Leonardo Liberman

Pediatric nonpost-operative junctional ectopic tachycardia medical management and interventional therapies.

OBJECTIVESnTo determine the outcomes of medical management, pacing, and catheter ablation for the treatment of nonpost-operative junctional ectopic tachycardia (JET) in a pediatric population.nnnBACKGROUNDnNonpost-operative JET is a rare tachyarrhythmia that is associated with a high rate of morbidity and mortality. Most reports of clinical outcomes were published before the routine use of amiodarone or ablation therapies.nnnMETHODSnThis is an international, multicenter retrospective outcome study of pediatric patients treated for nonpost-operative JET.nnnRESULTSnA total of 94 patients with JET and 5 patients with accelerated junctional rhythm (age 0.8 year, range fetus to 16 years) from 22 institutions were identified. JET patients presenting at age < or =6 months were more likely to have incessant JET and to have faster JET rates. Antiarrhythmic medications were utilized in a majority of JET patients (89%), and of those, amiodarone was the most commonly reported effective agent (60%). Radiofrequency ablation was conducted in 17 patients and cryoablation in 27, with comparable success rates (82% radiofrequency vs. 85% cryoablation, p = 1.0). Atrioventricular junction ablation was required in 3% and pacemaker implantation in 14%. There were 4 (4%) deaths, all in patients presenting at age < or =6 months.nnnCONCLUSIONSnPatients with nonpost-operative JET have a wide range of clinical presentations, with younger patients demonstrating higher morbidity and mortality. With current medical, ablative, and device therapies, the majority of patients have a good clinical outcome.

Percutaneous pericardial instrumentation for catheter ablation of focal atrial tachycardias arising from the left atrial appendage.

Focal atrial tachycardias originating from the left atrial appendage present unique anatomic challenges for successful ablation. We describe the role of minimally invasive percutaneous epicardial mapping and ablation in the management of two patients with ectopic atrial tachycardias arising from the left atrial appendage following failure of a conventional endocardial approach to achieve cure.

Ultrasound-assisted cannulation of the right internal jugular vein during electrophysiologic studies in children.

Percutaneous access of the right internal jugular vein for coronary sinus cannulation in pediatric patients undergoing electrophysiologic studies may be technically difficult. We report the use of an ultrasound-guided technique for obtaining jugular venous access. Forty-five pediatric patients who underwent electrophysiologic study were analyzed. Access was obtained in 100 % of the patients using this technique with no major complications. Ultrasound guidance for access of the internal jugular vein for coronary sinus cannulation during electrophysiologic studies in pediatric patients, may increase the success rate and prevent the development of complications.

Fascicular and Nonfascicular Left Ventricular Tachycardias in the Young: An International Multicenter Study

The aim of this study was to evaluate the clinical presentation and outcomes of pediatric patients with ventricular tachycardia (VT) originating from left heart structures.

Lone Atrial Fibrillation in the Young – Perhaps Not So “Lone”?

OBJECTIVEnTo determine if pediatric patients with a history of lone atrial fibrillation (AF) have other forms of supraventricular tachycardia (SVT) that may potentially trigger AF.nnnSTUDY DESIGNnA multicenter review of patients with lone AF who underwent electrophysiology (EP) study from 2006-2011 was performed.nnnINCLUSION CRITERIAnage ≤21 years, normal ventricular function, structurally normal heart, history of AF, and EP study and/or ablation performed.nnnEXCLUSION CRITERIAncongenital heart disease or cardiomyopathy. Patient demographics, findings at EP study and follow-up data were recorded.nnnRESULTSnEighteen patients met inclusion criteria. The mean age was 17.9xa0±xa02.2 years, weight was 82xa0±xa021 kg, body mass index was 27xa0±xa06, and 15 (83%) were males. Eleven (61%) were overweight or obese. Seven (39%) had inducible SVT during EP study: 5 atrioventricular nodal re-entry tachycardia (71%) and 2 concealed accessory pathways with inducible atrioventricular re-entry tachycardia (29%). All 7 patients with inducible SVT underwent radiofrequency ablation. There were no complications during EP study and/or ablation for all 18 patients. The mean follow-up was 1.7xa0±xa01.5 years and there were no recurrences in the 7 patients who underwent ablation. There were 2 recurrences of AF in patients with no other form of SVT during EP study.nnnCONCLUSIONSnInducible SVT was found in 39% of pediatric patients undergoing EP study for lone AF. EP study should be considered for pediatric patients presenting with lone AF.

Long QT syndrome due to a novel mutation in SCN5A: treatment with ICD placement at 1 month and left cardiac sympathetic denervation at 3 months of age

We describe the case of a newborn with congenital long QT syndrome, with 2:1 AV block and frequent episodes of Torsades de Pointes (TdP) requiring placement of a dual chamber ICD at 33xa0days and 3.63xa0kg, the youngest and smallest patient, thus far reported. Long QT syndrome was diagnosed due to bradycardia in the newborn nursery, with frequent episodes of TdP. The patient was initially treated with magnesium and esmolol then given lidocaine which resulted in dramatic transient normalization of the QTc with 1:1 AV nodal conduction. An attempt to transition to oral sodium channel and beta blockade was unsuccessful. An ICD was placed and dual chamber pacing was initiated which facilitated the transition to an oral medical regimen and ultimate discharge from the hospital. Soon after placement of the ICD, genetic testing revealed a novel F1473C mutation in the SCN5A gene. Episodes of TdP continued and left stellate gangliectomy was performed at 3xa0months of age. At 30xa0months follow-up, the patient has occasional, self-limited episodes of TdP and has received rare, successful, and appropriate ICD shocks.

Predictors for hemodynamic improvement with temporary pacing after pediatric cardiac surgery

OBJECTIVESnTemporary epicardial pacing wires are commonly placed during pediatric cardiac surgery. Data are sparse on postoperative pacing in this population. The objective of this study was to determine the frequency of use and identify predictors for the use of temporary epicardial pacing wires.nnnMETHODSnPerioperative data were prospectively collected on all patients who underwent cardiac surgery at our institution (n = 162).nnnRESULTSnA total of 117 (72%) patients had temporary epicardial pacing wires placed. Postoperatively, 23 (20%) of 117 patients had hemodynamic improvement with the use of temporary epicardial pacing wires. Indications for pacing were slow junctional rhythm (11/23 [48%]), junctional ectopic tachycardia (7/23 [31%]), pace termination of supraventricular tachycardia (3/23 [13%]) and atrial flutter (1/23 [4%]), and complete heart block (1/23 [4%]). By using univariate analysis, single-ventricle anatomy, heterotaxy, the Fontan procedure, use of circulatory arrest, intraoperative arrhythmia, pacing in the operating room, and use of vasoactive medications were predictors for hemodynamic improvement with the use of temporary epicardial pacing wires (P < .05). On multivariate analysis, the Fontan procedure, circulatory arrest, and intraoperative arrhythmias were independent predictors (P < .01). When excluding all patients with any of these 3 risk factors, only 2% were paced. Patients with clinically significant pacing had longer chest tube drainage (P < .01) and intensive care unit length of stay (P < .01). There were no complications associated with temporary epicardial pacing wires.nnnCONCLUSIONSnThe Fontan procedure, use of circulatory arrest, and intraoperative arrhythmias were associated with hemodynamic improvement with postoperative pacing and might represent indications for empiric intraoperative placement of temporary epicardial pacing wires. Patients without these risk factors were less likely to require pacing. Temporary epicardial pacing wires were safe and useful in the management of arrhythmias after pediatric cardiac surgery.

Late Onset of Heart Block After Open Heart Surgery for Congenital Heart Disease

Late onset of complete heart block is a potentially dangerous complication after open heart surgery for congenital heart disease. The characteristics of patients with late-onset heart block have not been well described. A retrospective review of a pacemaker database was done to identify patients who presented with new onset heart block between 1988 and 2006, after they had been discharged from the hospital after open heart surgery with normal AV conduction. Fifteen patients were identified. The age at the time of the last surgery before the onset of heart block was 2.0 ± 3.2 years (range: 3 days to 10 years). Nine had a ventricular septal defect repair, four had an atrioventricular canal, and two other patients had other types of heart defect. The last EKG available for analysis before the onset of heart block had been obtained 5.1 ± 6.5 years (range: 7 days to 16 years) after surgery. The symptoms at the time of presentation were variable. Four patients presented with fatigue or exercise intolerance, two with syncope, two with congestive heart failure, and one with irritability, and the remaining six patients were diagnosed during routine follow-up. The time between open heart surgery and placement of a permanent pacemaker was 6.8 ± 7.3 years (range: 2 months to 19 years). There were seven patients in whom the onset of heart block was more than 6 years after surgery. Late onset of complete heart block after open heart surgery could be dangerous when presenting without warning. These data would support the notion that patients should be followed for life after repair of congenital heart defects, with special attention to the conduction system, particularly after repair of septal defects.

Complete Heart Block Due to Lyme Carditis in Two Pediatric Patients and a Review of the Literature

Carditis is a common manifestation of adult patients with Lyme disease affecting 4-10% of Lyme patients in the United States. However, children with Lyme disease rarely present with acute carditis. The management of pediatric patients with complete heart block (CHB) secondary to Lyme carditis has not been well described. We report the acute management of 2 pediatric patients that presented in CHB secondary to Lyme disease.

Relation of the Utility of Exercise Testing for Risk Assessment in Pediatric Patients With Ventricular Preexcitation to Pathway Location

The gradual loss of ventricular preexcitation during exercise stress testing (EST) has an unclear risk of an association with life-threatening arrhythmia and could be related to the accessory pathway (AP) location. We compared the loss of preexcitation during EST with the risk assessment during invasive electrophysiology testing and determined whether the loss of preexcitation correlates with the AP location. We retrospectively reviewed patients aged ≤21 years with ventricular preexcitation who had undergone both EST and an electrophysiology study. The patients were divided into 3 groups: sudden loss (SL), gradual loss (GL), or no loss (NL) of preexcitation during EST. A total of 76 patients were included, with 11 (14%) in the SL group, 18 (24%) in the GL group, and 47 (62%) in the NL group. The SL group demonstrated a longer cycle length with 1-to-1 conduction by way of the AP during incremental atrial pacing compared with the NL group (375 ± 135 ms vs 296 ± 52 ms, p = 0.002), with no difference between the GL and NL groups (325 ± 96 vs 296 ± 52 ms, p = NS). Of the patients with 1-to-1 AP conduction of <270 ms, none (0 of 11) were in the SL group compared to 18 of 47 in the NL group (p = 0.0017), with no significant difference in the GL group (5 of 18) compared to the NL group (p = NS). The patients in the GL group were more likely to have a left-sided AP (14 of 18) than the NL group (17 of 47, p = 0.002) and the SL group (3 of 11, p = 0.002). In conclusion, a sudden loss of preexcitation during an EST predicted a long cycle length with 1-to-1 conduction by way of the AP. Also, the AP conduction characteristics in patients with GL compared to those with NL did not differ, and the GL of preexcitation was more frequently seen in patients with a left-sided AP.