evaluate the diagnostic yield of implantable loop recorder ( ILR) in children with unexplained syncope. Methods A retrospective review was carried out of clinical data, indications, findings, and a final management strategy in patients who underwent ILR implantation. Results A total of 12 patients with a mean age of 9.4 ± 4.5 years underwent ILR (Reveal Plus; Medtronic) implantation. ILR implantation indication was syncope in all of the patients. Family history, routine cardiac assessment, including resting 12-lead electrocardiogram, transthoracic echocardiography, 24 h Holter recording, and event recorder findings, were normal with the exception of one patient with (previously corrected) tetralogy of Fallot. After an average of 20 months (range, 1-36 months), six patients developed symptoms. ILR memory showed torsades de pointes-ventricular fibrillation ( n = 3), catecholaminergic polymorphic ventricular tachycardia ( n = 1), asystole and ventricular tachycardia ( n = 1), and normal sinus rhythm ( n = 1). At the time of writing six patients were still in follow up with no symptoms after an average of 25.2 months. Conclusion Implantable loop recorder plays an important role in the diagnosis of life-threatening arrhythmias in which syncope is otherwise unexplained. ILR implantation should be remembered in children whose symptoms are strongly correlated with rhythm disturbances. [ABSTRACT FROM AUTHOR]

Background Dexmedetomidine (DEX) is a highly selective alpha-2-adrenergic agonist approved for short-term sedation and monitored anesthesia care in adults. Its effects on the electrocardiography and cardiac conduction tissue are not well described in the literature. Therefore, we aimed to characterize the electrocardiographic and electrophysiologic effects of DEX in children. Methods Twenty children (11 boys and nine girls) between the ages of eight and 17 undergoing electrophysiology study and ablation of the supraventricular tachycardia had hemodynamic and cardiac electrophysiologic variables measured before and during the administration of DEX (1 microgram/kg IV over 10 minutes followed by a 10-minute continuous infusion of 0.5 microgram/kg/h). Results A significant decrease in heart rate was seen after the administration of DEX, but the systolic-diastolic-mean arterial pressure, respiratory rate, and end-tidal carbon dioxide did not change. Corrected sinus node recovery times and baseline sinus cycle lengths, which are markers of sinus nodal function, were both lengthened with the administration of DEX. Atrioventricular (AV) nodal function, as evidenced by the Wenckebach cycle length, the ventriculoatrial block cycle length, and AV nodal effective refractory periods, was lengthened significantly. We also found that DEX increased the atrial refractory period and diminished atrial excitability. Conclusions DEX significantly depressed sinus and AV nodal function in pediatric patients without significant electrocardiogram interval changes, other than a trend toward lower heart rates. Although no spontaneous AV nodal block and no clinically significant bradycardia were seen, we recommend that DEX be used with caution in patients at risk for bradycardia and/or AV nodal dysfunction due to its associated comorbidities. [ABSTRACT FROM AUTHOR]

Background The presence of Mahaim accessory pathways (MAP) with anterograde decremental conduction is a disorder that leads to antidromic atrioventricular reentrant tachycardia. There are rare reports of cryoablation use in MAP. This study aims at sharing our experience with using cryoablation to treat MAP in children. Methods Electrophysiology study and catheter ablation were performed in 14 patients diagnosed with Mahaim tachycardia between January 2010 and December 2013. Cryoablation was used in nine of the cases. A three-dimensional navigation system with surface electrode patches (EnSite System, St. Jude Medical Inc., St. Paul, MN, USA) was used for all procedures. Results The patients (two girls and seven boys) had a median age of 11.5 years (8-18 years) and a median weight of 67 kg (31-80 kg). Mahaim conduction was localized in the right posterolateral (n = 4), right lateral region (n = 2), right posteroseptal (n = 1), right anterolateral (n = 1), and right anterior (n = 1). A pathway potential was noted in six of nine cases at the tricuspid annulus. Catheter choices and acute success rates were as follows: cryoablation in four (three of four successful), radiofrequency catheter ablation (RFA) and cryoablation in five (successful in four of five). No fluoroscopy was used in six of nine patients. The mean procedure duration was 249 ± 90 minutes. No major complications were observed. The final long-term success rate for cryoablation was seven of nine (78%). Conclusions Cryoablation can be used as a reliable and effective alternative to RFA in the treatment of Mahaim accessory conduction pathways in children. Prospective comparative studies are necessary in order to further evaluate the long-term efficacy of this method. [ABSTRACT FROM AUTHOR]

Background The aim of this study was to examine the causes of cardiac tamponade in children undergoing percutaneous pericardiocentesis. Method Patients who presented with other complaints but were diagnosed with cardiac tamponade based on clinical and echocardiographic findings between January 2010 and January 2013 were retrospectively investigated. Electrocardiography, telecardiography and transthoracic echocardiography were performed. Pericardiocentesis was performed percutaneously under continuous blood pressure and rhythm monitoring with echocardiography and fluoroscopy. Pericardial fluid was analyzed on hemography and biochemistry. Results Fourteen patients (six boys, eight girls; median age, 7 years) underwent pericardiocentesis for cardiac tamponade. At presentation, 78% had dyspnea, 56% chest pain, and 49% fever. All had cardiomegaly, and their cardiothoracic index was 0.56-0.72. Also, all patients had sinus tachycardia; 78%, low QRS voltage; 70%, ST- T changes; and 50% QRS alternans. On echocardiography the widest diameter of pericardial effusion was between 12 mm and 36 mm depth around the heart. The pericardial fluid was purulent in one, serohemorrhagic in seven, serofibrinous in two, and serous in four cases. Pericardiocentesis was unsuccessful in two patients, who underwent open surgical drainage, with no complications. Based on pericardial fluid characteristics and additional tests, cardiac tamponade was caused by an infection in five patients, hypothyroidism in two, familial Mediterranean fever in two, malignancy in one, acute rheumatic fever in one, collagen tissue disease (systemic lupus erythematosus) in one, catheter placement-associated damage in one, and idiopathic pulmonary arterial hypertension in one patient. Conclusion Pericardial effusion and cardiac tamponade in children have varied causes, and early treatment is life saving. [ABSTRACT FROM AUTHOR]