Daniela Righi

Ventricular pre-excitation: symptomatic and asymptomatic children have the same potential risk of sudden cardiac death

AIMS Children and adolescents with ventricular pre-excitation (VPE) are at increased risk for sudden cardiac death (SCD). Although antiarrhythmic therapy and catheter ablation are well established temporary or definitive treatments for patients with Wolff-Parkinson-White (WPW) syndrome, the optimal management of children with asymptomatic VPE remains to be clearly defined. On the basis of the most recent guidelines and recommendations, the aim of this study was to determine the electrophysiological characteristics of young patients with VPE and WPW syndrome to assess and compare their potential risk of SCD. METHODS AND RESULTS We retrospectively investigated 124 consecutive young patients with VPE (51 with WPW syndrome and 73 asymptomatic) who underwent transoesophageal electrophysiological study. At baseline, atrioventricular reentrant tachycardia (AVRT) was induced in 13 WPW vs. 10 asymptomatic patients (25.5 vs. 13.7%, P = NS). Atrial fibrillation (AF) was induced in 13 WPW vs. 15 asymptomatic patients (25.5 vs. 20.5%, P = NS). A shortest pre-excited R-R interval (SPERRI) ≤250 ms during AF was found in four WPW vs. six asymptomatic patients (30.8 vs. 40%, P = NS). During isoproterenol infusion or stress testing, AVRT was induced in 31 of 44 WPW vs. 33 of 69 asymptomatic patients (70.4 vs. 47.8%, P = 0.018). Atrial fibrillation was induced in 12 of 44 WPW vs. 21 of 69 asymptomatic patients (27.3 vs. 30.4%, P = NS). A SPERRI ≤ 210 ms was found in 6 of 12 WPW vs. 10 of 21 asymptomatic patients (50 vs. 47.6%, P = NS). No statistically significant correlation was observed between accessory pathway location and symptoms, AVRT/AF inducibility, or mean APERP/SPERRI values. CONCLUSION Children and adolescents with WPW syndrome have a higher rate of AVRT inducibility than asymptomatic patients. However, no differences between the two groups were found in atrial vulnerability and parameters related to the risk of SCD.

Cryoablation of AVNRT in children and adolescents: early intervention leads to a better outcome.

Currently, transcatheter cryoablation is a well‐established technique for the treatment of atrioventricular nodal reentry tachycardia (AVNRT) in children. In the past decade, many studies have focused on identifying factors that may affect acute and long‐term outcome, but none has been shown to be strongly predictive of treatment success. The aim of our study was to determine whether patient age and cryoablation method correlate with acute and long‐term success.

Cryoablation of right-sided accessory pathways in children: report of efficacy and safety after 10-year experience and follow-up

AIMS The aim of this study was to report the 10-year experience of our Institution in cryoablation of supraventricular tachycardia due to a right accessory pathway (AP). METHODS AND RESULTS Seventy-one cryoablations of right AP were performed between July 2002 and October 2011 in our Institution in 66 patients (mean age 12 + 3 years, 56% males). Acute procedural success rate was 97%: 80% in patients with concealed AP and 100% in those with manifest AP (P < 0.05). Acute procedural success rate was not related to institutional experience. No permanent complication occurred. Sixteen patients had recurrences during the follow-up (18.6 ± 6.6 months; range 3-111), 13 within the first month of follow-up, 2 within the 6 months of follow-up, and 1 within 12 months of follow-up. Cox regression showed that sex, patient age, number of delivered cryo-bonus, and presence of manifest or concealed AP are not independent predictors of procedural success. Among the 16 patients with recurrences, in 10 a cryoablation redo was successful and with no further AP recurrences. The mean fluoroscopy time was 28.4 min (range 19.7-44.6) with a significant decrease (P = 0.033) in relation to the increase of the institutional experience. There were no permanent ablation-related complications. CONCLUSION Cryoablation of right-sided AP is effective and very safe in children. Better results are achieved in manifest AP. The learning curve has a real impact in the attempt to reduce the fluoroscopy time.

Comparison of cryoablation with 3D mapping versus conventional mapping for the treatment of atrioventricular re-entrant tachycardia and right-sided paraseptal accessory pathways.

UNLABELLED Aim Transcatheter cryoablation is a well-established technique for the treatment of atrioventricular nodal re-entry tachycardia and atrioventricular re-entry tachycardia in children. Fluoroscopy or three-dimensional mapping systems can be used to perform the ablation procedure. The aim of this study was to compare the success rate of cryoablation procedures for the treatment of right septal accessory pathways and atrioventricular nodal re-entry circuits in children using conventional or three-dimensional mapping and to evaluate whether three-dimensional mapping was associated with reduced patient radiation dose compared with traditional mapping. METHODS In 2013, 81 children underwent transcatheter cryoablation at our institution, using conventional mapping in 41 children - 32 atrioventricular nodal re-entry tachycardia and nine atrioventricular re-entry tachycardia - and three-dimensional mapping in 40 children - 24 atrioventricular nodal re-entry tachycardia and 16 atrioventricular re-entry tachycardia. RESULTS Using conventional mapping, the overall success rate was 78.1 and 66.7% in patients with atrioventricular nodal re-entry tachycardia or atrioventricular re-entry tachycardia, respectively. Using three-dimensional mapping, the overall success rate was 91.6 and 75%, respectively (p=ns). The use of three-dimensional mapping was associated with a reduction in cumulative air kerma and cumulative air kerma-area product of 76.4 and 67.3%, respectively (p<0.05). CONCLUSIONS The use of three-dimensional mapping compared with the conventional fluoroscopy-guided method for cryoablation of right septal accessory pathways and atrioventricular nodal re-entry circuits in children was associated with a significant reduction in patient radiation dose without an increase in success rate.

Sinus bradycardia, junctional rhythm, and low-rate atrial fibrillation in Short QT syndrome during 20 years of follow-up: three faces of the same genetic problem

We describe the case of an asymptomatic girl with sinus bradycardia and short QT interval at birth, junctional bradycardia in infancy requiring single-chamber pacemaker, atrial fibrillation in adolescence, and V141M mutation in the KCNQ1 gene. Atrial fibrillation recurred and became unresponsive to electrical or anti-arrhythmic therapy. During 20 years of follow-up, a progressive evolution from sinus node dysfunction to low-rate atrial fibrillation was observed.

Miniaturized Implantable Loop Recorder in Small Patients: An Effective Approach to the Evaluation of Subjects at Risk of Sudden Death

The etiological diagnosis of syncope and/or palpitations in children is often challenging. However, when noninvasive conventional examinations are inconclusive, the subcutaneous miniaturized implantable loop recorder (ILR) is recommended. The aim of our study was to evaluate the efficacy of miniaturized cardiac implantable devices in the early diagnosis of arrhythmias in children ≤6 years.

Results of remote follow-up and monitoring in young patients with cardiac implantable electronic devices.

BACKGROUND Remote monitoring is increasingly used in the follow-up of patients with cardiac implantable electronic devices. Data on paediatric populations are still lacking. The aim of our study was to follow-up young patients both in-hospital and remotely to enhance device surveillance. METHODS This is an observational registry collecting data on consecutive patients followed-up with the CareLink system. Inclusion criteria were a Medtronic device implanted and patients willingness to receive CareLink. Patients were stratified according to age and presence of congenital/structural heart defects (CHD). RESULTS A total of 221 patients with a device - 200 pacemakers, 19 implantable cardioverter defibrillators, and two loop recorders--were enrolled (median age of 17 years, range 1-40); 58% of patients were younger than 18 years of age and 73% had CHD. During a follow-up of 12 months (range 4-18), 1361 transmissions (8.9% unscheduled) were reviewed by technicians. Time for review was 6 ± 2 minutes (mean ± standard deviation). Missed transmissions were 10.1%. Events were documented in 45% of transmissions, with 2.7% yellow alerts and 0.6% red alerts sent by wireless devices. No significant differences were found in transmission results according to age or presence of CHD. Physicians reviewed 6.3% of transmissions, 29 patients were contacted by phone, and 12 patients underwent unscheduled in-hospital visits. The event recognition with remote monitoring occurred 76 days (range 16-150) earlier than the next scheduled in-office follow-up. CONCLUSIONS Remote follow-up/monitoring with the CareLink system is useful to enhance device surveillance in young patients. The majority of events were not clinically relevant, and the remaining led to timely management of problems.

Use of a Pediatric Syncope Unit Improves Diagnosis and Lowers Costs: A Hospital-Based Experience

Objectives To assess the effect of a dedicated pediatric syncope unit on the diagnostic and therapeutic management of children with suspected syncope. We also evaluated the effectiveness of the pediatric syncope unit model in decreasing unnecessary tests and hospitalizations, minimizing social costs, and improving diagnostic yield. Study design This single‐center cohort observational, prospective study enrolled 2278 consecutive children referred to Bambino Gesù Childrens Hospital from 2012 to 2017. Characteristics of the study population, number and type of admission examinations, and diagnostic findings before the pediatric syncope unit was implemented (2012‐2013) and after the pediatric syncope unit was implemented (2014‐2015 and 2016‐2017) were compared. Results The proportion of undefined syncope, number of unnecessary diagnostic tests performed, and number of hospital stay days decreased significantly (P < .0001), with an overall decrease in costs. A multivariable logistic regression analysis, adjusted for confounding variables (age, sex, number of diagnostic tests), the period after pediatric syncope unit (2016‐2017) resulted as the best independent predictor of effectiveness for a defined diagnosis of syncope (P < .0001). Conclusions Pediatric syncope unit organization with fast‐tracking access more appropriate diagnostic tests is effective in terms of accuracy of diagnostic yield and reduction of costs.

Radiofrequency catheter ablation of left-sided accessory pathways in children using a new fluoroscopy integrated 3D-mapping system

Introduction Advances in 3D electroanatomic-mapping technologies have resulted in a safe and effective profile of radiofrequency (RF) catheter ablation. The aim of this study was to evaluate a different catheter ablation approach in patients with left-sided accessory pathways (APs). Methods and results From January 2015 to December 2015, 30 patients (median age 11 years, median weight 45 kg) with manifest or concealed left-sided APs underwent RF catheter ablation with a new protocol. All procedures were performed with the CARTO UNIVU™ system, integrating electroanatomic maps with fluoroscopic views. A 7 Fr ablation catheter was inserted into the right femoral vein and advanced into the right atrium. Geometrical reconstruction and activation map of the right atrium, tricuspid annulus, and coronary sinus were acquired. The ablation catheter was then inserted into the left femoral artery and advanced through the aorta and aortic valve, creating an activation map of the mitral annulus. Catheter ablation was targeted to the site of the earliest activation. No complications occurred. The median procedure and fluoroscopy times were 130 min and 6 s, with a median fluoroscopy dose 0.5 mGy. An average of two catheters was used. Long-term success rate was 97% (29/30) at a median follow-up of 9.6 months. This approach reduced fluoroscopy time, dose and number of catheters used compared with manifest or concealed left-sided AP ablation using CARTO 3™ (P < 0.05). Conclusions This new ablation protocol seems to be promising in reducing fluoroscopy exposure and number of catheters used during left-sided AP ablation in children.

SYMPTOMATIC AND ASYMPTOMATIC CHILDREN WITH VENTRICULAR PREEXCITATION: SAME RISK FOR SUDDEN DEATH

Very recently, PACES/HRS Expert Consensus Statement on the Management of the Asymptomatic Young Patient with a WPW Electrocardiographic Pattern has been claimed that utilization of invasive risk stratification to assess the shortest preexcited R-R interval (SPERRI) in is reasonable in young patients