An integrated approach to radiofrequency ablation of para-Hisian accessory pathways in paediatric patients.

Masquerade: An unusual accessory pathway with ventricular insertion at the right–left sinus of Valsalva mimicking outflow tract ventricular tachycardia

BackgroundTo compare the safety, effectiveness, electrophysiological characteristics, and mechanisms of different approaches for the ablation of para-Hisian accessory pathways (APs).MethodEighteen consecutive patients with para-Hisian APs were enrolled in this study. Detailed mapping of retrograde conduction as well as antegrade conduction (if possible) in both the right sided His bundle region and non-coronary cusp (NCC) region was performed before ablation. Ten patients underwent initial ablation in the right septal (RS) region while the remaining 8 patients were ablated in NCC region. Repeat ablation was attempted in an alternative region if ablation at the first site failed.ResultsAmong the patients whose procedures were successful, 7 cases were successfully ablated with a NCC approach while 10 were conventionally ablated in RS region. For successful procedures targeting the NCC region, the earliest atrial activation (EAA) in NCC region preceded that at RS region by 4–13 ms. The distance between NCC targets and near-field His potential (NFH) points was longer than that between RS targets and NFH points. Additionally, the risk of complication after ablation in NCC region was lower compared with that following RS-targeted procedure.ConclusionNCC approach provided a high success rate and low risk of complication for the ablation of para-Hisian APs as long as EAA was observed in NCC region. Sites of successful para-Hisian AP ablation in NCC region had different retrograde mapping patterns in comparison with successful ablation sites in the RS region.

PO-04-109 OUTCOMES OF RADIOFREQUENCY CATHETER ABLATION OF DISTINCT ANTERO-SEPTAL ACCESSORY PATHWAYS BY CONVENTIONAL ELECTROPHYSIOLOGICAL MAPPING

Catheter ablation of para-Hisian accessory pathways (APs) can be challenging because of adjacent conduction tissue. Some different approaches for ablation, including the inferior vena cava approach (IVC-A), the noncoronary cusp approach (NCC-A), or the superior vena cava approach (SVC-A), have been reported. However, when should para-Hisian APs be mapped and ablated by the IVC-A, NCC-A, or SVC-A is not well established. This study included 55 consecutive patients (mean age, 53±11 years, 36 males) with para-Hisian APs. On the basis of the approach resulting in successful ablation, patients were divided into IVC-A, NCC-A, and SVC-A groups. The clinical characteristics, surface ECG, intracardiac electrogram findings, and response to ablation were analyzed. Para-Hisian APs were eliminated by IVC-A in 48 of the 55 (87%) patients. The rates of para-Hisian APs requiring NCC-A (4/55 patients, 7%) and SVC-A (3/55 patients, 6%) were relatively low. During mapping at the para-Hisian region, the local ventricular and atrial potentials were well fused during retrograde AP conduction in 45 of the 48 patients in IVC-A group, 0 of the 4 patients in NCC-A group, and 1 of the 3 patients in SVC-A group, respectively. There was no significant difference in the preexcitation characteristics among the 3 groups. Most para-Hisian APs can be safely and effectively ablated by IVC-A, and ablation in the NCC is not an initial or a preferred approach. The degree of local ventriculoatrial fusion in the para-Hisian region during retrograde AP conduction can differentiate or predict the successful ablation site.

Background: Ablation of para-hisian accessory pathways (APs) remains challenging due to anatomic characteristics, and a few studies have focused on the causes for recurrence of radiofrequency ablation of para-hisian APs.Objective: This retrospective single center study aimed to explore the risk factors for recurrence of para-hisian APs.Methods: One hundred thirteen patients who had para-hisian AP with an acute success were enrolled in the study. In the 6-year follow-up, 15 cases had a recurrent para-hisian AP. Therefore, 98 patients were classified into the success group, while 15 patients were classified into the recurrence group. Demographic and ablation characteristics were analyzed.Results: Gender difference was similar in two groups. The median age was 36.2 years old and was younger in the recurrence group. Maximum ablation power was significantly higher in the success group (29 ± 7.5 vs. 22.9 ± 7.8, p < 0.01). Ablation time of final target sites was found to be markedly higher in the success group (123.4 ± 53.1 vs. 86.7 ± 58.3, p < 0.05). Ablation time <60 s was detected in 12 (12.2%) cases in the success group and 7 (46.7%) cases in the recurrence group (p < 0.01). Occurrence of junctional rhythm was significantly higher in the recurrence group (25.5% vs. 53.3%, p < 0.05). No severe conduction block, no pacemaker implantation, and no stroke were reported. Junctional rhythm during ablation (OR = 3.833, 95% CI 1.083–13.572, p = 0.037) and ablation time <60 s (OR = 5.487, 95% CI 1.411–21.340, p = 0.014) were independent risk factors for the recurrence of para-hisian AP.Conclusions: With careful and accurate mapping, it is relatively safe to ablate para-hisian AP. If possible, proper extension of ablation time could reduce the recurrence rate of para-hisian APs.

P4-112: Successful ablation of a concealed parahisian accessory pathway using remote control magnetic navigation following failure of conventional methods

Radiofrequency (RF) catheter ablation of para-Hisian accessory pathways (APs) can be challenging due to proximity to the conduction system. A total of 30 consecutive patients with para-Hisian AP were enrolled for ablation in three centers, 12 (40%) of whom had previously failed attempted ablation from the inferior vena cava (IVC) approach. Ablation was preferentially performed using a superior approach from the superior vena cava (SVC) in all patients. The para-Hisian AP was eliminated from the SVC approach in 28 of 30 (93.3%) patients. In the remaining two patients, additional ablation from IVC was required to successfully eliminate the AP. There were two patients experienced reversible complete atrial-ventricular block and PR prolongation during the first RF application. Long-term freedom from recurrent arrhythmia was achieved in 29 (96.7%) patients over a mean follow-up duration of 15.6 ± 4.6 months. Catheter ablation of para-Hisian AP from above using a direct SVC approach is both safe and effective, and should be considered especially in patients who have failed conventional ablation attempts from IVC approach.

Cryotherapy ablation of parahisian accessory pathways in children.

Funding Acknowledgements Type of funding sources: None. Background Ablation of para-hisian accessory pathways (APs) remains challenging due to anatomic characteristics and few studies have focused on the causes for recurrence of radiofrequency ablation of para-hisian APs. Objective This retrospective single center study was aimed to explore the risk factors for recurrence of para-hisian APs. Methods 113 patients who had a para-hisian AP with an acute success were enrolled in the study. In the 11-year follow-up, 15 cases had a recurrent para-hisian AP. Therefore 98 patients were classified into success group while 15 patients were classified into recurrence group. Demographic and ablation characteristics were analyzed. Results Gender difference was similar in two groups. The median age was 36.2 years old and was younger in recurrence group. Maximum ablation power was significantly higher in success group (29 ± 7.5 vs 22.9 ± 7.8, p &amp;lt; 0.01). Ablation time of final target sites was found to be markedly higher in success group (123.4 ± 53.1 vs 86.7 ± 58.3, p &amp;lt; 0.05). Ablation time less than 60 seconds was detected in 12 (12.2%) cases in success group and 7 (46.7%) cases in recurrence group (p &amp;lt; 0.01). Occurrence of junctional rhythm was significantly higher in recurrence group (25.5% vs 53.3%, p &amp;lt; 0.05). No severe conduction block, no pacemaker implantation and no stroke were reported. Junctional rhythm during ablation (OR = 3.833, 95%CI 1.083-13.572, p = 0.037) and ablation time &amp;lt;60s (OR = 5.487, 95%CI 1.411-21.340, p = 0.014) were independent risk factors for the recurrence of para-hisian AP. Conclusions Considering the long-term safety of ablation of para-hisian AP, proper extension of ablation time and increase of ablation power could be applied during operation.

Radiofrequency catheter ablation of parahisian accessory pathways in pre-excitation syndrome is a challenging task, due to the extremely high risk of complete atrioventricular block. In this brief report we describe the case of a 32 year-old man presenting a parahisian accessory pathway, who has been successfully treated by radiofrequency ablation. Radiofrequency catheter ablation using low-power radiofrequency current is considered to be the most appropiate method of ablation in adult patients.

Supravalvar ablation has now been well documented to be the ideal mode for ablating specific forms of ventricular tachycardia, atrial tachycardia, and accessory pathways. A studied appreciation of the anatomy of the supravalvar region is a prerequisite for electrophysiologists to safely and effectively approach these arrhythmias. In addition, the consistent ability to correlate the recorded electrograms with fluoroscopic anatomy and intracardiac ultrasound images enhances the chance of successful elimination of supravalvar arrhythmias.

Syndrome de Wolff-Parkinson-White avec voie accessoire parahisienne : la cryoablation au cœur de la prise en charge

Purpose : Radiofrequency catheter ablation (RFCA) has become an effective therapeutic modality for treating pediatric tachyarrhythmias. Using conventional RFCA catheters, ablation of parahisian accessory pathways may be difficult and have high risk for heart block. We reviewed the efficacy and complications of the RFCA in children and adolescent with arrhythmias including parahisian accessory pathways. Methods : We studied 48 patients (aged 2 years to 20 years) who had undergone RFCA from August 2003 to March 2007. We reviewed clinical findings, electrophysiologic studies, RFCA data, complications, and follow-up results of the patients. Results : Mean age of the patients was 13.1 years. Numbers and types of arrhythmias (age, acute success rate) were as follows: 19 WPW syndrome including 5 parahisian accessory pathways (13.7±4.6 yr, 18/19), 11 atrioventricular reentrant tachycardia with concealed bypass tract (12.3±5.0 yr, 10/11), 13 atrioventricular nodal reentrant tachycardia (12.6±4.4 yr, 13/13), 4 atrial flutter (13.0±7.4 yr, 3/4), and 1 ventricular tachycardia (20 yr, 1/1). Associated cardiac structural lesion was not detected in 48 patients. The recurrence rate was 6.5%, and the final success rate was 93.8%. Conclusion : These results suggest that RFCA is a highly effective treatment method in children and adolescent with tachyarrhythmia.

&lt;sec&gt;&lt;st&gt;Objective&lt;/st&gt; Catheter ablation of anteroseptal atrioventricular (AV) accessory pathway (AP) is still challenging because of their proximity to the normal AV conduction system that may be damaged with ablation. Traditionally, catheter ablation of anteroseptal APs via the inferior vena cava approach. In a few cases, anteroseptal AP ablation may fail because of conservative energy delivery at these sites or anatomical factor. In the recent years, a few cases of successful anteroseptal AP ablation in the noncoronary cusp (NCC) or sub tricuspid annulus have been reported. However, when need to map and ablate from the NCC or sub tricuspid annulus in patients with anteroseptal APs and what will be the mapping results at the NCC in patients with anteroseptal APs successful ablated in the, right anteroseptal region (RAS) have not been well evaluated. The purpose of this study was to discuss the characteristics of surface ECG, anatomic consideration, electrophysiology, and the strategy of ablation of anteroseptal APs in order to increase the success rate and safety of radiofrequency catheter ablation. &lt;/sec&gt; &lt;sec&gt;&lt;st&gt;Methods&lt;/st&gt; There were 55 consecutive patients (age 53 ± 11 years, 36 male) out of 2200 patients presenting with anteroseptal APs who underwent RF ablation at our centre between July 2006 and March 2013. On the basis of successful ablation location, these patients were divided into right anteroseptal region group (RAS group, through inferior vena cava approach), noncoronary cusp group (NCC group, through retrograde aorta approach) and sub tricuspid annulus group (Sub-TA group, throngh superior vena cava approach). The clinical characteristics, surface electrocardiogram (ECG), intracardiac electrogram findings, and response to ablation in these patients between three groups were analysed. The strategies for mapping and ablation of anteroseptal APs were discussed. &lt;/sec&gt; &lt;sec&gt;&lt;st&gt;Results&lt;/st&gt; Successful ablation were achieved in all the 55 patients with anteroseptal APs. The sites with successful ablation were located in the RAS, adjacent to the His bundle region, in 48 patients including in 9 patients whose initial ablation were unsuccessful in the NCC. In the 4 cases with successful ablation in the NCC, the initial attempt ablation in the NCC without trying in the RAS was performed in 1 cases in whom the decision to target the NCC was based on previous experience of V-A fusion pattern adjacent to the His bundle region suggestive of an NCC AP site. In 1 of the 4 patients, irrigated energy (30–40 W and infusion rate of 17–30 ml/min) was used to eliminated the AP in the NCC after failed ablation with non-irrigated energy. There were 3 cases underwent successful ablation at Sub-TA region by a superior approach from the right internal jugular vein. There were no important complications during perioperative period. All the patients underwent a period of 8 months to 7 years of follow-up by telephone or outpatient department. Four patents ablated in RAS region recurred. No recurrence in patients underwent successful ablation in NCC or Sub-TA region. &lt;/sec&gt; &lt;sec&gt;&lt;st&gt;Conclusions&lt;/st&gt; The results of catheter ablation of anteroseptal APs in a large case series indicate that anteroseptal APs in most patients can be successful ablated in RAS region, but in a few patients, anteroseptal APs need to be ablated from the NCC or Sub-TA region. The pre-excitation characteristics have no meaningful differences among the RAS, NCC and Sub-TA group. The incidence of anteroseptal AP which had to be ablated from NCC is relatively low, so ablation from NCC was not a preferential approach. The VA fusion pattern in RAS during retrograde AP conduction may be helpful to differentiate or predict successful ablation from RAS, NCC or Sub-TA in most patients with anteroseptal AP. &lt;/sec&gt;

Catheter ablation of the parahisian accessory pathways (PHAP) has been established as the definitive therapy for this type of arrhythmia. However, the PHAP proximity to the normal atrioventricular conduction system makes the procedure technically challenging. Here, we have reported a case series of 20 patients with PHAP who underwent aortic access ablation to evaluate the safety and efficacy of this approach in the PHAP ablation. The ablation through the aortic cusps was the successful approach in 13 of 20 (65%) of the cases. In 11 patients, the aortic approach was the initial strategy for ablation, and the accessory pathway was eliminated in seven (63.6%) of them. The aortic approach followed a failed right-sided attempt in nine patients. In six (66.7%) patients, the ablation was successful with the aortic approach. The only independent predictor for the successful ablation with each approach was the earliest ventricular activation before delta wave (predelta time) and a right-sided earliest ventricular activation of more than 23 ms had high sensitivity and specificity for right-sided success. Systematically using the two strategies (right and left approaches), the ablation of the PHAP was successful in 18 (90%) patients. The aortic approach seems to be a safe and effective strategy for the ablation of PHAP. It can be used when the right-sided approach fails or even considered as an initial strategy when the predelta time is less than 23 ms in the right septal region. When combining the right- and left-sided approaches, the success rate is high. We believe that the retrograde aortic approach remains a key tool for this challenging ablation.