Validation of the national Danish ablation database: a retrospective, registry-based validation study.

Aim.To validate the National Danish Ablation Database (NDAD) by investigating to what extent data in NDAD correspond to medical records.Type of study. Non-blinded, registry-based, retrospective, validation study. Material and methods. A sample of patients who underwent ablation for atrial fibrillation in Denmark between 1 January 2016 and 31 December 2016 were included. By utilizing medical records as gold standard, positive predictive (PPV) and negative predictive values (NPV) for NDAD were assessed and presented as five main categories: arrhythmia characteristics, demographics, cardiac history, complications, and medication. PPV's and NPV's exceeding 90% were considered as high agreement. Results. 597 patients (71.0% males) were included in the study. Median age was 63.1 (IQR: 54.9-68.4) years. The median PPV and NPV estimates across all variables were respectively 90.4% (95% CI: 68%-95.2%) (PPV) and 99.4% (95% CI: 98.4%-99.8%) (NPV) at baseline, and 91.7% (95% CI: 67.4%-95.4%) (PPV) and 99.3% (98.2%-99.3%) (NPV) at follow-up. Conclusion. The data registered in NDAD agrees to a great extent with the patients' medical records, suggesting NDAD is a database with high validity. As a result of low complication rate, the PPV- and NPV-estimates among complication variables were prone to somewhat greater uncertainty compared to the rest.

Periprocedural complications and one-year outcomes after catheter ablation for treatment of atrial fibrillation in elderly patients: a nationwide Danish cohort study.

OBJECTIVES: To investigate complications within 30-days following first-time ablation for atrial fibrillation (AF), including a composite of cardiac tamponade, hematoma requiring intervention, stroke or death, in patients ≥ 75 years of age, compared to patients aged 65-74 years. In addition, one-year all-cause mortality and AF relapse were compared. METHODS & RESULTS: All patients receiving their first catheter ablation for AF between 2012 and 2016 were identified using Danish nationwide registries. Patients aged 65-74 years served as the reference group for patients ≥ 75 years. Relapse of AF within one year was defined as cardioversion following a three-month blanking period, re-ablation or confirmed relapse within follow-up. The composite complication outcome did not differ between the two age groups, with 39/1554 (2.8%) in patients 65-74 years of age, versus 5/199 (2.5%) in older patients (adjusted HR = 0.94), 95% CI: 0.37-2.39, P = 0.896). Patients ≥ 75 years or older had no increased hazard of death within 30 days after the procedure, with an incidence of 3/1554 (0.2%) in younger patients and 2/199 (1.0%) in patients ≥ 75 years of age (adjusted HR = 4.71, 95% CI: 0.78-28.40, P = 0.091). There was no difference in relapse of AF after one year between age groups (≥ 75 years adjusted HR = 1.00, 95% CI: 0.78-1.26, P = 0.969). CONCLUSION: In patients ≥ 75 years of age selected for catheter ablation for AF, the incidence of periprocedural complications, as well as one-year freedom from AF showed no statistical difference, when compared to patients 65-74 years of age.

Discontinuation of oral anticoagulation and risk of stroke and death after ablation for typical atrial flutter: A nation-wide Danish cohort study.

INTRODUCTION: Oral anticoagulation (OAC) is indicated for patients with atrial fibrillation (AF) and atrial flutter (AFL) with a CHA2DS2-VASc score ≥ 2 for men and ≥3 for women. This is regardless of successful catheter ablation for their arrhythmia. Studies have mainly focused on AF, and little is known regarding use of OAC in AFL patients following catheter ablation. PURPOSE: To describe discontinuation of OAC in a national cohort of patients who have undergone first-time cavo-tricuspid isthmus ablation (CTIA) for AFL. METHODS: We identified patients undergoing first-time CTIA during the period 2010-2016 using the Danish National Ablation Registry. Information on comorbidities and OAC use were gathered using the Danish National Patient Registry and the Danish National Prescription Registry. Patients were followed until March 1st, 2018. RESULTS: We identified 2409 consecutive patients. Median age was 66 (IQR 58-72) years, and 1952 (81%) were men. During mean follow-up of 4 ± 1.7 years, 723 (30%) patients discontinued OAC. Patients discontinuing OAC were younger, had less comorbidity, and a lower CHA2DS2-VASc score. During follow-up, 252 (10%) patients died, and 112 (5%) patients had a stroke. Incidence of both these events increased with increasing age and CHA2DS2-VASc score. In adjusted analysis, we observed higher mortality (p < 0.0001) in patients discontinuing OAC, while stroke rate was not significantly higher (p = 0.21). CONCLUSION: In this national cohort of patients who have undergone first-time CTIA, patients discontinuing OAC treatment were younger and had less comorbidities. Patients remain at elevated risk of death and stroke/TIA, increasing with their age and CHA2DS2-VASc score.

Recurrent atrial flutter ablation and incidence of atrial fibrillation ablation after first-time ablation for typical atrial flutter: A nation-wide Danish cohort study.

BACKGROUND: Cavo tricuspid isthmus ablation (CTIA) is considered an effective first-line treatment for typical atrial flutter (AFL). However, many patients develop atrial fibrillation (AF) after successful CTIA. Knowledge about recurrent arrhythmia after CTIA mainly comes from small cohort studies with limited follow-up. OBJECTIVE: To describe incidences of re-ablation for AFL and ablation for AF after first-time CTIA in a nation-wide cohort. METHODS: In the Danish National Ablation Registry we identified patients undergoing first-time CTIA during 2010-2016. Subsequent CTIA and AF-ablation procedures were identified until March 1st, 2018. We collected information on patient comorbidities in the Danish National Patient Registry. RESULTS: We identified 2409 patients undergoing first-time CTIA. Median age was 66 (IQR 58-72) years, 1952 (81%) were men, and 78 (3%) patients had a history of previous ablation for AF. Acute procedural success was achieved in 2288 (95%) patients. During mean follow-up of 4.0 ±â€¯1.7 years, 242 (10%) patients underwent CTI re-ablation and 326 (13.5%) underwent ablation for AF. Baseline characteristics associated with CTI re-ablation included prolonged procedural time, unsuccessful index CTIA, age <75 years and CHA2DS2-VASc score <2. Hypertension, history of AF-ablation, age <65 years use of a contact force sensing catheter and CHA2DS2-VASc score <2 were associated with later ablation for AF. CONCLUSION: In a nation-wide cohort undergoing first-time CTIA for AFL, 10% of patients underwent CTI re-ablation and 13.5% ablation for AF during mean follow-up of 4.0 ±â€¯1.7 years. Probability of a second procedure was higher in younger patients with less comorbidities.

Impact of Substrate Modification by Catheter Ablation on Implantable Cardioverter-Defibrillator Interventions in Patients With Unstable Ventricular Arrhythmias and Coronary Artery Disease: Results From the Multicenter Randomized Controlled SMS (Substrate Modification Study).

BACKGROUND: The implantable cardioverter-defibrillator (ICD) is the standard therapy to prevent sudden cardiac death in patients with coronary artery disease and unstable ventricular tachyarrhythmias. The prospective multinational SMS (Substrate Modification Study) was designed to assess whether prophylactic ablation of the arrhythmogenic substrate reduces or prevents the recurrence of ventricular tachycardia/ventricular fibrillation in such patients. METHODS AND RESULTS: Of 111 patients included in an intention-to-treat analysis, 54 were randomly assigned catheter ablation plus ICD implantation (ablation group: 68±8 years; 47 men), whereas 57 were assigned ICD implantation without catheter ablation (ICD-only group: 66±8 years; 46 men). Primary study end point was the time to first recurrence of ventricular tachycardia/ventricular fibrillation. ICD episodes were assessed and verified by an independent board. Patients were followed up for 2.3±1.1 years. The primary end point was reached by 25 ablation patients and 26 ICD-only patients. Two-year event-free survival was estimated at 49.0% (95% confidence interval, 33.3%-62.9%) in the former and 52.4% (36.7%-65.9%) in the latter groups. Comparison of episode incidence revealed no significant difference in the primary end point (P=0.84). In an Andersen-Gill regression model with multiple end point recurrences, the difference between the study arms significantly favored catheter ablation for both the primary end point and all but one of the predefined subgroups of detected arrhythmia events. CONCLUSIONS: SMS failed to meet the primary end point of time to first ventricular tachycardia/ventricular fibrillation recurrence. However, catheter ablation did reduce the total number of ICD interventions during the duration of follow-up. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov. Unique identifier: NCT00170287.

Long-term efficacy of catheter ablation as first-line therapy for paroxysmal atrial fibrillation: 5-year outcome in a randomised clinical trial.

OBJECTIVE: The Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) trial compared radiofrequency catheter ablation (RFA) with antiarrhythmic drug therapy (AAD) as first-line treatment for paroxysmal atrial fibrillation (AF). Endpoint of ablation was elimination of electrical activity inside pulmonary veins. We present the results of the 5-year follow-up. METHODS: This pre-specified 5-year follow-up included assessment of any AF and symptomatic AF burden by one 7-day Holter recording and quality of life (QoL) assessment, using SF-36 questionnaire physical and mental component scores. Analysis was intention-to-treat. Imputation was used to compensate for missing Holter data. RESULTS: 245 of 294 patients (83%) randomised to RFA (n=125) or AAD (n=120) attended the 5-year follow-up, 227 with Holter recording. Use of class I or III AAD was more frequent in AAD group (N=61 vs 13, p<0.001). More patients in the RFA group were free from AF (126/146 (86%) vs 105/148 (71%), p=0.001, relative risk (RR) 0.82; 95% CI 0.73 to 0.93) and symptomatic AF (137/146 (94%) vs 126/148 (85%), p=0.015, χ2 test, RR 0.91; 95% CI 0.84 to 0.98) in 7-day Holter recording. AF burden was significantly lower in the RFA group (any AF: p=0.003; symptomatic AF: p=0.02). QoL scores did not differ between randomisation groups. QoL scores remained improved from baseline (both components p<0.001), and did not differ from 2-year scores. CONCLUSIONS: At 5 years, the occurrence and burden of any AF and symptomatic AF were significantly lower in the RFA group than in the AAD group. Improved QoL scores observed after 2 years persisted after 5 years without between-group differences. TRIAL REGISTRATION NUMBER: NCT00133211; Results.

Safety of novel oral anticoagulants in catheter ablation of atrial fibrillation.

INTRODUCTION: Limited data are available regarding safety of catheter ablation of atrial fibrillation (AF) in patients using novel oral anticoagulants (NOAC) before and after pulmonary vein isolation. We aimed to assess the safety of a simple anticoagulation protocol in consecutive patients presenting for catheter ablation of AF. METHODS: From November 2011 to December 2014, we prospectively included 234 patients referred for catheter ablation of AF who had already received NOAC treatment. NOAC was continued for a minimum of three months after ablation. We assessed procedure-related bleeding or thromboembolic complications, bleeding or thromboembolic complications during a three-month follow-up period and patient-reported adherence to NOAC therapy. The study has not received financial support from external resources. The study was registered with ClinTrials.gov as NCT02569255. RESULTS: A total of 171 patients were treated with dabigatran (94% 150 mg twice daily), 38 with rivaroxaban (100% 20 mg daily) and 25 with apixaban (100% 5 mg twice daily). NOACs were interrupted for 24 hours before and re-administered two hours after the ablation procedure, without bridging with low molecular weight heparin (LMWH). No periprocedural thromboembolic complications and no bleeding complications were registered except for one pericardial effusion which was percutaneously drained without further complications. No thromboembolic or bleeding complications during follow-up were registered. All patients continued the same NOAC during follow-up as before ablation. CONCLUSIONS: Anticoagulation with NOAC with a short period of periprocedural interruption without bridging with LMWH seems safe and well-tolerated. FUNDING: none. TRIAL REGISTRATION: The trial is registered as ClinTrials.gov no. NCT01569255.

Radiofrequency catheter ablation maintains its efficacy better than antiarrhythmic medication in patients with paroxysmal atrial fibrillation: On-treatment analysis of the randomized controlled MANTRA-PAF trial.

BACKGROUND: The Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) is a randomized trial comparing radiofrequency catheter ablation (RFA) to antiarrhythmic drugs (AADs) as first-line treatment of paroxysmal atrial fibrillation (PAF). In order to eliminate the clouding effect of crossover we performed an on-treatment analysis of the data. METHODS AND RESULTS: Patients (n=294) were divided into three groups: those receiving only the assigned therapy (RFA and AAD groups) and those receiving both therapies (crossover group). The primary end points were AF burden in 7-day Holter recordings at 3, 6, 12, 18, and 24 months and cumulative AF burden in all recordings. At 24 months, AF burden was significantly lower in the RFA (n=110) than in the AAD (n=92) and the crossover (n=84) groups (90th percentile 1% vs. 10% vs. 16%, P=0.007), and more patients were free from any AF (89% vs. 73% vs. 74%, P=0.006). In the RFA, AAD and the crossover groups 63%, 59% and 21% (P<0.001) of the patients had no AF episodes in any Holter recording, respectively. Quality of life improved significantly in all groups. There were no differences in serious adverse events between the RFA, AAD and crossover groups (19% vs. 8% vs. 23%) (P=0.10). CONCLUSIONS: In the treatment of antiarrhythmic therapy naïve patients with PAF long-term efficacy of RFA was superior to AAD therapy. Thus, it is reasonable to offer RFA as first-line treatment for highly symptomatic patients who accept the risks of the procedure and are aware of frequent need for reablation(s).

Attitudes toward Catheter Ablation for Atrial Fibrillation: A Nationwide Survey among Danish Cardiologists.

BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an important but expensive procedure that is the subject of some debate. Physicians' attitudes toward catheter ablation may influence promotion and patient acceptance. This is the first study to examine the attitudes of Danish cardiologists toward catheter ablation for AF, using a nationwide survey. METHODS AND RESULTS: We developed a purpose-designed questionnaire to evaluate attitudes toward catheter ablation for AF that was sent to all Danish cardiologists (n = 401; response n = 272 (67.8%)). There was no association between attitudes toward ablation and the experience or age of the cardiologist with respect to patients with recurrent AF episodes with a duration of <48 hours or >7 days and/or need for cardioversion. The majority (69%) expected a recurrence of AF after catheter ablation in more than 30% of the cases. For patients with persistent longstanding AF with a duration of >1 year, the attitude toward ablation for longstanding AF was more likely to be positive with increasing age (P < 0.01) and years of experience of the cardiologist (P = 0.002). CONCLUSIONS: Danish cardiologists generally have a positive attitude toward catheter ablation for AF, maintain up-to-date knowledge of the procedure, and are aware what information on ablation treatment should be given to patients with AF. The cardiologists had a positive attitude toward ablation for AF in patients with AF episodes <48 hours and patients with episodes >7 days, or those who needed medical/electrical conversion, but a more negative attitude toward treating longstanding AF patients.

The cost-effectiveness of radiofrequency catheter ablation as first-line treatment for paroxysmal atrial fibrillation: results from a MANTRA-PAF substudy.

AIM: The aim of this prospective substudy was to estimate the cost-effectiveness of treating paroxysmal atrial fibrillation (AF) with radiofrequency catheter ablation (RFA) compared with antiarrhythmic drugs (AADs) as first-line treatment. METHODS AND RESULTS: A decision-analytic Markov model, based on MANTRA-PAF (Medical Antiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation) study data, was developed to study long-term effects and costs of RFA compared with AADs as first-line treatment. Positive clinical effects were found in the overall population, a gain of an average 0.06 quality-adjusted life years (QALYs) to an incremental cost of €3033, resulting in an incremental cost-effectiveness ratio of €50 570/QALY. However, the result of the subgroup analyses showed that RFA was less costly and more effective in younger patients. This implied an incremental cost-effectiveness ratio of €3434/QALY in ≤50-year-old patients respectively €108 937/QALY in >50-year-old patients. CONCLUSION: Radiofrequency catheter ablation as first-line treatment is a cost-effective strategy for younger patients with paroxysmal AF. However, the cost-effectiveness of using RFA as first-line therapy in older patients is uncertain, and in most of these AADs should be attempted before RFA (MANTRA-PAF ClinicalTrials.gov number; NCT00133211).

[Radiofrequency ablation of atrial fibrillation]. / Radiofrekvensablation af atrieflimren.

New non-pharmacological interventions have evolved over the latest decades in order to prevent atrial fibrillation and/or reduce symptoms. Radiofrequency ablation (RFA) has been performed in Denmark since 2001. In 2011, 2,529 catheter-based RFAs for atrial fibrillation were performed. RFA is now considered a treatment option in patients with drug-refractory atrial fibrillation or young patients who prefer RFA rather than anti-arrhythmic drugs. RFA aims at minimising the impact of "trigger foci" from the pulmonary veins or inhibiting the evolvement of electrical impulses within the atrium.

Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation.

BACKGROUND: There are limited data comparing radiofrequency catheter ablation with antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation. METHODS: We randomly assigned 294 patients with paroxysmal atrial fibrillation and no history of antiarrhythmic drug use to an initial treatment strategy of either radiofrequency catheter ablation (146 patients) or therapy with class IC or class III antiarrhythmic agents (148 patients). Follow-up included 7-day Holter-monitor recording at 3, 6, 12, 18, and 24 months. Primary end points were the cumulative and per-visit burden of atrial fibrillation (i.e., percentage of time in atrial fibrillation on Holter-monitor recordings). Analyses were performed on an intention-to-treat basis. RESULTS: There was no significant difference between the ablation and drug-therapy groups in the cumulative burden of atrial fibrillation (90th percentile of arrhythmia burden, 13% and 19%, respectively; P=0.10) or the burden at 3, 6, 12, or 18 months. At 24 months, the burden of atrial fibrillation was significantly lower in the ablation group than in the drug-therapy group (90th percentile, 9% vs. 18%; P=0.007), and more patients in the ablation group were free from any atrial fibrillation (85% vs. 71%, P=0.004) and from symptomatic atrial fibrillation (93% vs. 84%, P=0.01). One death in the ablation group was due to a procedure-related stroke; there were three cases of cardiac tamponade in the ablation group. In the drug-therapy group, 54 patients (36%) underwent supplementary ablation. CONCLUSIONS: In comparing radiofrequency ablation with antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation, we found no significant difference between the treatment groups in the cumulative burden of atrial fibrillation over a period of 2 years. (Funded by the Danish Heart Foundation and others; MANTRA-PAF ClinicalTrials.gov number, NCT00133211.).

Symptomatic and asymptomatic atrial fibrillation after pulmonary vein ablation and the impact on quality of life.

BACKGROUND: The aim of this prospective study was to evaluate the recurrences of atrial fibrillation (AF) and flutter (AFL) after circumferential pulmonary vein ablation (CPVA) using repetitive long-term Holter recordings, and to evaluate the change in quality of life (QoL), especially in patients with asymptomatic AF recurrences. METHODS: A total of 149 patients with AF were followed up with 7-day Holter monitoring at 3, 6, and 12 months after CPVA. We calculated the burden of AF/AFL defined as the percentage of time in AF/AFL, and patients with documented arrhythmia were divided into isolated symptomatic episodes of arrhythmia, mixed symptomatic/asymptomatic arrhythmia, or isolated asymptomatic arrhythmia. The QoL was analyzed with SF-36 questionnaires in patients with sinus rhythm after CPVA, and in patients with recurrence of symptomatic and asymptomatic arrhythmia, respectively. RESULTS: Asymptomatic arrhythmia was observed in 44% of the patients with documented arrhythmia at 12 months of follow-up. In patients with persistent AF, 63% of the documented arrhythmia at 12 months of follow-up was asymptomatic and often persistent. In the subgroup of patients with asymptomatic arrhythmia, the QoL improved significantly in the physical scores, in contrast to patients with symptomatic arrhythmia who had unchanged or worsened QoL scores. CONCLUSIONS: Asymptomatic arrhythmia is very common after AF ablation. Our data indicate that these patients improve their physical component of the QoL significantly, which may be considered a palliative success of treatment. We suggest that patients with asymptomatic AF recurrences are carefully evaluated before considering reablation. Repetitive rhythm monitoring after AF ablation is very important considering the postablation management of anticoagulant therapy.

The Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) trial: clinical rationale, study design, and implementation.

AIMS: No large randomized multicentre trial has evaluated the efficacy of radiofrequency ablation (RFA) vs. anti-arrhythmic drug (AAD) therapy as a first-line treatment of paroxysmal atrial fibrillation (AF). METHODS AND RESULTS: The Medical ANtiarrhythmic Treatment or Radiofrequency Ablation (MANTRA-PAF) trial is a randomized, controlled, parallel group, multicentre study designed to test whether catheter-based RFA is superior to optimized AAD therapy in suppressing relapse within 24 months of symptomatic and/or asymptomatic AF in patients with paroxysmal AF without prior AAD therapy. The primary endpoint is cumulative AF burden on repeated 7 days Holter monitoring. Secondary endpoints are: thromboembolic events, hospitalization due to arrhythmia, pro-arrhythmic events, procedure/treatment-related side effects, health economics, quality of life, and change in left ventricular function. Ten centres in Scandinavia and Germany are participating in the study. Enrolment was started in 2005 and as of November 2008, 260 patients have been enrolled into the study. It is expected that enrolment will end by March 2009, when 300 patients have been included. CONCLUSION: The MANTRA-PAF trial will determine whether catheter-based RFA is superior to optimized AAD therapy as a first-line treatment in suppressing long-term relapse of symptomatic and/or asymptomatic AF.

[Frequent ventricular ectopy as reversible cause of dilated cardiomyopathy]. / Hyppig ventrikulaer ekstrasystoli som reversibel årsag til dilateret kardiomyopati.

Chronic arrhythmias may cause cardiomyopathy. We present two cases of severe cardiomyopathy in two young men with frequent monomorphic ventricular ectopy. In both cases radiofrequency ablation of a left ventricular ectopic focus led to normalization of cardiac function within months.

DDD(R)-pacing, but not AAI(R)-pacing induces left ventricular desynchronization in patients with sick sinus syndrome: tissue-Doppler and 3D echocardiographic evaluation in a randomized controlled comparison.

AIMS: Increasing evidence from randomized trials and experimental studies indicates that right ventricular (RV) pacing may induce congestive heart failure. We studied regional left ventricular (LV) dyssynchrony and global LV function in 50 consecutive patients with sick sinus syndrome (SSS) randomized to either atrial pacing [AAI(R)] or dual chamber RV-pacing [DDD(R)]. METHODS AND RESULTS: Fifty consecutive patients were randomized to AAI(R) or DDD(R)-pacing. Tissue-Doppler imaging was used to quantify LV dyssynchrony in terms of number of segments with delayed longitudinal contraction (DLC). Left ventricular ejection fraction (LVEF) was measured using three-dimensional echocardiography. Dyssynchrony was more pronounced in the DDD(R)-group than in the AAI(R)-group at the 12 months follow-up (P < 0.05). This reflected a significant increase of dyssynchrony in the DDD(R)-group from baseline to the 12 months follow-up (1.3 +/- 1 to 2.1 +/- 1 segments displaying DLC per patient), P < 0.05. No change was observed in the AAI(R)-group (1.6 +/- 2 to 1.3 +/- 2 segments displaying DLC per patient, NS). No difference in LVEF, NYHA or NT-proBNP was observed between AAI(R)- and DDD(R)-mode after 12 months of pacing although LVEF decreased significantly in the DDD(R)-group from baseline (63.1 +/- 8%) to the 12 months follow-up (59.3 +/- 8%, P < 0.05), while LVEF remained unchanged in the AAI(R)-group (61.5 +/- 11% at baseline vs. 62.3 +/- 7% after 12 months, NS. CONCLUSION: In patients with SSS, DDD(R)-pacing but not AAI(R)-pacing induces significant LV desynchronization and reduction of LVEF.

[Radio frequency of atrial fibrillation: results from 102 consecutive patients--secondary publication]. / Radiofrekvensablation af atrieflimren: resultater fra 102 konsekutive patienter--sekundaerpublikation.

Segmental pulmonary vein isolation (SPVI) and circumferential pulmonary vein isolation (CPVI) are the two main approaches to radiofrequency ablation in patients with atrial fibrillation (AF). The aim of this retrospective study was to investigate the safety level and patient outcome of both approaches. The overall freedom from symptoms was 73% and 25% after CPVI and SPVI, respectively. Our study concludes that CPVI is an effective treatment of highly symptomatic and drug-resistant AF and when used in laboratories by experienced electrophysiologists has a promising and reproducible outcome ratio and safety level.

Left ventricular lead performance in cardiac resynchronization therapy: impact of lead localization and complications.

INTRODUCTION: Cardiac resynchronization therapy (CRT) using left ventricular (LV) pacing from the coronary sinus tributary is increasingly and frequently used in patients with severe congestive heart failure. The present study investigates LV lead performance in different anatomic locations. METHODS: The LV pacing site was defined by bi-plane fluoroscopy. In the left anterior oblique view, the coronary sinus is encircling the mitral ring with the tributaries radiating out like the hands of a watch. Using this clockwise method, Group A had an LV pacing site before 3 o'clock and Group B at or after 3 o'clock. In right anterior oblique view, the LV was divided into three segments: basal, mid-ventricular, and apical. RESULTS: LV lead implantation was successful in all of 120 consecutive patients. Mean follow-up was 16.7 months. Implantation time decreased from mean 190 to 80 minutes during the period (P = 0.01). The mean LV lead stimulation threshold increased initially and stabilized afterwards. The threshold measured at last follow-up was higher than at implantation (2.3 vs 2.7 microJ, P = 0.04). Useful venograms were obtained in 94 patients. No significant difference in thresholds was observed between Groups A and B. Phrenic nerve stimulation was most commonly seen in Group B (8/70 vs 1/24, P = 0.001). CONCLUSION: Implantation of an LV lead for CRT is possible in patients with congestive heart failure and associated with an acceptable low complication rate. LV lead implantation is associated with a learning curve. At mid-term follow-up, LV lead performance is stable and unrelated to the LV implantation site.