Transseptal puncture during catheter ablation associated with higher radiation exposure.

BACKGROUND: Electroanatomic mapping systems are increasingly used during ablations to decrease the need for fluoroscopy and therefore radiation exposure. For left-sided arrhythmias, transseptal puncture is a common procedure performed to gain access to the left side of the heart. We aimed to demonstrate the radiation exposure associated with transseptal puncture. METHODS: Data were retrospectively collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry. Patients with left-sided accessory pathway-mediated tachycardia, with a structurally normal heart, who had a transseptal puncture, and were under 22 years of age were included. Those with previous ablations, concurrent diagnostic or interventional catheterisation, and missing data for fluoroscopy use or procedural outcomes were excluded. Patients with a patent foramen ovale who did not have a transseptal puncture were selected as the control group using the same criteria. Procedural outcomes were compared between the two groups. RESULTS: There were 284 patients in the transseptal puncture group and 70 in the patent foramen ovale group. The transseptal puncture group had a significantly higher mean procedure time (158.8 versus 131.4 minutes, p = 0.002), rate of fluoroscopy use (38% versus 7%, p < 0.001), and mean fluoroscopy time (2.4 versus 0.6 minutes, p < 0.001). The acute success and complication rates were similar. CONCLUSIONS: Performing transseptal puncture remains a common reason to utilise fluoroscopy in the era of non-fluoroscopic ablation. Better tools are needed to make non-fluoroscopic transseptal puncture more feasible.

Utilising electroanatomic mapping during ablation in patients with CHD to reduce radiation exposure.

BACKGROUND: Patients with CHD can be exposed to high levels of cumulative ionising radiation. Utilisation of electroanatomic mapping during catheter ablation leads to reduced radiation exposure in the general population but has not been well studied in patients with CHD. This study evaluated the radiation sparing benefit of using three-dimensional mapping in patients with CHD. METHODS: Data were retrospectively collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy multi-institutional registry. Patients with CHD were selected. Those with previous ablations, concurrent diagnostic or interventional catheterisation and unknown arrhythmogenic foci were excluded. The control cohort was matched for operating physician, arrhythmia mechanism, arrhythmia location, weight and age. The procedure time, rate of fluoroscopy use, fluoroscopy time, procedural success, complications, and distribution of procedures per year were compared between the two groups. RESULTS: Fifty-six patients with congenital heart disease and 56 matched patients without CHD were included. The mean total procedure time was significantly higher in patients with CHD (212.6 versus 169.5 minutes, p = 0.003). Their median total fluoroscopy time was 4.4 minutes (compared to 1.8 minutes), and their rate of fluoroscopy use was 23% (compared to 13%). The acute success and minor complication rates were similar and no major complications occurred. CONCLUSIONS: With the use of electroanatomic mapping during catheter ablation, fluoroscopy use can be reduced in patients with CHD. The majority of patients with CHD received zero fluoroscopy.

Acute outcomes of three-dimensional mapping for fluoroscopy reduction in paediatric catheter ablation for supraventricular tachycardia.

BACKGROUND: Catheter ablation is a safe and effective therapy for the treatment of supraventricular tachycardia in children. Current improvements in technology have allowed progressive reduction in radiation exposure associated with the procedure. To assess the impact of three-dimensional mapping, we compared acute procedural results collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to published results from the Prospective Assessment after Pediatric Cardiac Ablation study. METHODS: Inclusion and exclusion criteria from the Prospective Assessment after Pediatric Cardiac Ablation study were used as guidelines to select patient data from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to compare acute procedural outcomes between cohorts. Outcomes assessed include procedural and fluoroscopy exposure times, success rates of procedure, and complications. RESULTS: In 786 ablation procedures, targeting 498 accessory pathways and 288 atrioventricular nodal reentrant tachycardia substrates, average procedural time (156.5 versus 206.7 minutes, p < 0.01), and fluoroscopy time (1.2 versus 38.3 minutes, p < 0.01) were significantly shorter in the study group. Success rates for the various substrates were similar except for manifest accessory pathways which had a significantly higher success rate in the study group (96.4% versus 93.0%, p < 0.01). Major complication rates were significantly lower in the study group (0.3% versus 1.6%, p < 0.01). CONCLUSIONS: In a large, multicentre study, three-dimensional systems show favourable improvements in clinical outcomes in children undergoing catheter ablation of supraventricular tachycardia compared to the traditional fluoroscopic approach. Further improvements are anticipated as technology advances.

Catheter ablation of left posterior fascicular ventricular tachycardia in children with limited fluoroscopy exposure.

INTRODUCTION: Catheter ablation of left posterior fascicular ventricular tachycardia in the pediatric population remains challenging, and most studies about this topic have been conducted on adult patients. This study aimed to assess the clinical presentation features and outcomes of catheter ablations performed using limited fluoroscopy with three-dimensional electroanatomic mapping system guidance in a pediatric left posterior fascicular ventricular tachycardia patient group. METHODS: A total of 20 consecutive patients undergoing left posterior fascicular ventricular tachycardia ablation at a single tertiary centre were enrolled. All children with left posterior fascicular ventricular tachycardia underwent electrophysiological studies using the EnSite NavX system guidance. Ablations were performed during the sinus rhythm based on the Purkinje potentials in all patients. RESULTS: The mean patient age was 12.7 years (range 2-16), and the mean patient weight was 51 kg (range 11-84). The mean procedure and median fluoroscopy times were 143.1 minutes and 3.4 minutes, respectively. No fluoroscopy was used in three patients. Acute success was achieved in 19 patients (95%). During a mean follow-up of 38.6 ± 19.35 months, left posterior fascicular ventricular tachycardia recurred in four patients (20%). Repeat ablations were performed successfully in those patients who developed recurrences. No complications were seen. CONCLUSIONS: Catheter ablation of left posterior fascicular ventricular tachycardia in children can be performed safely and effectively with low fluoroscopy exposure using a three-dimensional electroanatomic mapping system.

Long-term outcomes following cryoablation of atrioventricular nodal reentrant tachycardia in children.

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) is a common tachyarrhythmia substrate in children, which is successfully treated by catheter ablation using radiofrequency or cryothermal energy. In recent years, cryoablation (Cryo) using electroanatomical system guidance is more commonly preferred for use in children in order to decrease the risk of an atrioventricular block. However, there are concerns regarding the long-term efficacy of Cryo in treating AVNRT. We aimed to evaluate the feasibility, safety, and long-term efficacy of Cryo for AVNRT in children. METHODS AND RESULTS: A total of 275 consecutive children above 4 years of age diagnosed with AVNRT were included in our study. The EnSite system (St. Jude Medical, Inc., St. Paul, MN, USA) was used to reduce or eliminate fluoroscopy. The study included 275 patients (148 females, age: 11.9 ± 3.6 years) undergoing catheter ablation for AVNRT from July 2012 to September 2016. Acute success was obtained in all (100%) patients with a mean procedure time of 140 ± 44 minutes. Fluoroscopy was used in only 12 (4.4%) patients. During a follow-up time of 25.6 ± 13.5 months (median: 23 months), AVNRT recurred in 12 of 279 (4.4%) of the patients. Age, sex, number of Cryo lesions, and catheter tip size (6-mm vs 8-mm) were not predictive for recurrence. In nine patients, a repeat ablation was successfully performed with cryoenergy. CONCLUSIONS: Cryo for AVNRT is a safe and effective procedure with excellent long-term outcomes. The use of electroanatomical systems during ablation significantly decreases exposure to fluoroscopy without compromising success.

Comparison of 6-mm Versus 8-mm-Tip Cryoablation Catheter for the Treatment of Atrioventricular Nodal Reentrant Tachycardia in Children: A Prospective Study.

Due to its safety profile, cryoablation (Cryo) for atrioventricular nodal reentrant tachycardia (AVNRT) is more commonly preferred over radiofrequency (RF) ablation in children in recent years. Recent studies demonstrated high long-term success rates comparable to radiofrequency ablation. The aim of this prospective study was to compare the efficacy and safety of an 8-mm-tip versus 6-mm-tip Cryo catheter in the treatment of AVNRT in children. A total of 125 consecutive patients over 10 years of age with AVNRT were included. EnSite system (St. JudeMedical, St Paul, MN, USA) was used to reduce or eliminate fluoroscopy. The acute procedural success was 100% in both groups. The prodecure duration for the 8-mm-tip group was shorter (151.6 ± 63.2 vs. 126.6 ± 36.7 min, p < 0.01, respectively). Fluoroscopy was used in only 7 patients. The mean follow-up duration was 14.6 ± 8.4 months (median 13.5 months, min. 3 months and max. 27 months). The recurrence rate for AVNRT was also comparable between the two groups (6-mm tip: 9.6 vs. 8-mm tip: 8%). Cryo of AVNRT is a safe and effective procedure with comparable acute and mid-term follow-up success rates using 6-mm and 8-mm-tip catheters in children. In addition, procedure duration is shorter with an 8-mm-tip Cryo catheter.

Cryoablation with an 8-mm-Tip Catheter for Right-Sided Accessory Pathways in Children.

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.

Catheter ablation of idiopathic right ventricular arrhythmias in children with limited fluoroscopy.

INTRODUCTION: Definitive therapy of idiopathic right ventricular arrhythmias (VA) remains a challenge in interventional electrophysiology. The aim of this study was to evaluate the utility of EnSite Velocity system in the catheter ablation of RV tachycardia in children. METHODS: Thirty-five children with idiopathic right VA underwent catheter ablation procedure using the EnSite Velocity system guidance. RESULTS: The mean patient age was 12.0 ± 3.7 years and the mean patient weight was 43.6 ± 18.7 kg. The origin of right VA was divided into right ventricular outflow tract (RVOT) (30 patients) and other right ventricular localizations (five patients). The mean procedure and fluoroscopy times were 175 ± 67 min and 2.35 ± 1.89 min, respectively. No fluoroscopy was used in 19 patients. Acute success was achieved in 29 patients (83 %). The focus of VA was epicardial in three failed procedures. Cryocatheter (6-mm or 8-mm tip) was used in six patients, radiofrequency ablation (RFA) (4-mm or 8-mm tip) in 26 patients, and 4-mm tip irrigated RFA in three patients. During a mean follow-up of 15.9 ± 7.1 months, ventricular tachycardia recurred in six patients (20 %). There were three complications (transient atrioventricular block developed in one patient during parahissian cryoablation and two patients developed transient complete right bundle branch block). CONCLUSIONS: Catheter ablation of idiopathic right VA in children can be performed safely and effectively with limited fluoroscopy using the EnSite Velocity system.

The use of flecainide in critical neonates and infants with incessant supraventricular tachycardias.

OBJECTIVE: This study aimed to evaluate the efficacy of flecainide therapy in neonates and infants with drug resistant incessant supraventricular tachycardia. METHODS: The study included 11 neonates and infants who received medical and/or ablation therapy between January 2010 and December 2013. Mean patient age and weight were 101.6 ± 96 days and 5.3 ± 1.9 kg respectively. Of the 12 patients, 5 underwent ablation between January 2010 and December 2011, and 6 were treated medically between January 2012 and December 2013. Mean follow-up time was 18 months (6 months-4 years). RESULTS: The antiarrhythmic agent flecainide only became available in Turkey in 2012, and the most noteworthy point was its addition to the therapy administered prior to ablation (adenosine, esmolol-propranolol, propafenone, amiodarone and cardioversion). In all 6 patients admitted between January 2012 and December 2013, refractory SVT was successfully treated with the administration of a triple therapy regimen of esmolol-propranolol, amiodarone and flecainide. One patient with myocarditis developed an atrial flutter complicated by a concealed accessory pathway and was put on extracorporeal membrane oxygenation (ECMO) support due to cardiopulmonary failure. The SVT was terminated, but the patient died on the fifteenth day of ECMO support. One patient with recurrent tachycardia, who had previously undergone ablation for a complex cardiac anomaly and Wolf-Parkinson-White syndrome, was treated with ablation again. No recurrence of tachycardia was observed in any of the other 9 patients. CONCLUSION: It appears that the use of propranolol-esmolol and amiodarone combined with flecainide in the medical treatment of drug-resistant SVT may reduce the need for ablation in critical neonates and infants.

Implantation of looped epicardial cardioverter defibrillator coil on the surface of the right ventricular outflow tract.

BACKGROUND: We present the early results of looped epicardial cardioverter defibrillator coil implantation on the anterior surface of right ventricular outflow tract in infants and children. METHODS: Patients with a surgical history of an epicardial implantable cardioverter defibrillator system between 2013 and 2014 were included in the study. Patient age, gender, body weight, indications for a cardioverter defibrillator system implantation, defibrillation threshold values, and defibrillation therapies were retrospectively evaluated. RESULTS: There were eight patients with a mean age of 4.4 ± 2.9 years and a mean body weight of 19.5 ± 11.7 kg. Five of the patients had been diagnosed with long QT syndrome, one patient had been diagnosed with genetic channelopathy and noncompaction of the left ventricle, and two patients had been diagnosed with univentricle physiology. The implantable cardioverter defibrillator system was composed of pace-sense leads, an abdominal active can, and a defibrillation coil placed below the pulmonary valve annulus on the anterior surface of the heart. The mean defibrillation threshold was 6.6 ± 2.3 joules. There were four appropriate therapies in two patients in a mean follow-up of 9 ± 6.5 months. CONCLUSION: The significantly low defibrillation thresholds with the defibrillation coils located below the pulmonary valve annulus are encouraging. However, a larger patient series will be necessary to evaluate the safety and reliability of this technique.

Electroanatomic mapping guided cryoablation of Mahaim pathways in children with limited fluoroscopy exposure.

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.

Cryoablation of septal accessory pathways in children: midterm results.

BACKGROUND: Radiofrequency (RF) catheter ablation in the septal arrhythmia substrates has an increased risk of irreversible atrioventricular block. Despite its safety profile, several studies reported a lower acute success rate and a higher recurrence rate with cryoablation of septal accessory pathways (APs) when compared to RF ablation. The aim of this study was to assess the efficacy and safety of cryoablation of right septal APs using an electroanatomical mapping system guidance. METHODS AND RESULTS: A total of 43 consecutive patients (13.2 ± 5.5 years) underwent cryoablation for right septal APs. The EnSite system (St. Jude Medical, St. Paul, MN, USA) was used in all procedures. No fluoroscopy was used in 90% of patients (39/43). The mean fluoroscopy time in the remaining four patients was 3.7 ± 0.7 minutes. An electrophysiology catheter with 2-mm distal spacing was used to determine the precise AP location. The majority of the patients (20/43) had anteroseptal, and remaining of the patients had posteroseptal (15/43) and midseptal (8/43) APs. A 6-mm-tip catheter was used in 33 patients and 8-mm-tip catheter was used in nine patients (both catheters were used in one patient). The mean procedure duration and number of complete cryoablation lesions were 181.5 ± 60.6 minutes and 6.1 ± 3.1 minutes, respectively. Acute success was achieved in 40 of 43 patients (93%). No complications were noted. During a mean follow-up of 8.8 ± 4.8 months, five patients (12.5%) experienced recurrence. CONCLUSIONS: Our data suggest that cryoablation of septal APs can be performed safely with comparable efficacy to the reported RF ablation results using a limited fluoroscopy approach.

Assessment of atrioventricular conduction following cryoablation of atrioventricular nodal reentrant tachycardia in children.

BACKGROUND: Early-onset transient atrioventricular block (AVB) is a rare occurrence following cryoablation of atrioventricular nodal reentrant tachycardia (AVNRT), despite lack of any AVB at the end of the procedure. The purpose of this prospective study was to assess AVB shortly after successful cryoablation of AVNRT in children. METHODS: A 6-mm-tip cryocatheter was used in 39 procedures. An 8-mm-tip catheter was used in 11 procedures. Twelve-lead electrocardiograms (ECGs) and 24-hour ambulatory ECGs were performed 24 hours prior to the procedure and immediately following the procedure. All procedures were done using the EnSite system (St. Jude Medical, St. Paul, MN, USA) without fluoroscopy. RESULTS: Although nine (18%) patients developed variable degrees of transient AVB during the procedure, all of them had normal atrioventricular (AV) conduction at the end of the procedure and did not require any intervention. Four of these patients had variable degrees of transient AVB following the procedure despite having normal AV conduction at the end of the procedure. One developed Mobitz type I AVB, which lasted for 11.5 hours, and the other three experienced 2:1 AVB, which lasted for 2, 8, and 24 hours, respectively. All patients had complete resolution of the AVB, which was also documented with the 24-hour ambulatory ECGs after the procedure. CONCLUSION: Early transient AVB can develop following AVNRT cryoablation even if AV conduction is normal at the end of the procedure. Despite the transient AVB in the initial 24 hours after the procedure in some cases, there is no evidence for ongoing AV nodal dysfunction.

Catheter ablation of idiopathic ventricular tachycardia in children using the EnSite NavX system with/without fluoroscopy.

OBJECTIVES: Curative therapy of idiopathic ventricular tachycardia remains a challenge in interventional electrophysiology. The aim of this study was to demonstrate the utility of an EnSite NavX system in the catheter ablation of idiopathic ventricular tachycardia in children. PATIENTS AND METHODS: In all, 17 children with idiopathic ventricular tachycardia underwent electrophysiological studies using the EnSite NavX system guidance. RESULTS: The mean patient age was 13 ± 2.4 years (range: 7.8-17.9) and the mean patient weight was 52.3 ± 11.9 kg (range: 32-75). The origin of ventricular tachycardia was in the right ventricular outflow tract in nine patients, in the left ventricle in six, near the bundle of His/right bundle branch in one, and in the left aortic cusp in one. The mean procedure and fluoroscopy times were 169.3 ± 43.2 minutes and 8 ± 10.8 minutes, respectively. No fluoroscopy was used in six patients. The mean radiation exposure was 33.1 ± 56.4 mGy. Acute success was achieved in 14 patients (82%). The focus of ventricular tachycardia was epicardial in two failed procedures. During a mean follow-up of 8.5 ± 7.6 months, ventricular tachycardia recurred in three patients, two of whom underwent a second procedure. Except for one patient who developed transient right bundle branch block, no complications were seen. CONCLUSION: Catheter ablation of idiopathic ventricular tachycardia in children can be performed safely and effectively with low fluoroscopy exposure using the EnSite NavX system.

Catheter ablation of drug resistant supraventricular tachycardia in neonates and infants.

BACKGROUND: The aim of this study was to evaluate the indications, results and complications of radiofrequency ablation (RFA) and transcatheter cryoablation (TCA) in neonates and infants with incessant drug-resistant supraventricular tachycardia (SVT). METHODS: Out of 225 patients who underwent RFA and TCA at our center between January2010 and February 2012, 5 patients under the age of 1 (4 male, 1 female) were evaluated. The indication for RFA/TCA was recurrent hemodynamically compromising drug-resistant SVT. RESULTS: Over a 2-year period, 6 ablation procedures were performed in 5 patients. Average patient age was 3.3 ± 3.9 months (12 days - 9.5 months); average patient weight was 5.4 ± 2.2 kg (3.5-9 kg). One patient had ventricular septal defect, 1 had corrected transposition of great arteries, ventricular septal defect, right ventricular hypoplasia and pulmonary hypertension, while 3 had only patent foramen ovale. Electrophysiology study showed 1 accessory pathway in each patient (right posteroseptal in 2, left posteroseptal in 2 and left lateral in 1). The pathway was manifest in 1 patient with Wolff-Parkinson-White syndrome (WPW) and concealed in the rest. Two of the concealed pathways had slow conduction time and decremental properties (the permanent form of junctional reciprocating tachycardia). Two patients underwentTCA and 3 - RFA, with an acute success rate of 100%. In the first week after the procedure, the patient with the complex cardiac anomaly and WPW developed recurrence and under went ablation again. Four of the procedures were carried out using an electroanatomic mapping system besides fluoroscopy. Average procedure time was 167 min (100-234); fluoroscopy time was 8.2 min (0.7-19.7). None of the patients developed major complications. After the average follow-upperiod of 6.5 months (3-18), all patients were symptom-free without medication. CONCLUSIONS: RFA and TCA can be performed successfully in neonates and infants within cessant medically refractory SVT.

Subxiphoid approach to epicardial implantation of implantable cardioverter defibrillators in children.

BACKGROUND: Epicardial implantation of implantable cardioverter defibrillators (ICDs) is considered in the presence of intracardiac shunt, venous access issue, or small body size. We report our experience with epicardial ICD coil implantation using a minimally invasive method. METHODS: Nine patients who underwent epicardial ICD implantation were included. The median age was 7.4 years (3.9-9.6 years) and the median weight was 15 kg (12-24 kg). Diagnosis at the time of implantation included long QT syndrome (n = 5), catecholaminergic polymorphic ventricular tachycardia (n = 2), hypertrophic cardiomyopathy (n = 1), and fast monomorphic ventricular tachycardia (n = 1). The minimally invasive method involved a subxiphoid incision to place the epicardial pacing leads. The ICD coil was placed in the transverse sinus in four patients using an access path posterior to the heart. The second approach involved a path anterior to the heart to reach the epicardial location posterior to the left atrial appendage in the five remaining patients. No fluoroscopy was used in either approach. The median defibrillation threshold (DFT) at implantation was 7.5 J. RESULTS: Lower DFTs were observed in the anterior approach (10 J vs 5 J). Appropriate ICD shocks were observed in three patients during the median 18-month follow-up period (0.3-28 months). No inappropriate shocks were noted. One patient developed pericardial tamponade 39 days after the procedure and was surgically drained. CONCLUSIONS: Minimally invasive epicardial ICD coil implantation in children with low DFT values is possible. The anterior implantation approach appears superior to the posterior approach.

Intrathoracic implantation of a dual-chamber pacemaker in a preterm infant with congenital AV block.

Congenital complete atrioventricular block can be concomitant with congenital heart diseases or maternal connective tissue disorders like systemic lupus erythematosus and Sjögren's syndrome. Such patients may require implantation of a permanent pacemaker due to ventricular dysfunction. While many methods of pacemaker implantation have been tested, one that is optimal for low birth weight infants remains to be determined. We present a preterm infant with maternal Sjögren's syndrome with congenital heart block and describe the technique for implantation of an intrathoracic dual-chamber pacemaker.

Successful cryoablation of atrioventricular nodal reentrant tachycardia and coexisting accessory pathways without fluoroscopy.

We report the case of a 14-year-old boy patient admitted to our outpatient clinic with palpitations and documented supraventricular tachycardia. Electrophysiological study and ablation were planned. In the electrophysiological study, two tachycardias with different cycle lengths and morphologies were induced. After elimination of the slow pathway, left posterior accessory pathway was detected and successfully ablated. Another pathway was detected following that ablation. Due to the slow retrograde conduction of this pathway, diltiazem infusion was started to uncover the accessory pathway. The second accessory pathway was at the left posteroseptal region and was successfully ablated. After a 30-minute waiting period, no tachycardia was induced. In addition, no fluoroscopy was used during the procedure.

Cryoablation of ventricular tachycardia arising from the left-coronary sinus cusp.

Ventricular tachycardia (VT) arising from the coronary sinus cusps and mimicking right-ventricular morphology is a rare entity. In this report, we report the successful cryoablation of left-coronary sinus cusp VT.