Antiarrhythmic Drug Therapy after Radiofrequency Catheter Ablation in Patients with Atrial Fibrillation

Objectives: The use of antiarrhythmic drugs after ablation is a controversial issue when evaluating the efficacy of atrial fibrillation (AF) ablation. This study compares in a prospective and randomized fashion the impact of an antiarrhythmic drug in preventing AF recurrence after AF ablation.
Methods: From February 2004 to May 2005, 107 consecutive patients (mean age 57 ± 10 years, 69 men), with paroxysmal (60%) or persistent (40%) drug refractory AF, were randomly assigned to ablation alone (Group A, 53 patients) or combined with the best antiarrhythmic therapy, preferably amiodarone (Group B, 54 patients). All patients underwent cavo-tricuspid and left inferior pulmonary vein (PV)-mitral isthmus ablation plus circumferential PV ablation, using a guided electro-anatomical approach. Standard electrocardiograms (ECG), and ambulatory and transtelephonic ECG monitoring were used to assess AF recurrences. Recurrences during the first month after ablation were excluded from this analysis.
Results: At 12 months of follow-up, no significant difference was observed in the rates of AF recurrences between Group A (18/53 patients, 34%) and Group B (16/54 patients, 30%). The percentage of patients with ≥1 asymptomatic AF episode was higher in Group B than in Group A (10/16 patients, 63%, vs 5/18 patients, 28%, P = 0.04).
Conclusions: Continuing antiarrhythmic drug therapy in patients who undergo catheter ablation for AF did not lower the rate of AF recurrences. Antiarrhythmic drugs increased the proportion of patients with asymptomatic AF episodes.     

Significant Left Atrial Appendage Activation Delay Complicating Aggressive Septal Ablation during Catheter Ablation of Persistent Atrial Fibrillation

Background: This study aims to describe significant left atrial appendage activation following ablation of persistent atrial fibrillation, and explore its relationship with aggressive septal ablation. Methods and Results: Significant left atrial appendage activation delay was found in 23 out of 201 patients undergoing persistent atrial fibrillation ablation. Of them, 14 were found in their index procedures, of whom septal line ablation was performed in nine (odds ratio 15.2, 95% confidence interval 4.6–50.8, P < 0.001). Another nine were found during their redo procedures (including two with biatrial activation dissociation), all of whom received extensive left septal complex fractionated electrograms ablation in their prior procedures (P = 0.002). Electrocardiograph showed split P wave with the latter component merged into the QRS wave. Activation mapping demonstrated the earliest breakthrough of the left atrium changed to coronary sinus in 18 (85.7%) patients. After 1 month, the mitral A wave velocity was 18.2 ± 17.0 cm/s, and decreased significantly as compared with preablation (20.2 ± 19.1 vs 58.2 ± 17.9 cm/s, P = 0.037) in patients undergoing redo procedures. Fourteen (60.9%) remained arrhythmia‐free during follow‐up for 10.6 ± 6.2 months. Conclusion: Septal line ablation and extensive septal complex fractionated electrograms ablation are correlated with significant left atrial activation delay or even biatrial activation dissociation, and should be performed with prudent consideration. (PACE 2010; 33:652–660)     

Predictive Capability of Left Atrial Size Measured by CT,TEE, and TTE for Recurrence of Atrial Fibrillation Following Radiofrequency Catheter Ablation

Background: Recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) has been well established and is in part related to left atrial (LA) size. The purpose of this study was to assess the predictive capability of LA diameter (LAD) and LA volume (LAV) by echocardiography and computed tomography (CT) to determine success in patients undergoing RFCA of AF. Methods: Eighty‐eight patients with paroxysmal or persistent AF who had undergone RFCA and had a prior transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), and CT were enrolled in the study. TTE LADs and LV ejection fraction as well as TEE LADs and LAVs in three views were recorded. CT LAVs were also recorded. Clinical parameters prior to ablation as well as at 1‐year follow‐up were assessed. Results: A total of 40 (45%) patients with paroxysmal AF and 48 (55%) patients with persistent AF were analyzed. Paroxysmal AF patients had a RFCA success rate of 88% at 1 year with persistent AF patients having a 52% success rate (P < 0.001). A CT‐derived LAV ≥ 117 cc was associated with an odds ratio (OR) for recurrence of 4.8 (95% confidence interval [CI]=[1.4–16.4], P = 0.01) while a LAV ≥130 cc was associated with an OR for recurrence of 22.0 (95% CI =[2.5–191.0], P = 0.005) after adjustment for persistent AF. Conclusions: LA dimensions and AF type are highly predictive of AF recurrence following RFCA. LAV by CT has significant predictive benefit over standard LADs in severely enlarged atria even after adjustment for AF type. (PACE 2010; 532–540)     

Catheter Ablation for Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in adults, and its prevalence is on the rise. Catheter ablation of AF, once considered a novel procedure, has become the most commonly performed technique for treating patients with severe symptomatic AF. This article reviews the latest American Heart Association/American College of Cardiology/Heart Rhythm Society guideline on the indications for AF and summarizes techniques available to achieve freedom of recurrent arrhythmia and relief from symptoms. Nurse practitioners need to provide guideline-directed care before, during, and after catheter ablation to improve patients’ quality of life and prevent complications.     

Catheter Ablation versus Standard Conventional Treatment in Patients with Left Ventricular Dysfunction and Atrial Fibrillation (CASTLE-AF) - Study Design

Background: Electrical isolation of the pulmonary veins by catheter ablation is an emerging treatment modality for the treatment of atrial fibrillation (AF) and is increasingly used in patients with heart failure.
Methods: The catheter ablation versus standard conventional treatment in patients with left ventricular dysfunction and atrial fibrillation trial (CASTLE-AF) is a randomized evaluation of ablative treatment of atrial fibrillation in patients with left ventricular dysfunction. The primary endpoint is the composite of all-cause mortality or worsening of heart failure requiring unplanned hospitalization using a time to first event analysis. Secondary endpoints are all-cause mortality, cardiovascular mortality, cerebrovascular accidents, worsening of heart failure requiring unplanned hospitalization, unplanned hospitalization due to cardiovascular reason, all-cause hospitalization, quality of life, number of therapies (shock and antitachycardia pacing) delivered by the implantable cardioverter-defibrillator (ICD), time to first ICD therapy, number of device-detected ventricular tachycardia and ventricular fibrillation episodes, AF burden, AF free interval, left ventricular function, exercise tolerance, and percentage of right ventricular pacing. CASTLE-AF will randomize 420 patients for a minimum of 3 years at 48 sites in the United States, Europe, Australia, and South America.     

Cost Analysis of Catheter Ablation for Paroxysmal Atrial Fibrillation

WEERASOORIYA, R., et al. : Cost Analysis of Catheter Ablation for Paroxysmal Atrial Fibrillation . RF ablation for paroxysmal atrial fibrillation (PAF) is a curative treatment, which when successful, eliminates the need to take antiarrhythmic drugs, be anticoagulated, and have recurrent physician visits or hospital admissions. The authors performed a retrospective cost comparison of RF ablation versus drug therapy for PAF. The study population consisted of 118 consecutive patients with symptomatic, drug refractory PAF who underwent   1.52 ± 0.71   RF ablation procedures (range 1–4) for PAF. During a follow-up of 32 ± 15 weeks, 85 (72%) patients remained free of clinical recurrence in absence of antiarrhythmic drugs. The cost of RF ablation was calculated in the year 2001 euros on the basis of resource use. The mean cost of pharmacologic treatment prior to ablation was 1,590 euros/patient per year. The initial cost of RF ablation for PAF was 4,715 euros, then 445 euros/year. After 5 years, the cost of RF ablation was below that of ongoing medical management, and continued to diverge thereafter. RF catheter ablation may be a cost-effective alternative to long-term drug therapy in patients with symptomatic, drug refractory PAF. (PACE 2003; 26[Pt. II]:292–294)     

持续性心房颤动导管消融术强化间隔消融与术后左心耳激动延迟的关系

  目的  探讨持续性心房颤动(简称房颤)导管消融术后左心耳激动显著延迟与术中强化间隔消融的关系。  方法  对2007年6月至2009年2月在本科接受导管消融术的201例持续性房颤患者行步进式导管消融, 术后行左房激动标测并记录左心耳电活动, 术后1月行经胸心脏超声评估左房功能。  结果  术后23例出现左心耳激动显著延迟, 其中14例为初次消融病例, 9例接受了间隔线消融(OR 15.2, 95%CI 4.6~50.8, P < 0.001);另9例为第2次消融(包括2例左房隔离)病例, 9例患者也于初次消融中行广泛间隔复杂碎裂电位消融(P=0.002)。激动标测提示21例患者中18例(85.7%)左房最早激动部位转向冠状窦。术后1个月二尖瓣前向血流A峰为(18.2±17.0)cm/s, 与术前为窦性心律者比较显著下降, (20.2±19.1)cm/s vs.(58.2±17.9)cm/s(P=0.037)。随访(10.6±6.2)个月, 14例患者维持窦性心律。  结论  持续性房颤导管消融术行间隔线或广泛间隔复杂碎裂电位消融可导致左心耳激动显著延迟, 可能影响左房功能, 持续性房颤患者采用此术式应该慎重。     

Anatomy-Guided Linear Atrial Lesions for Radiofrequency Catheter Ablation of Atrial Fibrillation

The surgical atrial maze procedure has provided proof that atrial fibrillation can be cured by performing atrial incisions based on anatomical and electrophysiological principles. Preliminary reports of attempts at radio frequency catheter ablation of atrial fibrillation utilizing an anatomy-based "linear incision" method have shown the feasibility of the method. However, postprocedural atrial fibrillation recurrence has been common and in addition new, uniform tachycardias have developed in some patients. Both of these outcomes may be in part due to incomplete or inconsistent lesion deployment. This article details the use of the CARTO system for deploying anatomy guided linear atrial lesions for the purpose of curing atrial fibrillation. The procedure is comprised of three phases, which are discussed in detail: (1) baseline map: (2) lesion deployment and; (3) lesion assessment. Using a single standard ablation electrode, lesions can be deployed safely, and complete lesions can be confirmed. Paradigms for right and left atrial incisions are proposed.     

Contemporary Challenges of Catheter Ablation for Atrial Fibrillation

Purpose

Catheter ablation of atrial fibrillation (AF) is now one of the most frequently performed ablation procedures, but there are currently 2 important challenges: achieving permanent/durable rather than transient pulmonary vein isolation (PVI) and improving the results of ablation for the wider patient population with persistent AF.

Methods

Recent technical advances in the technique of ablation and the results of clinical trials aimed at achieving more permanent and durable PVI are reviewed. We also summarize recent advances in identifying atrial fibrosis and in understanding the pathophysiology of AF relevant to selecting patients for ablation of persistent AF.

Findings

The use of contact force–sensing technology, adenosine testing after ablation, and pace capture–guided ablation all have the potential for achieving more durable ablation. Selection of patients suitable for ablation of persistent AF may be improved by assessing the extent of atrial fibrosis with delayed enhancement imaging with cardiac magnetic resonance or by assessing the pattern of atrial electrical activity with the use of complex atrial electrograms. Advances in treatment are likely to result from the recognition of localized rotors and focal sources as primary sustaining mechanisms for all types of human AF and in the use of noninvasive mapping for their identification. Linear ablation to supplement PVI may improve the results of AF ablation.

Implications

Rapidly unfolding advances in the techniques of AF ablation and the understanding of mechanisms of AF hold promise for improving the durability of PVI and for extending the technique to carefully selected patients with persistent AF.     

经导管射频消融治疗阵发性心房颤动临床研究

[目的]探讨经导管射频消融治疗阵发性心房颤动的有效性与安全性.[方法]60例阵发性心房颤动患者药物治疗无效且反复发作,采用节段性消融肺静脉电隔离术、CARTO和EnSite 3000三维空间标测系统指导下肺静脉电隔离术3种不同的方法进行肺静脉电位经导管射频消融隔离治疗,术后随访3～41个月.[结果]60例患者中42例(70.0%)经消融成功,10例(16.7%)有效,8例(13.3%)失败,无严重并发症;CARTO和EnSite 3000三维空间标测系统指导肺静脉电隔离术可明显减少X线曝光时间.[结论]经导管射频消融治疗局灶性心房颤动是可行的,对大部分患者是有效的.     

Prevalence and Characteristics of Left Atrial Tachycardia Following Left Atrial Catheter Ablation

Background: Left atrial tachycardia (AT) is a complication of left atrial catheter ablation (LACA) of atrial fibrillation (AF). However, its prevalence and characteristics have not been sufficiently clarified.
Methods: We divided 121 patients who underwent LACA into 2 groups based on the results of AT occurrence after LACA (follow-up period; 12 ± 7 months): an AT+ group and AT– group.
Results: New-onset left AT occurred in 30 patients (25%) 31 ± 51 days after LACA. Among the 26 patients with an early onset of AT, 4 underwent a second ablation for AT, and 21 became free of AT within 6 months without a repeat ablation procedure. Among the 4 patients with a late onset of AT (>2 months after the LACA), the tachycardia remitted without a repeat ablation procedure in a single patient within 6 months. Among 71 patients who underwent LACA with additional ablation lines, 22 (31%) developed new-onset left AT. Among 50 patients who underwent LACA alone, 8 (16%) developed new-onset left AT (P = 0.02).
Conclusions: New-onset left AT is a frequent complication of LACA for AF, especially in men and in patients with a low left ventricular ejection fraction. Early (<2 months) onset AT does not require a repeat ablation because it often represents a transient phenomenon and disappears spontaneously.     

Relation Between Left Atrial Size and Secondary Atrial Arrhythmias After Successful Catheter Ablation of Common Atrial Flutter

Catheter ablation ptovides an effective cure for patients with typical atrial flutter. However, these patients may have the potential to develop atrial tachyarrhythmias other than common atrial flutter. This study examines clinical and echocardiographic predictors for the occurrence of uncommon atrial flutter or atrial fibrillation after abolition of common atrial flutter. The study population comprised 17 patients (12 men, 5 women, age 32–74 years) who underwent successful radiofrequency catheter ablation of common atrial flutter. Common atrial flutter did not recur in any patient during a median follow-up time of 8 (range 1–25) months. Within a median of 7 (range 1–223) days, however, symptomatic atrial tachyarrhythmias occurred in 8 of 17 patients (47%): uncommon atrial flutter (n = 4); atrial fibrillation (n = 3); and both uncommon atrial flutter and atrial fibrillation in one patient. Preablation left atrial volume was significantly larger in patients who developed secondary arrhythmias compared with patients who remained in sinus rhythm (57.9 ± 15.6 vs 43.7 ± 16.4 cm³, P < 0.05). Enlarged left atrial volume dichotomized at 51 cm³ independently predicted postablation atrial arrhythmias (x²=5.11, rel. risk = 5.3, P < 0.05). On Kaplan-Meier analysis, time to occurrence of postablation atrial arrhythmias was significantly shorter in patietits with enlarged left atrium (P < 0.02). In conclusion, symptomatic uncommon atrial flutter and atrial fibrillation develops in a substantial proportion of patients after successful ablation of common atrial flutter. Out of a series of clinical and echocardiographic parameters, preablation left atrial size is the best predictor for the occurrence of these postablation atrial arrhythmias.     

Early Experience with Robotic Navigation for Catheter Ablation of Paroxysmal Atrial Fibrillation

Introduction: Pulmonary venous antra isolation (PVAI) is the cornerstone of catheter ablation procedure for drug refractory paroxysmal atrial fibrillation (AF). However, the procedure is technically challenging. Robotic navigation has a potential to expedite and facilitate the procedure.
Methods: A robotic catheter control system was used for remote navigation-supported PVAI in 22 patients (mean age = 55 ± 9 years, 16 males, study group). An irrigated-tip catheter with estimate of catheter force on the tissue was used. This was compared in nonrandomized fashion with conventional hand-controlled catheter ablation in 16 patients (mean age = 55 ± 9 years, 13 males, control group). The procedures were performed under guidance of Ensite NavX navigation system (St. Jude Medical, St. Paul, MN, USA) and intracardiac echocardiography.
Results: Robotic navigation was associated with significantly shorter overall duration of radiofrequency delivery (1,641 ± 609 vs 2,188 ± 865 seconds, P < 0.01), shorter total procedural time (207 ± 29 vs 250 ± 62 minutes, P = 0.007), fluoroscopy exposure (15 ± 5 vs 27 ± 9 minutes, P < 0.001), and lower radiation dose (1,119 ± 596 vs 3,048 ± 2,029 mGy/m², P < 0.001). No complication was observed in either the study or the control group. During the 5 ± 1 months follow-up in the study group and 9 ± 3 months in the control group, 91% and 81% of patients, respectively, were AF free.
Conclusions: In our early clinical experience, PVAI using a remote robotic catheter navigation was effective, safe, and associated with shorter procedural and fluoroscopic times than conventional PVAI.     

Radiation Exposure During Radiofrequency Catheter Ablation for Atrial Fibrillation

MACLE, L., et al. : Radiation Exposure During Radiofrequency Catheter Ablation for Atrial Fibrillation. RF catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with prolonged fluoroscopy. The procedural duration and fluoroscopic exposure to patients and medical staff were recorded and compared among 43 ablation procedures for PAF, 20 for common atrial flutter, and 16 for accessory pathways. Patient radiation exposure was measured by dosimeters placed over the xyphoid, while that of physicians and nurses was measured by dosimeters placed outside and inside the lead apron. The mean fluoroscopy time was   57 ± 30   minutes for PAF,   20 ± 10   minutes for common flutter, and   22 ± 21   minutes for accessory pathway ablation. The patient median radiation exposure was 1110μSv for PAF, compared with 500 μSv for common flutter and 560 μSv for accessory pathway ablation (P < 0.01). The median radiation exposure to physician and nurse inside the lead apron were, respectively, 2 μSv and 3 μSv for PAF, 1 μSv and 2 μSv for common flutter, and <0.5 μSv and 3 μSv for accessory pathway ablations. RF catheter ablation for PAF was associated with prolonged fluoroscopy times and a twofold higher radiation exposure to the patient and physician compared with other ablation procedures. Assuming 300 procedures/year, radiation exposure to the medical staff was below the upper recommended annual dose limit. (PACE 2003; 26[Pt. II]:288–291)     

Catheter Ablation of Chronic Atrial Fibrillation with Noncontact Mapping:

SEIDL, K., et al .: Catheter Ablation of Chronic Atrial Fibrillation with Noncontact Mapping: Are Continuous Linear Lesions Associated with Ablation Success? Catheter-based, right and left atrial compartmentalization procedure was evaluated using a noncontact mapping (NCM) system. Its usefulness to identify and close discontinuities in linear lesions in both atria was evaluated. The impact of linear lesion continuity on ablation success of chronic AF was also investigated. Nineteen patients with symptomatic, drug refractory chronic AF were studied. Right atrial ablation with three predefined lines was attempted in all patients. In 18 patients, left atrial ablation was performed with four linear lesions. During a follow-up of 12 ± 3 months , 6 of 19 patients remained in sinus rhythm (SR) without antiarrhythmic agents (AAs). In addition, four patients were maintained in SR with AA. Thirteen of 14 patients with gaps identified during off-line analysis had recurrence of AF. Only one patient with a gap was free of recurrence without AAs. In the remaining five patients without recurrence of AF, no gap was observed during off-line analysis. In all four patients who were free of AF with additional treatment of AAs, two gaps had been identified. In the remaining nine patients with chronic AF recurrence, a mean of 4.9 gaps were identified. Excluding the initial learning period (first five patients) the success rate increased to 43% (6/14 patients) without and to 71% (10/14 patients) with AA. NCM identifies discontinuities in lines of ablation. Successful ablation of chronic AF is associated with continuity of linear lesions and good clinical technique demands a vigilant search for and closure of every gap. (PACE 2003; 26[Pt. I]:534–543)