Successful Accessory Pathway Ablation Research Articles

Fluoroscopy integration module reduces radiation exposure without affecting procedure time in accessory pathway ablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Conventional Accessory Pathway (AP) ablation is a straightforward approach with high success rates, but the fluoroscopy time is significantly higher. Electroanatomical mapping systems (EMS), reduce the fluoroscopy time, but anatomical reconstruction and activation mapping prolong the procedure time. The Fluoroscopy Integration Module (FIM) uses prerecorded fluoroscopy images and allows ablation similar to conventional technique without creating an anatomical map. In this study, we investigated the effects of combining the FIM with the traditional technique on procedure time, success, and radiation exposure. Methods 112 patients who underwent AP ablation were included in our study. In 18 patients, right and left anterior oblique (RAO -LAO) images were recorded after the insertion of the catheters and integrated with FIM. Afterwards, ablation was performed similarly to the conventional technique but without using fluoroscopy. To accelerate the procedure anatomical and activation maps were not created. Contact-force catheters were not used. 94 patients were ablated conventionally using only fluoroscopy. Results Combining the FIM with the conventional method significantly reduced radiation exposure (Fluoroscopy time: 3,3±2,6 vs 11,5±11,6 sec, p: 0,001; Dose-area-product (DAP): 7,3±6,2 vs. 28,6±40,5 μGym2, p: 0,003) without affecting the total procedure time ( 64,4±15 vs. 62,6±28,7 sec, p: 0,272 ), time to successful ablation ( 33,2±13,9 vs. 29,7±29,5 sec p: 0,056) and radiofrequency application time ( 183,7±94,4 vs. 167,3±89,8 sec p: 0,336). Conclusion These findings suggest that FIM can be used for rapid and successful ablation of APs with reduced radiation exposure times.

Effect of pulmonary vein isolation on atrial fibrillation recurrence after accessory pathway ablation in patients with Wolff-Parkinson-White syndrome.

BackgroundAlthough successful ablation of the accessory pathway (AP) eliminates atrial fibrillation (AF) in some of patients with Wolff‐Parkinson‐White (WPW) syndrome and paroxysmal AF, in other patients it can recur.HypothesisWhether adding pulmonary vein isolation (PVI) after successful AP ablation effectively prevents AF recurrence in patients with WPW syndrome is unknown.MethodsWe retrospectively studied 160 patients (102 men, 58 women; mean age, 46 ± 14 years) with WPW syndrome and paroxysmal AF who underwent AP ablation, namely 103 (64.4%) undergoing only AP ablation (AP group) and 57 (35.6%) undergoing AP ablation plus PVI (AP + PVI group). Advanced interatrial block (IAB) was defined as a P‐wave duration of >120 ms and biphasic (±) morphology in the inferior leads, using 12‐lead electrocardiography (ECG).ResultsDuring the mean follow‐up period of 30.9 ± 9.2 months (range, 3‐36 months), 22 patients (13.8%) developed AF recurrence. The recurrence rate did not differ in patients in the AP + PVI group and AP group (15.5% vs 10.5%, respectively; P = .373). Univariable and multivariable Cox regression analyses showed that PVI was not associated with the risk of AF recurrence (hazard ratio, 0.66; 95% confidence interval, 0.26‐1.68; P = .380). In WPW patients with advanced IAB, the recurrence rate was lower in patients in the AP + PVI group vs the AP group (90% vs 33.3%, respectively; P = .032).ConclusionsPVI after successful AP ablation significantly reduced the AF recurrence rate in WPW patients with advanced IAB. Screening of a resting 12‐lead ECG immediately after AP ablation helps identify patients in whom PVI is beneficial.

Advanced interatrial block predicts recurrence of atrial fibrillation after accessory pathway ablation in patients with Wolff-Parkinson-White syndrome.

BackgroundParoxysmal atrial fibrillation (AF) frequently occurs in patients with Wolff‐Parkinson‐White (WPW) syndrome. Although successful ablation of the accessory pathway (AP) eliminates paroxysmal AF in some patients, in other patients it can recur.HypothesisWe investigated the clinical utility of advanced interatrial block (IAB) for predicting the risk of AF recurrence in patients with verified paroxysmal AF and WPW syndrome after successful AP ablation.MethodsThis retrospective study included 103 patients (70 men, 33 women; mean age, 44 ± 16 years) with WPW syndrome who had paroxysmal AF. A resting 12‐lead electrocardiogram was performed immediately after successful AP ablation to evaluate the presence of advanced IAB, which was defined as a P‐wave duration of >120 ms and biphasic [±] morphology in the inferior leads.ResultsDuring the mean follow‐up period of 30.9 ± 20.0 months (range, 2‐71 months), 16 patients (15.5%) developed AF recurrence. Patients with advanced IAB had significantly reduced event‐free survival from AF (P < .001). Cox regression analysis with adjustment for the left atrial diameter and CHA2DS2‐VASc score identified advanced IAB (hazard ratio, 9.18; 95% confidence interval [CI], 2.30‐36.72; P = .002) and age > 50 years (hazard ratio, 12.64; 95% CI, 1.33‐119.75; P = .027) as independent predictors of AF recurrence.ConclusionsAdvanced IAB was an independent predictor of AF recurrence after successful AP ablation in patients with WPW syndrome.

Comparison of the Accuracy of Three Algorithms in Predicting Accessory Pathways among Adult Wolff-Parkinson-White (WPW) Syndrome Patients in our Population

Background: after the introduction of catheter ablation of atrioventricular accessory pathways (APs) in Wolff-Parkinson-White (WPW) syndrome, to facilitate planned ablation and minimize catheter-related injury, predicting the AP was required. Localization of APs can be anywhere around the atrioventricular (AV) annuli, left- or right-sided, or within the septum or a rare possibility of Mahaim fibers. Objective: to compare between three algorithms in their accuracy in predicting the exact site of accessory pathway. Patients and Methods: one hundred patients with manifest pre-excitation who underwent electrophysiological study (EPS) and successful ablation of accessory pathway who were subjected to history taking, complete physical examination stressing on 12-lead of pre-excited electrocardiogram (ECG). Results: the distributions of the accessory pathway with left lateral accessory pathway being the most prevalent (27%) while the postero-lateral being the least prevalent one (2%) and that Right-sided accessory pathway was most frequently predicted by Arruda algorithm in 31% of patients and least frequently predicted by D’Avila in 17% of patients while its actually present in 23% of patients according to the EP study, Left-sided accessory pathway was most frequently predicted by D’Avila (61%) and least frequently predicted by Arruda (49%) whereas it was truly present in 51% of patients according to EP study. Mid and antero-septal accessory pathways were most frequently predicted by Chiang and least frequently predicted by Arruda while it was present in 26% of cases proved by EP study. In all algorithms, 72 % of predictions were correct for Chiang, 81 % for D’Avila, and 71 % for Arruda and the percentage of predictive accuracy of all algorithms did not differ between the algorithms (p=1.000; p=0.076; p=0.064, respectively) The best algorithm for prediction of right-sided and left-sided accessory pathways was D’Avila (p<0.001). The best algorithm that is particularly useful in predicting antero-septal and mid-septal accessory pathways was Chiang (p<0.001). Conclusion: prior knowledge of the AP location allows better planning, faster and safer procedure, as well as decreased exposure to ionizing radiation and unnecessary punctures. In all algorithms, 72% of predictions were correct for Chiang, 81% for D'Avila, and 71% for Arruda and the percentage of predictive accuracy of all algorithms did not differ between the algorithms (p=1.000; p=0.076; p=0.064, respectively). The best algorithm for prediction of right-sided and left-sided accessory pathways was D'Avila (p<0.001). The best algorithm that is particularly useful in predicting anteroseptal and mid-septal accessory pathways was Chiang (p<0.001).

Comparison of the Accuracy of Three Algorithms in Predicting Accessory Pathways among Adult Wolff-Parkinson-White (WPW) Syndrome Patients in our Population

Background: after the introduction of catheter ablation of atrioventricular accessory pathways (APs) in Wolff-Parkinson-White (WPW) syndrome, to facilitate planned ablation and minimize catheter-related injury, predicting the AP was required. Localization of APs can be anywhere around the atrioventricular (AV) annuli, left- or right-sided, or within the septum or a rare possibility of Mahaim fibers. Objective: to compare between three algorithms in their accuracy in predicting the exact site of accessory pathway. Patients and Methods: one hundred patients with manifest pre-excitation who underwent electrophysiological study (EPS) and successful ablation of accessory pathway who were subjected to history taking, complete physical examination stressing on 12-lead of pre-excited electrocardiogram (ECG). Results: the distributions of the accessory pathway with left lateral accessory pathway being the most prevalent (27%) while the postero-lateral being the least prevalent one (2%) and that Right-sided accessory pathway was most frequently predicted by Arruda algorithm in 31% of patients and least frequently predicted by D’Avila in 17% of patients while its actually present in 23% of patients according to the EP study, Left-sided accessory pathway was most frequently predicted by D’Avila (61%) and least frequently predicted by Arruda (49%) whereas it was truly present in 51% of patients according to EP study. Mid and antero-septal accessory pathways were most frequently predicted by Chiang and least frequently predicted by Arruda while it was present in 26% of cases proved by EP study. In all algorithms, 72 % of predictions were correct for Chiang, 81 % for D’Avila, and 71 % for Arruda and the percentage of predictive accuracy of all algorithms did not differ between the algorithms (p=1.000; p=0.076; p=0.064, respectively) The best algorithm for prediction of right-sided and left-sided accessory pathways was D’Avila (p<0.001). The best algorithm that is particularly useful in predicting antero-septal and mid-septal accessory pathways was Chiang (p<0.001). Conclusion: prior knowledge of the AP location allows better planning, faster and safer procedure, as well as decreased exposure to ionizing radiation and unnecessary punctures. In all algorithms, 72% of predictions were correct for Chiang, 81% for D'Avila, and 71% for Arruda and the percentage of predictive accuracy of all algorithms did not differ between the algorithms (p=1.000; p=0.076; p=0.064, respectively). The best algorithm for prediction of right-sided and left-sided accessory pathways was D'Avila (p<0.001). The best algorithm that is particularly useful in predicting anteroseptal and mid-septal accessory pathways was Chiang (p<0.001).

Supraventricular tachyarrhythmias in patients with a persistent left superior vena cava.

A persistent left superior vena cava (PLSVC) is the most common thoracic venous anomaly. This venous anomaly can impact the evaluation and treatment of supraventricular tachyarrhythmia (SVA). The aim of this study was to assess the proportion and characteristics of PLSVC in adult SVA patients. From July 2002 to July 2012, clinical and procedural data from databases of 10 cardiac electrophysiology laboratories in the Yeungnam region of the Republic of Korea were reviewed. Of 6662 adult SVA patients who underwent an EP study or catheter ablation of SVA during the 10-year study period, 18 patients had PLSVC (mean age 47.6 ± 14.8 years, 10 men). The proportion of PLSVC in adult SVA patients was 0.27% (18/6662). SVA type and procedural outcomes of radiofrequency (RF) catheter ablation in these patients were investigated and the results were as follows: successful slow pathway modification in six of seven patients with atrioventricular nodal reentrant tachycardia (AVNRT), successful ablation of accessory pathway in three of four patients with atrioventricular reentrant tachycardia, and successful ablation of atrial tachycardia (cavotricuspid isthmus-dependent in two, septal macroreentry in one, focal from the PLSVC in one) in three of four patients. In one patient with junctional tachycardia, catheter ablation failed. In two patients with atrial fibrillation, catheter ablation was successful. Among adult SVA patients who underwent an EP study or RF catheter ablation during the 10-year study period, 0.27% had PLSVC. The most common type of SVA was AVNRT. The success rate of catheter ablation was 82% in SVA patients with PLSVC. There were no procedure-related complications.

Frequency of fractionated ventricular activation and atrial/ventricular electrogram amplitude ratio at successful ablation target of accessory pathways in patients with Ebstein's anomaly.

Knowledge about local electrogram and atrial/ventricular electrogram amplitude ratio (A/V ratio) at the true atrioventricular ring for successful ablation of accessory pathways (APs) in patients with Ebstein's anomaly is limited. Twenty-two adults with Ebstein's anomaly and APs were managed by 24 sessions of radiofrequency catheter ablation (RFCA). A right atrial/ventricular angiogram with or without 3-dimensional electroanatomic mapping was performed to delineate the true atrioventricular ring and atrialized right ventricle (ARV). Electrograms of successful targets were analyzed. For each right-sided AP target, 2 AP targets matched by location and conduction property from normal hearts were selected as controls, and their A/V ratios were compared. In 32 right-sided APs of all 22 patients, local ventricular activation at successful site presented as normal electrogram in 14, fractionated ventricular electrogram (FVE) in 16, and double ventricular potentials in 2. The bipolar voltage of ARV was markedly lower than in normal hearts. The A/V ratio at the successful target was significantly higher in APs with FVE than in control (1.64 ± 1.34 vs. 0.47 ± 0.19, P < 0.01), and was similar in APs with normal ventricular electrogram and in the control (0.38 ± 0.15 vs. 0.46 ± 0.15, P = 0.1726). The A/V ratio at the successful target with double ventricular potentials (after surgical correction) was 0.30 ± 0.20. All APs were successfully ablated without complications. In patients with Ebstein's anomaly, FVE was found in 50% of the successful targets of APs. High A/V ratio at successful sites with FVE and normal A/V ratio at targets with normal ventricular electrogram can facilitate target recognition and ablation.

ASSA14-02-11 Catheter ablation of anteroseptal accessory pathway: Implication for the strategies of mapping and ablation

<h3>Objective</h3> 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. <h3>Methods</h3> 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. <h3>Results</h3> 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. <h3>Conclusions</h3> 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.

Mechanisms and clinical significance of adenosine-induced dormant accessory pathway conduction after catheter ablation.

Adenosine can unmask dormant pulmonary vein conduction after isolation. The role of adenosine in uncovering dormant accessory pathway (AP) conduction after AP ablation is unknown. We evaluated 109 consecutive patients (age, 41 ± 28 years; 62 [57%] men) who were administered adenosine after successful AP ablation. Dormant AP conduction was defined as adenosine-induced recurrent AP conduction, as demonstrated by recurrent preexcitation or change in retrograde ventriculoatrial activation patterns. Dormant AP conduction was identified in 13 (12%) patients. Adenosine led to transient retrograde AP conduction in 6 patients and transient anterograde AP conduction in 8 patients. In all these cases, adenosine-induced AP conduction occurred during the bradycardia phase of adenosine effect and resulted in dormant AP conduction times shorter than atrioventricular nodal conduction times before adenosine administration. On the basis of analysis of timing of occurrence of dormant AP conduction, the mechanism of adenosine-induced AP conduction was determined to be caused by AP excitability recovery in ≥ 12 (92%) cases. The presence of dormant AP conduction was a significant predictor of chronic recurrent AP conduction requiring repeat ablation (odds ratio, 8.54; 95% confidence interval, 1.09-66.9; P=0.041). Adenosine can unmask dormant AP conduction after catheter ablation. Direct effects of adenosine on the AP, possibly via AP membrane potential hyperpolarization, are the dominant mechanism of adenosine-induced AP conduction after ablation. Dormant AP conduction is associated with higher rates of recurrent AP conduction requiring repeat ablation.

Successful catheter ablation of a left anterior accessory pathway from the non-coronary cusp of the aortic valve

Left anterior accessory pathways are considered to be rare findings. Catheter ablation of accessory pathways in this location remains a challenging target, and few reports about successful ablation of these accessory pathways are available. We describe our experience regarding a case of a manifest left anterior accessory pathway ablation using radiofrequency energy at the junction of the left coronary cusp with the non-coronary cusp.

Catheter Ablation of an Unusual Decremental Accessory Pathway in the Left Coronary Cusp of the Aortic Valve Mimicking Outflow Tract Ventricular Tachycardia

The anatomic location of atrioventricular (AV) bypass tracts (or accessory pathways) is variable, but these generally traverse the tricuspid or mitral annulus and insert into the atrium and ventricle near the AV ring. There is only 1 case report of an accessory pathway ablated in the left coronary cusp (LCC),1 and this pathway had bidirectional conduction, was not decremental, and was associated with an orthodromic tachycardia. We report here the first case of an antegrade slowly conducting, decremental, accessory pathway that was also successfully ablated in the aortic LCC. This pathway generated antidromic tachycardia having a QRS morphology mimicking those seen in outflow tract ventricular tachycardia. A 42-year-old woman was evaluated for palpitations and presyncope for 2 years. These were commonly associated with shortness of breath and chest heaviness that would resolve spontaneously. Her baseline ECG was normal without ventricular preexcitation. Echocardiogram, coronary angiogram, and thyroid function were also unremarkable. On her third presentation to a hospital, a broad complex tachycardia was captured (representative 12-lead ECG shown in Figure 1). The cycle length was 480 ms, the QRS duration was 150 ms, and a left bundle branch morphology with a right inferior axis was noted. She was referred for ablation of suspected ventricular outflow tract tachycardia. Consent was obtained for mapping and ablation of this tachycardia. During placement of catheters, a spontaneous initiation of tachycardia occurred, which was noted to have 1:1 AV association. A quadripolar catheter was placed at the right ventricular apex and His bundle, with a decapolar catheter in the coronary sinus. During ventricular pacing, retrograde conduction occurred with a long ventriculoatrial interval. Tachycardia was readily initiated with ventricular premature beats showing retrograde decremental conduction (Figure 2). An antegradely conducting accessory pathway was noted during atrial pacing maneuvers. During delivery of premature atrial stimulations, shortening of …

Vectorcardiography shows cardiac memory and repolarization heterogeneity after ablation of accessory pathways not apparent on ECG

BackgroundPacing induced cardiac memory is an established phenomenon, but following successful WPW ablation, cardiac memory was present on ECG in variable proportions of patients depending on accessory pathway (AP) location. We hypothesized that vectorcardiography (VCG), which is more sensitive than ECG, would show cardiac memory after WPW ablation independent of AP location. MethodsThirty-six patients were followed after successful AP ablation, 11 with overt posteroseptal (PS), 13 with overt left-sided (LS) and 12 with concealed APs (controls). VCGs were recorded the day before and after the procedure, ≥once/week for 6–8weeks and after ≥3months. T vector and T-vector loop parameters were analyzed and compared. ResultsAfter ablation of overt APs, there was a correlation between the directions of the preexcited maximum QRS-vector and the post-ablation maximum T-vector, confirming the presence of cardiac memory. Ablation of overt APs was followed by cardiac memory apparent in different directions. Thus, ablation of PS APs was followed by most pronounced changes in T-vector elevation and LS APs with significant changes only in T-vector azimuth. Cardiac memory disappeared within a month in >80% of cases. Furthermore, T-vector loop morphology changes suggested a period of repolarization heterogeneity immediately after ablation of overt APs. ConclusionsAccording to VCG analysis cardiac memory was present after ablation of overt APs independent of location as consistently as after ventricular pacing, and disappeared within a similar time frame during normal ventricular activation. In addition, signs of transient repolarization heterogeneity were observed after ablation of overt APs.

The left coronary cusp as an unusual location for accessory pathway ablation

The aortic valve borders the anterior part of the mitral annulus, which explains the usual absence of antrioventricular accessory pathway (AP) in this area (Figure 1A). However, few cases of AP ablation in the noncoronary cusp (NCC) have been reported. 1 Suleiman M. Powell B. Munger T. Asirvatham S. Successful cryoablation in the noncoronary aortic cusp for a left anteroseptal accessory pathway. J Interv Card Electrophysiol. 2008; 23: 205-211 Crossref PubMed Scopus (29) Google Scholar , 2 Suleiman M. Brady P. Asirvatham S. Friedman P. Munger T. The noncoronary cusp as a site for successful ablation of accessory pathways: electrogram characteristics in three cases. J Interv Card Electrophysiol. 2011; 22: 203-209 Google Scholar , 3 Tada H. Naito S. Nogami A. Taniguchi K. Successful catheter ablation of an anteroseptal accessory pathway from the noncoronary sinus of Valsalva. J Cardiovasc Electrophysiol. 2003; 14: 544-546 Crossref PubMed Scopus (49) Google Scholar We report here the first case of AP ablation in the left coronary cusp (LCC) and discuss its anatomic substrate.

Early repolarization in Wolff-Parkinson-White syndrome: prevalence and clinical significance

Idiopathic ventricular fibrillation (IVF) with early repolarization (ER) has recently been reported; however, ER is a common finding in healthy subjects and is also found sporadically in patients with Wolff-Parkinson-White (WPW) syndrome. The present study was designed to evaluate the prevalence and clinical significance of ER in patients with WPW syndrome. One hundred and eleven patients with WPW syndrome were studied retrospectively. Early repolarization was defined as QRS slurring or notching with J-point elevation ≥ 1 mm. The prevalence of ER was determined before and after successful catheter ablation. Before ablation, ER was found in 35 of 75 patients with a left free wall, 6 of 23 with a right free wall, and 7 of 13 with a septal accessory pathway (48 of 111, 43% as a whole). Early repolarization was always observed in leads with positive deflection of the initial part of the delta wave. After successful ablation of accessory pathways, ER was preserved in 28 (25%), disappeared in 20 (18%), and newly developed in 8 (7%) patients. In the remaining 55 (50%) patients, ER was not observed either before or after ablation. In patients with persistent ER, the amplitude and width of ER were significantly decreased 3-7 days after the ablation (1.7 ± 0.7 vs. 1.4 ± 0.6 mm, P < 0.005 and 42 ± 11 vs. 34 ± 9 ms, P < 0.001, respectively). In patients with WPW syndrome, ER could be partly related to early depolarization through the accessory pathway. However, persistent ER and new ER appearing after the ablation were frequently found. Therefore, in these patients, mechanisms other than early depolarization may be involved in the genesis of ER.

Cardiac Resynchronization Therapy by Ablation of Right-Anterolateral Accessory Pathway

Ventricular preexcitation caused by right-sided accessory pathways can lead to abnormal septal motion patterns and may be associated with left ventricular (LV) dysfunction and heart failure, despite the lack of a clinical arrhythmia. Hence successful ablation of the accessory pathway abolishes not only preexcitation but also ventricular dyssynchrony in these patients. We describe a case of an asymptomatic 20-year-old male presenting with ventricular Type-B preexcitation combined with LV dysfunction. The individual risk of arrhythmic events was enhanced due to competitive sport activities of the patient and a short antegrade refractory period of the accessory pathway. Hence standard radiofrequency ablation of the right anterolateral accessory pathway was performed, despite no history of tachycardia. After successful accessory pathway ablation, normalization of LV size and function was demonstrated by echocardiography with a long-term follow-up of 4 years.

Symptomatic improvement after catheter ablation of supraventricular tachycardia measured by the arrhythmia-specific questionnaire U22

Introduction. The main indication for ablation of supraventricular tachycardia is symptomatic relief. Generic measures of quality of life are not suitable for direct evaluation of arrhythmia-related symptoms, and a specific tool is needed. The questionnaire U22 quantifies symptoms associated with arrhythmic events. It uses discrete 0–10 scales for quantification of influence of arrhythmia on well-being, intensity of discomfort, type of dominant symptom, and a time aspect that summarizes duration and frequency of spells. We evaluated U22 in a well defined group of patients with paroxysmal supraventricular tachycardia, undergoing an intervention with a distinct end-point and a high success rate.Methods. Symptoms in patients with accessory pathway and atrioventricular nodal re-entrant tachycardia scheduled for ablation were measured with U22 and SF-36 on admission. The evaluation was repeated after 6 months.Results. Altogether 58 patients successfully ablated in 2006–2008 completed the four forms (U22 and SF-36 at base-line and follow-up, 210 ± 35 days after ablation). The score for well-being (0–10; 10 being best) increased from 5.9 ± 2.6 to 7.9 ± 1.9 (P < 0.0005). The score for arrhythmia as cause for impairment in well-being (0–10; 10 being highest) decreased from 7.5 ± 2.8 to 2.0 ± 3.1 (P < 0.0005). The time aspect score (0–10) decreased from 4.7 ± 1.5 to 1.4 ± 1.8 (P < 0.0005). The two SF-36 summary measures PCS and MCS increased from 46.9 ± 9.4 to 48.4 ± 10.7 and from 44.9 ± 12.5 to 49.1 ± 9.9 (P = 0.04 and 0.002).Conclusion. After successful ablation of accessory pathway and atrioventricular nodal re-entrant tachycardia, the U22 protocol detected a relevant increase in arrhythmia-related well-being. Modest improvement in general well-being was detected by the SF-36 protocol.

Incidental Dual Atrioventricular Nodal Physiology in Children and Adolescents: Clinical Follow‐Up and Implications

Dual atrioventricular (AV) nodal physiology is a substrate for the development of AV nodal reentrant tachycardia (AVNRT). However, the risk of developing AVNRT in patients with dual AV nodal physiology is not known. The purpose of this study is to identify the risk of developing AVNRT in children and adolescents with incidental findings of dual AV nodal physiology after accessory pathway ablation. This is a single center retrospective study of patients who underwent intracardiac electrophysiology study at The Children's Hospital, Denver, from March 1993 to August 2008, with findings of dual AV nodal physiology after successful ablation of an accessory pathway. Follow-up was obtained by chart review with the primary outcome of recurrent supraventricular tachycardia. Extended clinical follow-up was also achieved through phone contact with patients or parents of patients. Mean age at initial electrophysiology study was 12.8 years (±3.7 years). Follow-up was obtained on all 66 patients for a mean duration of 3.1 years (±2.8 years). Mean age at follow-up was 15.8 years (±4.6 years). Recurrent supraventricular tachycardia occurred in nine of the 66 patients (13.6%). AVNRT was induced in two of the 66 patients (3.0%). This study supports the hypothesis that incidental dual AV nodal physiology does not predict AVNRT in children and adolescents with after successful accessory pathway ablation.

The Noncoronary Cusp as a Site for Successful Ablation of Accessory Pathways: Electrogram Characteristics in Three Cases

Radiofrequency ablation is the treatment of choice to cure symptomatic patients with atrioventricular accessory pathways (APs). Septal APs are challenging because of the proximity of the normal conduction system. In some patients, despite aggressive lesion creation on the right anteroseptal region pathway, ablation is unsuccessful. We report 3 cases where the successful ablation site was in the noncoronary cusp of the aortic valve and discuss possible defining features of this variant of septal APs and an approach for successful ablation.

The role of the accessory pathway radiofrequency catheter ablation in the secondary prevention of the malignant tachyarrhythmias in patients with Wolff-Parkinson-White syndrome

The occurrence of atrial fibrillation (AF) in the presence of an accessory pathway (AP) that conducts rapidly is potentially lethal because the rapid ventricular response may lead to ventricular fibrillation (VF). The aim of the study was to determine long-term efficacy of AP catheter-ablation using radiofrequency (RF) current in secondary prevention of VF in WPW patients. Study included a total of 192 symptomatic WPW patients who underwent RF catheter-ablation of AP in our institution from 1994 to 2007 and were available for clinical follow-up for more than 3 months after procedure. Before ablation, VF was recorded in total of 27 patients (14.1%). In 14 of patients (51.9%) VF was the first clinical manifestation of WPW syndrome. A total of 35 VF episodes were identified in 27 patients. The occurence ofVF was preceded by physical activity or emotional stress in 17.1% of cases, by alcohol abuse in 2.9% and by inappropriate intravenous drug administration in 28.6%. In addition, no clear precipitating factor was identified in 40% of VF cases, while informations about activities preceding 11.4% of VF episodes were not available. The follow-up of 5.7 +/- 3.3 years was obtained in all of 27 VF patients. Of the 20 patients who underwent successful AP ablation, all were alive, without syncope or ventricular tachyarrhythmias during long-term follow-up. In 4 of 7 unsuccessfully treated patients, recurrence of supraventricular tachycardia and/or preexcited atrial fibrillation were recorded; one of these patients suddenly died of VF, 6 years after procedure. In significant proportion of WPW patients, VF was the first clinical manifestation of WPW syndrome, often precipitated by physical activity, emotional stress or inappropriate drug administration. Successful elimination of AP by percutaneous RF catheter-ablation is highly effective in secondary prevention of life-threatening tachyarrhythmias in patients with ventricular preexcitation.

Remote-controlled catheter ablation of accessory pathways: results from the magnetic laboratory

This study evaluates feasibility, safety, and efficacy of magnetic remote-controlled accessory pathway (AP) ablation. The novel magnetic navigation system (MNS) (Niobe, Stereotaxis) creates a steerable magnetic field (0.08 T) controlling the distal magnetic tip of an ablation catheter. In conjunction with a catheter advancer system (Cardiodrive, Stereotaxis) remote catheter ablation is enabled. Conventional electrophysiology study identified AP conduction in 59 patients (37 males, 36+/-14 years, 60 APs). First generation 1-magnet tip (1-M) (group I, n=18), second generation bipolar 3-magnet tip (3-M) (group II, n=27), and third generation quadripolar 3-magnet tip catheters (3-M quad.) (group III, n=14) were used for magnetic remote-controlled ablation. Successful AP ablation was achieved in 67% (group I), 85% (group II), and 92% (group III). A significant decrease of median [IQR: Q1-Q3] fluoroscopy time and dosage was observed: 21.2 [12.1-33.8] min, 1110 [395-3234] microGym2 (group I); 6.5 [4.4-15.4] min, 290 [129-489] microGym2 (group II), and 4.9 [3.4-8.0] min, 129 [74-270] microGym2 (group III). Mean procedure time (217+/-67 min; 182+/-68 min, and 172+/-90 min) significantly decreased in group III. Median number [Q1-Q3] of radiofrequency current applications in groups I, II, and III was 4 [2-9], 4 [2-6], and 2 [2-4], respectively. No complications occurred. Remote AP ablation is safe and feasible using the novel MNS. Introduction of the 3-magnet quadripolar ablation catheter significantly improved the efficacy of the procedure.