Long-Term Results Of Catheter Ablation Research Articles

Long-term results of catheter ablation for AV nodal reentry tachycardias and accessory pathways

Atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia in patients with accessory pathways (AP) are common supraventricular tachycardias. High long-term efficacy of about 97% (AVNRT) and 92% (AP) has been observed in children and adults. The risk of occurring atrioventricular block is low (0.4-0.8% during AVNRT, 0.1-0.2% for AP). Catheter ablation shows alower efficacy of 87-93% and elevated atrioventricular block risk up to 10% in patient groups with complex congenital heart disease. Nonsynchronized ventricular activation during preexcitation or permanent reentrant tachycardias can induce heart failure, and remission of left ventricular function can be expected in > 90% after successful catheter ablation. Therefore, catheter ablation is the long-term therapy of choice for AVNRT and AP with high efficacy and safety for most patient populations.

Long-term results of catheter ablation of idiopathic and structural ventricular tachycardia

Catheter ablation of ventricular tachycardia (VTs) has emerged as an effective treatment modality. Ablation procedures for idiopathic VTs depends on the anatomical origin of the arrhythmias, is highly effective in certain cases, and has been implemented as afirst-line therapy in recent European guidelines. In contrast, catheter ablation of VTs in patients with structural heart disease has asignificant risk of arrhythmia recurrence. Interventional treatment for patients with ischemic cardiomyopathy was studied in multiple randomized multicenter trials and it was shown that catheter ablation was more effective in arrhythmia suppression compared to conservative treatment modalities. Catheter ablation of nonischemic cardiomyopathy suffers from far higher rates of arrhythmia recurrences as documented in several long-term studies and often needs complex procedures with or without epicardial mapping and ablation. There is still no clear proof of amortality benefit from catheter ablation of VTs in patients with or without structural heart disease. Nevertheless, recent guidelines recommend catheter ablation as an alternative to implantation of cardioverter-defibrillators (ICD) in selected cases.

Comparative analysis of long-term outcomes of thoracoscopic and ablation index-guided catheter ablation in patients with non-paroxysmal atrial fibrillation

Aim. To conduct a comparative assessment of the long-term results of thoracoscopic and catheter ablation using the ablation index in patients with non-paroxysmal atrial fibrillation (AF).Methods. A comparative analysis of the long-term results of catheter ablation using the ablation index - group № 1 (36 patients) and thoracoscopic ablation with the left atrial appendage exclusion - group № 2 (42 patients) was performed.Results. The effectiveness of catheter ablation was 57.14%, thoracoscopic ablation - 67.5% at 12-month followup (р=0,128). There were also no statistically significant differences in safety (p=0.55). Analyzing the structure of postprocedural atrial tachycardias in group №1 was demonstrated that AF recurrence was in 93.3%, in group №2 - in 50%. Atypical atrial flutter was documented in 6.6% of cases in group №1 and in 31.5% - in group №2. Typical atrial flutter was documented only in group №2 (18.75% (3)). However, AF recurrence was more common in the catheter ablation group after 6 months of follow-up (p=0.04).Conclusion. Catheter and thoracoscopic ablation are comparable in terms of overall efficacy and safety, however, thoracoscopic ablation provides greater freedom from AF in a 6 month.

Long term results of catheter ablation in patients presented with ventricular storm

Abstract Funding Acknowledgements Type of funding sources: None. Background and Objective Catheter ablation is a treatment option in patients with ventricular tachycardia (VT storm, especially when refractory to medical treatment. In this trial, we aimed to evaluate the long-term results of catheter ablation in patients with VT storm. Method Between January 2015 and January 2022T, we enrolled a total of 65 VT storm patients who underwent catheter ablation. All patients who have either documented episodes of VT or appropriate ICD shocks more than 3in the last 24 hours. Medical treatment with antiarrhythmic drugs was given to all patients before catheter ablation. After the procedure, all-cause mortality, hospitalization due to stroke/myocardial infarction/heart failure, ICD shocks, and anti-tachycardia pacing therapies were recorded during follow-up. Results Among the whole study population (the median age is 65 years (17-85); 56 (86.2%) males) 37 (56.9%) had ischemic CMP, 24 (36.9%) had non-ischemic CMP whose 8 were ARVD, and 3 (4.6%) HCMP. The median left ventricle ejection fraction was 30% (12 – 65%). Activation mapping was performed in 60 patients, and the critical isthmus was ablated in 60 patients whose 22 had more than one critical ablation site. In 3 patients, only substrate mapping was performed, and substrate homogenization was done. In 2 patients, premature ventricular ectopy, which inducted VT, ablation was performed. Epicardial mapping was performed in 23 patients (35.4%). The median follow-up duration was 23 months (1-94 months). During follow-up, 23 patients died, 43 were hospitalized, and four presented again with VS storm. In 13 patients, appropriate shock/pacing therapy was observed. After the index procedure, re-do catheter ablation of ventricular tachycardia was performed in 8 patients. The mean postprocedural VT-free survival time was estimated at 76.5 months (SE:5.0, 95% CI: 66.6-86.4). Conclusion Catheter ablation therapy is an effective option for both acute and long-term management of patients with VT storms. However, postprocedural mortality and morbidity remain high in long-term follow-up duration. Long-term results may be related to the comorbidities and nature of underlying cardiac disorders.

Abstract 14309: Does Obesity Affect the Long-Term Results of Catheter Ablation of Atrial Fibrillation?

Background: The presence of obesity in patients who underwent catheter ablation (CA) of atrial fibrillation (AF) is thought to be a predictor of poor outcomes. Methods: We studied the long-term success of CA of AF in patients with mild to severe obesity and followed them for recurrence of AF/atrial flutter (FL). Results: Of 185 patients (mean age: 60.3 ± 10.7 years, male: 75%), 24 (13%) patients had a normal body mass index (BMI < 25.0 kg/m 2 ), 53 (28.6%) patients were overweight (BMI 25.0-29.9 kg/m 2 ), 78 (42.2%) patients were obese (BMI 30.0-39.9 kg/m 2 ) and 30 (16.2%) had severe obesity (BMI > 40 kg/m 2 ). There were no significant differences in baseline characteristics including age, gender, race, left ventricular ejection fraction, and presence of hypertension, diabetes, and valvular disease. Number of ablations performed in the normal, overweight, obese, and severe obesity groups were 1.3 ± 0.5, 1.4 ± 0.6, 1.5 ± 0.6, and 1.5 ± 0.7, respectively. During a median (±1SE) follow-up of 5.23 ± 0.17 years, 79% in the normal BMI, 70% in overweight, 41% in obese, and 80% in severe obesity group were in sinus rhythm. There was no significant difference among all four groups regarding recurrence of AF/AFL (p=NS). Kaplan-Meier survival analysis showed no significant difference in time to recurrence of AF/AFL based on BMI. Conclusion: Severity of obesity does not predict recurrence of AF/AFL after CA during long-term follow-up.

Long-term results of catheter ablation of atrial fibrillation in patients with a reduced left ventricular ejection fraction

Abstract Objective This study aims to evaluate long-term results after catheter ablation of atrial fibrillation (AF) in patients with reduced left ventricular ejection fraction (LVEF) and to evaluate sinus rhythm (SR) maintenance, clinical status, and echocardiographic parameters in the long-term follow-up period. Material and methods The study included 112 patients (75.5% men, age 59.5±11.5 years) with LV EF <50% underwent radiofrequency catheter ablation for paroxysmal (24%) or persistent (76%) AF. Patients after ablation were followed up for 38.4 (17.7–54.5) months for AF recurrence, functional class, and echocardiographic parameters. Results All patients underwent complete antral isolation of the pulmonary veins, and 95 (84.8%) underwent additional linear ablations in the left atrium. During the follow-up period, 48 (42.8%) patients experienced arrhythmia recurrence in the form of AF, atrial flutter, or ectopic atrial tachycardia. Repeated ablations were required in 35 (31.2%) patients. After ablation, antiarrhythmic drugs continued to be taken in 75 (66.9%) patients. During follow-up, NYHA class improved at least one class more often among patients in stable sinus rhythm than patients with recurrences (77.5% vs 51.2%, p=0.003). LV EF improved in patients maintaining sinus rhythm (36.6% vs 19.4%; P=0.016), and the degree of mitral regurgitation was significantly reduced (P<0.001) only in these patients. On multivariate analysis, maintenance of sinus rhythm was an independent predictor (odds ratio 4.56, 95% CI 1.69–9.94, P=0.002) of long-term clinical improvement (reduction in NYHA class ≥1 and relative improvement in LVEF ≥10%). Conclusions In patients with reduced LV EF, maintenance of sinus rhythm after ablation is associated with more significant clinical improvement. In the long-term period, the effectiveness of AF ablation in patients with reduced LVEF, as an improvement in the NYHA class and an increase in LVEF, is affected by a high rate of long-term recurrences. Funding Acknowledgement Type of funding sources: None.

Acute and Long-Term Results of Catheter Ablation of Outflow Tract Arrhythmias using Remote Magnetic Navigation with Catheter–Tissue Contact Feedback Technology: Comparison with Manual Ablation

Acute and Long-Term Results of Catheter Ablation of Outflow Tract Arrhythmias using Remote Magnetic Navigation with Catheter–Tissue Contact Feedback Technology: Comparison with Manual Ablation

Treatment strategy and endpoint of catheter ablation for bi-atrial tachycardia after substrate modification ablation in a low voltage zone of the left atrial anterior wall: Long-term results.

BackgroundThe termination of bi‐atrial tachycardia (BiAT) via the ablation of the Bachmann's bundle (BB) and mitral isthmus (MI) has been previously reported; however, the strategy and long‐term results of catheter ablation for BiAT remain unclear.MethodsThe data of nine patients with BiAT who underwent low voltage zone (LVZ) ablation of the left atrial anterior wall (LAAW) after pulmonary vein isolation were reviewed. Patients with a P wave duration <100 ms during sinus rhythm underwent MI ablation and those with a P wave duration >100 ms underwent BB ablation.ResultsMI ablation was performed in three patients and six patients underwent BB ablation. The difference in the P wave duration before and after ablation was significantly different between the ablation sites (MI group: 5.0 ms difference; BB group; 38.5 ms difference; P = .024). The P wave duration was prolonged by >20 ms and was 120 ms or more after ablation in 5/6 patients who underwent BB ablation. The total recurrence rate was 11.0% (mean: 26.9 months).ConclusionThe recurrence of BiAT after MI or BB ablation is low. When BB ablation was performed, the P wave duration was prolonged by >20 ms and was at least 120 ms after the ablation, which may be an endpoint that can be used to measure the success of the ablation.

Outcomes after catheter ablation for treatment of electrical storm in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia

Catheter ablation is an effective treatment for ARVC/D-associated ventricular tachycardia (VT), however its benefit as an urgent treatment for electrical storm (ES) remains to be assessed. Report the acute and long-term results of catheter ablation in patients with ARVC/D presenting with ES. Consecutive patients with a diagnosis of ARVC/D who underwent urgent catheter ablation for ES from five different French centers were retrospectively included. Between 2003 and 2015, 23 patients with ARVC/D (mean age 43.6 ± 16.7 years) underwent 24 VT catheter ablation procedures for ES. Median time from ARVC diagnosis to ES was 3.4 years [−4.4–39.2]. A total of 53% of patients had previous VT ablation and 78% had an implantable cardioverter-defibrillator. All but 2 patients were on beta-blockers and/or antiarrhythmic therapy. Four patients presented with cardiogenic shock. Diffuse RV structural abnormalities was present in 70% of patients, 61% had RV systolic dysfunction and 35% of patients had left ventricular ejection fraction < 50%. Only 8% of patients had more than 1 documented VT whereas 63% had multiple induced sustained VT. The clinical VT was inducible in 79% of the procedures. The median number of targeted VTs and sites were 1 [1–6] and 1 [1–5], respectively. Acute success defined as inability to induce any sustained VT was obtained in 53% but the clinical VT remained non-inducible in 100% of procedures. At 1 follow-up year, cumulative probability of freedom from VT recurrence was 75%. During a median follow-up time of 3.9 years (1 month–10 years), only one ES reoccurred when 17% patients developed end-stage heart failure with one death and three hearts transplantation unrelated to arrhythmia. Catheter ablation is efficient in reducing the arrhythmic burden in patients with advanced ARVC/D presenting with ES. However, ES could be associated with poor homodynamic long-term outcome.

56-06: Long-Term Results of Catheter Ablation for Paroxysmal Atrial Fibrillation in Very Young Adults – A 5-Year Follow-Up Study

Introduction: Catheter ablation is an established therapy for the treatment of symptomatic atrial fibrillation (AF). Current guidelines recommend catheter ablation for drug-refractory paroxysmal AF (PAF) in adults, and as first-line therapy in selected patients. However, long-term data on the efficacy and safety of catheter ablation for PAF in young adults is very limited. Methods: From 2005 to 2014, 52 consecutive young adults (32 men, 20 women) with symptomatic PAF underwent pulmonary vein isolation (PVI). The procedure end point was complete PVI (entrance block) verified by circular catheters placed within the PVs. Follow-up was based on regular outpatient clinic visits including 24h Holter-ECGs and telephone interviews at last follow-up. Recurrence was defined as any symptomatic and/or documented atrial tachyarrhythmia episode [30 s following a 3-month blanking period]. Results: Mean patient age at the time of the index procedure was 30 ± 4 years (range 19-35). Complete PVI by either radiofrequency current guided by 3-dimensional mapping (n = 50) or cryoballoon (n = 2) was achieved in 51/52 patients (98%). Six patients were lost to follow-up. During a mean follow-up period of 4.9 years (range 1.0-9.7 years) stable sinus rhythm was achieved in 65% after a single procedure, and in 83% after multiple procedures (mean 1.5; range 1-3). Success rate at last follow-up off anti-arrhythmic drugs was 74%. Eight patients (17%; 3 with stable sinus rhythm) were taking antiarrhythmic drugs (AAD; only class I) at last follow-up compared to 26 patients (57%, p < 0.01) before the index procedure. A second procedure was performed in 19, and a third procedure in 2 patients. PV reconduction was observed in 16 patients (84%) during the second, and in 1 patient (50%) during the third procedure. EHRA score significantly improved at last follow-up (mean 3.2 to 1.2, p < 0.001). Major periprocedural complications occurred in 3 patients (tamponade in 1, PV stenosis in 2). No patient progressed towards persistent AF. Conclusions: In the majority of very young adults ≤35 years of age, catheter ablation for PAF is effective during long-term follow-up and associated with a low complication rate. These findings support the concept of PVI in very young adults with symptomatic PAF.

16-07: Long-Term Results of Catheter Ablation for Persistent Atrial Fibrillation in Very Young Adults – Lessons from a 4-year follow up

16-07: Long-Term Results of Catheter Ablation for Persistent Atrial Fibrillation in Very Young Adults – Lessons from a 4-year follow up

Long-term results of catheter ablation of atrial fibrillation: cure or just palliation?

Knowing the pitfalls when evaluating the long-term results after catheter ablation of atrial fibrillation enables a critical analysis of the outcome presented in numerous studies on this topic. Nevertheless, catheter ablation is a long-term successful and safe therapeutic procedure for symptomatic atrial fibrillation, especially for patients with paroxysmal atrial fibrillation. In patients with persistent symptomatic atrial fibrillation, the decision for ablation has to be made with caution due to a higher recurrence rate and higher likelihood for multiple procedures.

Long-term results of catheter ablation of focally-triggered electrical storm in patients with coronary artery disease

Long-term results of catheter ablation of focally-triggered electrical storm in patients with coronary artery disease

Long-term results of catheter ablation for atrial fibrillation in 866 patients

PurposeThis study presents eight-year experience with ablation techniques, recurrent arrhythmias, and long-term outcomes in patients undergoing catheter ablation for atrial fibrillation (AF). MethodsCatheter ablation of AF was performed in 866 consecutive patients in a total of 1272 ablation procedures. Ablation strategy and procedure endpoints were left at the operator's discretion. Total study population and groups of paroxysmal (n=508/59%), persistent (n=102/12%), and long-standing persistent AF (n=256/29%) were evaluated. ResultsPulmonary vein isolation alone or with cavo-tricuspid isthmus ablation was accomplished in 36% of the patients. It was significantly more often used in paroxysmal AF than in persistent or long-standing persistent AF (both p<0.001). More extensive ablation prevailed in persistent AF types. Ablation was repeated in 307 (35%) patients. Patients with long-standing persistent AF underwent significantly more repeat procedures than patients with paroxysmal AF (p<0.001) or persistent AF (p=0.001). Recurrent AF dominated before the first repeat ablation in 68% cases, while recurrent atrial tachycardia (AT) prevailed before the second (73%), and third (93%) repeat ablation. Patients with long-standing persistent AF presented with recurrent AT in 50% of the cases already before the first repeat ablation. At the end of 49±26 month follow-up, 83% of the patients remained in stable sinus rhythm (SR); 70% of the patients without antiarrhythmic drugs. SR maintenance was insignificantly superior in long-standing persistent AF group (91%) compared to paroxysmal AF (82%) and persistent AF patients (68%). ConclusionPatients with persistent AF types underwent more extensive initial ablation. Patients with long-standing persistent AF experienced best long-term outcome likely as a consequence of higher number of repeat ablation procedures.

A Novel Finding: Atrial Substrate Properties and Long-Term Results of Catheter Ablation in Chronic Atrial Fibrillation Patients with Left Atrial Spontaneous Echo Contrast

Background: The atrial substrate in chronic atrial fibrillation (AF) patients with left atrial spontaneous echo contrast (LASEC) has not been previously reported. Methods: Of 36 consecutive patients with chronic AF who received stepwise ablation approach, 18 patients with an LASEC (group I) were compared with 18 age-gender-left atrial volume matched patients without an LASEC (group II). The atrial substrate properties including atrial voltage, dominant frequency (DF), and complex fractionated electrograms (CFEs) in the bi-atrial were evaluated. Result: The left atrial voltage (1.0±0.6 vs. 1.6±0.7 mV, p=0.04), total activation time (119±20 vs. 103±13 msec, p<0.001) and DF (7.3±1.3 vs. 6.6±0.7 Hz, p<0.001) differed between group I and group II, respectively. The bi-atrial CFEs did not differs between group. After a mean follow-up of 30±13 month, there were significant differences in the anti-arrhythmic drugs (1.1±0.3 vs. 0.7±0.5, p=0.02) needed after ablation, and recurrence as persistent AF (92% vs. 50%, p=0.03) between group I and group II, respectively. After multiple procedures, there were more group II patients that remained in SR, when compared with group I (78% vs. 44%, p=0.04). Conclusion: There was a poorer atrial substrate, lesser SR maintenance after catheter ablation and need for more anti-arrhythmic drugs in the chronic AF patients with LASEC when compared with those without LASEC.

Long-Term Results of Catheter Ablation in Paroxysmal Atrial Fibrillation

Background— Paroxysmal atrial fibrillation (AF) naturally progresses toward chronic AF at an estimated rate of 15% to 30% over a 1- to 3-year period. Pulmonary vein (PV) isolation is increasingly performed for the treatment of drug-refractory paroxysmal AF. The long-term data on clinical outcome after circumferential PV isolation are limited. Methods and Results— From 2003 to late 2004, 161 patients (121 men; age, 59.8±9.7 years) with symptomatic paroxysmal AF and normal left ventricular function underwent circumferential PV isolation guided by 3-dimensional mapping and double Lasso technique. Right-sided and left-sided continuous circular lesions encircling the ipsilateral PVs were placed with irrigated radiofrequency energy. The procedure end point was the absence of all PV spikes for at least 30 minutes after PV isolation verified by 2 Lasso catheters placed within the ipsilateral PVs. Sinus rhythm was present in 75 patients (46.6%) after the initial procedure during a median follow-up period of 4.8 years (0.33 to 5.5 years). A second procedure was performed in 66 and a third procedure in 12 patients. Recovered PV isolation conduction was observed in 62 of 66 patients (94.0%) during the second and in 8 of 12 patients (66.7%) during the third procedure. After a median of 1 (1 to 3) procedure, stable sinus rhythm was achieved in 128 of 161 patients (79.5%), whereas clinical improvement occurred in an additional 21 of 161 patients (13.0%) during a median follow-up of 4.6 years (0.33 to 5.5 years). Four patients in stable sinus rhythm died during follow-up. Progression toward chronic AF was observed in 4 patients (2.4%); however, only 2 patients reported symptoms. Conclusion— In patients with paroxysmal AF and normal left ventricular function, circumferential PV isolation results in stable sinus rhythm in the majority of patients, and low incidence of chronic AF was observed after ablation during up to 5 years of follow-up.

CATHETER ABLATION OF VENTRICULAR TACHYCARDIA - LONG-TERM RESULTS

Ventricular tachycardia represents life-threatening cardiac rhythm disturbance and catheter ablation using radiofrequency current provides powerful means for definitive cure of almost all monomorphic tachyarrhythmias. Presence and extent of underlying structural heart disease is important for further prognosis of the patients, who undergo catheter ablation of ventricular tachycardia. Long-term results of catheter ablation for ventricular tachycarida in patients with and without structural heart disease are presented. Patients and results: Twenty three patients (9 females) aged 49.1 ± 15.6 (18–72) years underwent catheter ablation for monomorphic (resp. polymorphic in one patient) ventricular tqachycardia in 30 ablation procedures. Patients with structural heart disease: Seven patients (2 females) aged 54.2 ± 19.8 (21–72) years had structural heart disease (5 patients – post myocardial infarction, 1 patient – arrhythmogenic right ventricular dysplasia, 1 patient – surgically corrected transposition of great arteries). All sustained monomorphic ventricular tachycardias were eliminated during the catheter ablation and no ventricular tachycardia recurred during the follow-up period in 4 patients. In two patients sustained monomorphic ventricular tachycardia was not eliminated with radiofrequency current. One of the patients remains free of ventricular tachycardia and one patient experienced one recurrence of slowed ventricular tachycardia. Thus long-term clinical success was achieved in 4 patients and some clinical benefit probably also in the latter two patients. A different ablation strategy targeting large arrhythmogenic area at the border of postmyocardial infarction scar was employed in the last patient with frequent ICD discharges for polymorphic ventricular tachycardia associated with hemodynamic deterioration. This procedure brought immediate and long-term significant reduction of ICD shocks and rehospitalizations and probably was life-saving. Patients without structural heart disease: In sixteen patients (7 females) aged 44.2 ± 12.8 (18–66) years no structural heart disease was found. These patients presented with documented ventricular ectopy in different forms from incessant ventricular premature beats through repetitive nonsustained ventricular tachycardia to paroxysmal sustained ventricular tachycardia. The arrhythmia originated in the right ventricle in 11 patients (right ventricular outflow tract in 10 patients and basolateral wall in 1 patient) and in the left ventricle in 5 patients (inferoapicoseptal region in 4 patients and basoinferoseptal region in 1 patient). Eleven patients (68.7 %) had the arrhythmia eliminated or markedly suppressed during the ablation procedure and remain free of palpitations and antiarrhythmic drugs. Two patients with partial suppression of the ectopic rhythm are less symptomatic and the antiarrhythmic drugs could be reduced. In one patient one ventricular tachycardia morphology from the right ventricular outflow tract was eliminated while the second ventricular tachycardia morphology was not targeted (and was suppressed by antiarrhythmic drug) for close vicinity of the arrhythmogenic focus to the left anterior descending artery. Thus the clinical benefit of the ablation procedure is enhanced to 14 (87.5 %) patients. Ablation completely failed in two patients. Conclusion: Radiofrequency catheter ablation of ventricular tachycardia is highly effective and safe and results in long-term arrhythmia elimination. In patients with underlying structural heart disease it should be currently viewed as a adjunctive therapy to a complex management of the patient, while in otherwise healthy patients it can be considered a method for permanent cure.

Idiopathic monomorphic ventricular tachycardia: clinical outcome, electrophysiologic characteristics and long-term results of catheter ablation

Ventricular tachycardia (VT) without structural heart disease or any identifiable predisposing causes for arrhythmia is an uncommon but well-recognized clinical entity. The purpose of this study is to assess the results of catheter ablation therapy and the long-term outcome of patients with idiopathic monomorphic VT in a large patient group. Sixty-one consecutive patients (male/female=40/21; mean age 38±16 years) with idiopathic VT underwent electrophysiologic study and an attempt of catheter ablation therapy. The `left VT' group included 31 patients with QRS morphology of right bundle branch block during VT suggestive of the VT originating from the left ventricle (LV), and the `right VT' group consisted of 30 patients with QRS morphology of left bundle branch block with normal or right frontal axis deviation suggestive of VT arising from right ventricular outflow tract (RVOT). Idiopathic left VT has sustained VT during the clinical attacks, baseline electrophysiologic study or after isoproterenol infusion; it can be entrained by overdrive ventricular pacing, terminated by verapamil, but not by adenosine (except one case with VT focus at left ventricular free wall). Catheter ablation was successful in 22 (84%) of 26 patients, with recurrence rate of 9%. The successful ablation sites were located at LV inferior-apical septum (16 patients), mid-septum (three patients), high septum (two patients) and high anterior wall (one patient). In the right VT group, 20 (67%) of 30 patients presented clinically repetitive monomorphic VT. Most of the idiopathic right VT (22/30) required isoproterenol to facilitate induction of VT, and were sensitive to both verapamil and adenosine. Successful catheter ablation was achieved in 21 (84%) of 25 patients, with recurrence rate 19%. The successful ablation sites were located at RVOT-septum in 18 patients, and RVOT-free wall in three patients. During a mean follow-up period of 29.2±21.7 months (range 1–76 months) after hospital discharge, all patients were alive but one left VT case died of non-cardiovascular cause. We concluded that idiopathic left side and right side VTs have their distinct clinical, electrophysiologic and electropharmacological characteristics suggestive of different underlying mechanisms, and both have a benign prognosis. Furthermore, catheter ablation can be effective in eliminating idiopathic VT originating from the right ventricular outflow tract and left ventricle.

Long-term results of catheter ablation for idiopathic ventricular tachycardia originated from the right ventricular outflow.

We performed catheter ablation in 10 consecutive patients with idiopathic monomorphic right ventricular tachycardia and studied the long-term outcome. All ventricular tachycardias had a left bundle branch block configuration with an inferior axis, and originated from right ventricular outflow. Antiarrhythmic drugs (3-6 drugs) had been ineffective in controlling ventricular tachycardia. The 2 patients who underwent direct-current ablation (2 shocks of 150 J) had no recurrence of ventricular tachycardia and did not require antiarrhythmic drugs during a follow-up of 56 and 51 months, respectively. Of the 8 patients who underwent radiofrequency ablation (30-40 watt, 20-40 sec, 2-15 application, using Inter Nova RA 50, 13.56 MHz), 1 patient had no recurrence of ventricular tachycardias and did not require antiarrhythmic drugs, 4 patients had no recurrence of ventricular tachycardias but did require anti-arrhythmic drugs, and 3 patients experienced recurrence of non-sustained ventricular tachycardia despite the use of antiarrhythmic drugs during a follow-up of 15-40 months. There were no complications except for cardiac perforation which occurred immediately after direct-current ablation in 1 patient. In conclusion, long-term success in preventing ventricular tachycardia was achievable with direct-current ablation, but this success was associated with serious risks, such as cardiac perforation. Radiofrequency ablation was safer than direct-current ablation, but had a lower long-term success rate.

Early and long-term results of catheter ablation in patients with incessant ventricular tachycardia.

Catheter ablation of sustained monomorphic ventricular tachycardia (VT) with high energy DC shock (360-400 J) was performed in 11 patients with incessant VT (duration greater than 24 hours), refractory to antiarrhythmic drugs, and DC cardioversion. There were ten patients with coronary disease and one patient had dilated cardiomyopathy. Direct current energy was delivered at the earliest endocardial activation in six patients (group I) or at the area of slow conduction in five patients (group II). Incessant VT was terminated by DC ablation in nine patients (82%). After the ablation procedure VT remained inducible in four patients in group I (67%) and in one patient (20%) in group II. Two patients in group II had to go to emergent surgery. During the mean follow-up of 31 +/- 26 (1-66) months nonfatal VT recurrences occurred in five patients in group I and in one patient in group II.