Complex electrograms within the coronary sinus: time- and frequency-domain characteristics, effects of antral pulmonary vein isolation, and relationship to clinical outcome in patients with paroxysmal and persistent atrial fibrillation

Background: The mechanistic and clinical significance of complex fractionated atrial electrograms (CFAE) in the coronary sinus (CS) has been unclear. Methods and Results: Antral pulmonary vein isolation (APVI) was performed in 77 patients with paroxysmal (32) or persistent AF (45). CS electrograms recorded for 60 seconds before and after APVI were analyzed in the time‐ and frequency‐domains. Dominant frequency (DF), complexity index (CI: change in polarity of depolarization), and fractionation index (FI: change in direction of depolarization slope) were determined. Before APVI, there was no difference in DF, CI, or FI between paroxysmal and persistent AF. APVI resulted in a significant decrease in DF, CI, and FI in all patients. Baseline CI (43 ± 13/s vs 54 ± 14/s, P = 0.03) and FI (64 ± 23/s vs 87 ± 30/s, P = 0.02) were lower in patients with paroxysmal AF who had AF terminated by ablation than who did not. At 10 ± 2 months, 69% of patients with paroxysmal AF and 49% of patients with persistent AF were free from AF after single ablation. Baseline CI was higher among patients with paroxysmal AF who had AF after APVI (56 ± 20/s vs 44 ± 10/s, P = 0.03). In patients with persistent AF, there was a larger decrease in DF after APVI among patients who remained free from AF (13 ± 11% vs 7 ± 9%, P < 0.05). Conclusions: Complexity of CS electrograms may reflect drivers of AF that perpetuate paroxysmal AF after APVI. In persistent AF, the extent to which APVI decreases DF in the CS correlates with efficacy, suggesting that DF identifies patients who may require additional ablation beyond APVI.     

Anticoagulant therapy and risk of cerebrovascular events after catheter ablation of atrial fibrillation in the elderly

Stroke and Atrial Fibrillation Ablation . Introduction: Factors associated with cerebrovascular events (CVEs) after radiofrequency catheter ablation (RFA) of atrial fibrillation (AF) have not been well defined in elderly patients (≥65 years). The purpose of this study was to determine the prevalence and predictors of CVEs after RFA in patients with AF ≥65 years old, in comparison to patients <65 years, and with or without AF. Methods and Results: This study included 508 consecutive patients ≥65 years old (mean age: 70 ± 4 years), who underwent RFA for paroxysmal (297) or persistent (211) AF. A stratified group of 508 patients < 65 years old who underwent RFA for AF served as a control group. All patients were anticoagulated with warfarin for ≥3 months after RFA. A perioperative CVE (≤4 weeks after RFA) occurred in 0.8% and 1% of patients ≥65 and <65 years old, respectively (P = 1). Among the patients ≥65 years old who remained in sinus rhythm after RFA, warfarin was discontinued in 60% and 56% of the patients with a CHADS₂ score of 0 and ≥1, respectively. Paroxysmal AF, no history of CVE, and successful RFA were independent predictors of discontinuing warfarin. During a mean follow‐up of 3 ± 2 years, a late CVE (>4 weeks after the RFA) occurred in 15 of 508 (3%) of patients ≥65 years old (1% per year) and in 5 of 508 (1%) patients <65 years old (0.3% per year, P = 0.03). Among patients ≥65 years old, age >75 years old (OR = 4.9, ±95% CI: 3.3–148.5, P = 0.001) was the only independent predictor of a CVE. Among patients <65 years old, body mass index was the only independent predictor of a late CVE (OR = 1.2, ±95% CI: 1.03–1.33, P = 0.02). Conclusions: The risk of a periprocedural CVE after RFA of AF is similar among patients ≥65 and <65 years old. Late CVEs after RFA are more prevalent in older than younger patients with AF, and age >75 years old is the only independent predictor of late CVEs regardless of the rhythm, anticoagulation status, or the CHADS₂ score (Congestive heart failure, Hypertension, Age ≥ 75 years, Diabetes mellitus and prior Stroke or transient ischemic attack). (J Cardiovasc Electrophysiol, Vol. 23, pp. 36‐43, January 2012)     

Prevalence and predictors of complications of radiofrequency catheter ablation for atrial fibrillation

Complications of Atrial Fibrillation Ablation. Introduction: Up to 6% of patients experience complications after radiofrequency catheter ablation (RFA) of atrial fibrillation (AF). The purpose of this study is to determine the prevalence and predictors of periprocedural complications after RFA for AF. Methods and Results: The subjects were 1,295 consecutive patients (age = 60 ± 10 years) who underwent RFA (n = 1,642) for paroxysmal (53%) or persistent AF (47%) from January 2007 to January 2010. A complication occurred in 57 patients (3.5%); a vascular access complication in 31 (1.9%); pericardial tamponade in 20 (1.2%); a thromboembolic event in 4 (0.2%); deep venous thrombosis in 1 (<0.01%); and pulmonary vein stenosis in 1 patient (<0.01%). There were no procedure‐related deaths. On multivariate analysis, female gender (OR = 2.27; ±95% CI: 1.31–2.57, P < 0.01) and procedures performed in July or August (OR = 2.10; ±95% CI: 1.16–3.80, P = 0.01) were independent predictors of any complication. For vascular complications, treatment with clopidogrel (OR = 4.40; ±95% CI: 1.43–13.53, P = 0.01), female gender (OR = 3.65; ±95% CI: 1.72–7.75, P < 0.01) and performing RFA in July or August (OR = 2.71; ±95% CI: 1.25–5.87, P = 0.01) were independent predictors. The only predictor of cardiac tamponade was prior RFA (OR = 3.32; ±95% CI: 0.95–11.61; P < 0.05). Conclusion: Prevalence of perioperative complications for RFA of AF is 3.5% and vascular access complications constitute the majority. The need for clopidogrel therapy should be carefully considered prior to RFA. At teaching institutions close supervision should be exercised during vascular access early in the year. Improvements in ablation technology and elimination of the need for repeat procedures may decrease the risk of pericardial tamponade . (J Cardiovasc Electrophysiol, Vol. 22, pp. 626‐631, June 2011)     

Impact of Pharmacological Autonomic Blockade on Complex Fractionated Atrial Electrograms

Autonomic Blockade During Atrial Fibrillation . Introduction: The influence of the autonomic nervous system on the pathogenesis of complex fractionated atrial electrograms (CFAE) during atrial fibrillation (AF) is incompletely understood. This study evaluated the impact of pharmacological autonomic blockade on CFAE characteristics. Methods and Results: Autonomic blockade was achieved with propanolol and atropine in 29 patients during AF. Three‐dimensional maps of the fractionation degree were made before and after autonomic blockade using the Ensite Navx^® system. In 2 patients, AF terminated following autonomic blockade. In the remaining 27 patients, 20,113 electrogram samples of 5 seconds duration were collected randomly throughout the left atrium (10,054 at baseline and 10,059 after autonomic blockade). The impact of autonomic blockade on fractionation was assessed by blinded investigators and related to the type of AF and AF cycle length. Globally, CFAE as a proportion of all atrial electrogram samples were reduced after autonomic blockade: 61.6 ± 20.3% versus 57.9 ± 23.7%, P = 0.027. This was true/significant for paroxysmal AF (47 ± 23% vs 40 ± 22%, P = 0.003), but not for persistent AF (65 ± 22% vs 62 ± 25%, respectively, P = 0.166). Left atrial AF cycle length prolonged with autonomic blockade from 170 ± 33 ms to 180 ± 40 ms (P = 0.001). Fractionation decreases only in the 14 of 27 patients with a significant (>6 ms) prolongation of the AF cycle length (64 ± 20% vs 59 ± 24%, P = 0.027), whereas fractionation did not reduce when autonomic blockade did not affect the AF cycle length (58 ± 21% vs 56 ± 25%, P = 0.419). Conclusions: Pharmacological autonomic blockade reduces CFAE in paroxysmal AF, but not persistent AF. This effect appears to be mediated by prolongation of the AF cycle length. (J Cardiovasc Electrophysiol, Vol. pp. 766‐772, July 2010)     

Reversal of pulmonary vein remodeling after catheter ablation of atrial fibrillation

Background Pulmonary veins (PV) and the atria undergo electrical and structural remodeling in atrial fibrillation (AF). This study aimed to determine PV and left atrial (LA) reverse remodeling after catheter ablation for AF assessed by chest computed tomography (CT). Methods PV electrophysiologic studies and catheter ablation were performed in 63 patients (68% male; mean ± SD age: 56 ± 10 years) with symptomatic AF (49% paroxysmal, 51% persistent). Chest CT was performed before and 3 months after catheter ablation. Results At baseline, patients with persistent AF had a greater LA volume (91 ± 29 cm³ vs. 66 ± 27 cm3; P = 0.003) and mean PV ostial area (241 ± 43 mm² vs. 212 ± 47 mm²; P = 0.03) than patients with paroxysmal AF. There was no significant correlation between the effective refractory period and the area of the left superior PV ostium. At 3 months of follow-up after ablation, 48 patients (76%) were AF free on or off antiar?rhythmic drugs. There was a significant reduction in LA volume (77 ± 31 cm³ to 70 ± 28 cm³; P < 0.001) and mean PV ostial area (224 ± 48 mm² to 182 ± 43 mm²; P < 0.001). Patients with persistent AF had more reduction in LA volume (11.8 ± 12.8 cm³ vs. 4.0 ± 11.2 cm³; P = 0.04) and PV ostial area (62 mm² vs. 34 mm²; P = 0.04) than those who have paroxysmal AF. The reduction of the averaged PV ostial area was significantly correlated with the reduction of LA volume (r = 0.38, P = 0.03). Conclusions Catheter ablation of AF improves structural remodeling of PV ostia and left atrium. This finding is more apparent in patients with persistent AF treated by catheter ablation.     

Progression of late postoperative atrial fibrillation in patients with tetralogy of Fallot

1 Introduction

ToF patients are at risk for ventricular deterioration at a relatively young age, which can be aggravated by AF development. Therefore, knowledge on AF development and its timespan of progression is essential to guide treatment strategies for AF.

2 Objective

We examined late postoperative AF onset and progression in ToF patients during long‐term follow‐up after ToF correction. In addition, coexistence of AF with regular supraventricular tachyarrhythmias (SVT) and ventricular tachyarrhythmias (VTA) was analyzed.

3 Methods and results

ToF patients (N  =  29) with AF after ToF correction referred to the electrophysiology department between 2000 and 2015 were included. All available rhythm registrations were reviewed for AF, regular SVT, and VTA. AF progression was defined as transition from paroxysmal AF to (longstanding) persistent/permanent AF or from (longstanding) persistent AF to permanent AF. At the age of 44 ± 12 years, ToF patients presented with paroxysmal (N  =  14, 48%), persistent (N  =  13, 45%) or permanent AF (N  =  2, 7%). Age of AF development was similar among patients who either underwent initial shunt creation (N  =  15, 45 ± 11 [25–57] years) or primary total ToF correction (N  =  14, 43 ± 13 [26–66] years) (P  =  0.785). AF coexisted with regular SVT (N  =  18, 62%) and VTA (N  =  13, 45%). Progression of AF occurred in 11 patients (38%) within 5 ± 5 years after AF onset despite antiarrhythmic drug class II (AAD, P  =  0.052) or III (P  =  0.587) usage.

4 Conclusions

AF in our ToF population developed at a young age and showed rapid progression. Rhythm control by pharmacological therapy was ineffective in preventing AF progression.     

Time to Cardioversion of Recurrent Atrial Arrhythmias After Catheter Ablation of Atrial Fibrillation and Long‐Term Clinical Outcome

Introduction: It is unclear whether early restoration of sinus rhythm in patients with persistent atrial arrhythmias after catheter ablation of atrial fibrillation (AF) facilitates reverse atrial remodeling and promotes long‐term maintenance of sinus rhythm. The purpose of this study was to determine the relationship between the time to restoration of sinus rhythm after a recurrence of an atrial arrhythmia and long‐term maintenance of sinus rhythm after radiofrequency catheter ablation of AF. Methods and Results: Radiofrequency catheter ablation was performed in 384 consecutive patients (age 60 ± 9 years) for paroxysmal (215 patients) or persistent AF (169 patients). Transthoracic cardioversion was performed in all 93 patients (24%) who presented with a persistent atrial arrhythmia: AF (n = 74) or atrial flutter (n = 19) at a mean of 51 ± 53 days from the recurrence of atrial arrhythmia and 88 ± 72 days from the ablation procedure. At a mean of 16 ± 10 months after the ablation procedure, 25 of 93 patients (27%) who underwent cardioversion were in sinus rhythm without antiarrhythmic therapy. Among the 46 patients who underwent cardioversion at ≤30 days after the recurrence, 23 (50%) were in sinus rhythm without antiarrhythmic therapy. On multivariate analysis of clinical variables, time to cardioversion within 30 days after the onset of atrial arrhythmia was the only independent predictor of maintenance of sinus rhythm in the absence of antiarrhythmic drug therapy after a single ablation procedure (OR 22.5; 95% CI 4.87–103.88, P < 0.001). Conclusion: Freedom from AF/flutter is achieved in approximately 50% of patients who undergo cardioversion within 30 days of a persistent atrial arrhythmia after catheter ablation of AF.     

Comparison of left atrial electrophysiologic abnormalities during sinus rhythm in patients with different type of atrial fibrillation

Objective

The purpose of this study is to explore the left atrium (LA) electrophysiologic abnormalities in atrial fibrillation (AF) patients detected during sinus rhythm and to determine the relationship between the type of AF and the electrophysiologic substrate in the LA.

Methods

Eighty patients with AF (30 paroxysmal AF, 22 persistent AF, and 28 long-standing AF) and 20 age- and sex-matched patients with left-sided accessory pathway were prospectively studied. High-density three-dimensional electroanatomic mapping was performed during sinus rhythm in LA, which was divided into six segments for regional analysis. Mean bipolar voltage, low voltage zone (LVZ) distribution, LA activation time, and electrogram complexity were assessed.

Results

The LA mean voltage was 3.67?±?0.68 mV in no AF group, 2.16?±?0.63 mV in the paroxysmal, 1.81?±?0.36 mV in the persistent, and 1.48?±?0.34 mV in the long-standing AF patients (P?<?0.001). The total LA activation time was 75.3?±?5.4 ms in no AF, 89.7?±?12.3 ms in paroxysmal AF, 104.9?±?6.1 ms in persistent AF, and 115.6?±?12.1 ms in the long-standing AF patients, respectively (P?<?0.001). With the progression of AF, there was a higher incidence of LVZ detection and increased prevalence of complex electrograms with 95 % of complex electrograms in areas with the bipolar voltage ≤?1.3 mV in persistent and long-standing AF patients.

Conclusion

Patients with AF have abnormal electrophysiologic substrate in sinus rhythm characterized by lower mean bipolar voltage, more prevalent complex electrograms, and longer LA activation time. This substrate progresses parallel to progression of AF type.     

心房颤动转归 HATCH 评分系统的综合评价

HATCH 评分代表高血压病、年龄、脑缺血事件、慢性阻塞性肺疾病、心力衰竭对房颤进展的影响,适用于评估一年内阵发性房颤进展为持续性房颤的风险。近年来关于 HATCH评分对房颤转归预测价值的研究成为临床热点之一,许多研究表明,HATCH 评分与房颤射频消融术后复发及电复律转为窦律后复发有关,这些提示 HATCH 评分对于房颤的转归有重要的预测价值。本综述总结了近年来 HATCH 评分对于房颤转归的综合评价方面的研究进展。     

Approach to the catheter ablation technique of paroxysmal and persistent atrial fibrillation: a meta-analysis of the randomized controlled trials

Review of the Catheter Ablation Technique in AF. Background: Several randomized controlled trials (RCTs) have been published to investigate the optimal techniques for atrial fibrillation (AF) ablation. Many of these are small in number and include both paroxysmal and persistent AF; however, the techniques for each of these types of AF may differ. Method and Results: We searched MEDLINE, EMBASE, and the Cochrane Controlled Trials Register for RCTs evaluating AF ablation for either paroxysmal or persistent AF. The primary endpoint was freedom from AF after a single procedure. A total of 35 unique randomized controlled trials were found to fulfill the criteria. A significant degree of heterogeneity was present given the differing sample sizes, populations studied, and outcomes. Radiofrequency ablation (RFA) was found to be favorable in prevention of AF over antiarrhythmic drugs (AADs) in either paroxysmal (5 studies, RR 2.26; 95% CI 1.74, 2.94) or persistent AF (5 studies, RR 3.20; 95% CI 1.29, 8.41). When comparing specific techniques, wide‐area PVI appeared to offer the most benefit for both paroxysmal (6 studies, RR 0.78; 95% CI 0.63, 0.97) and persistent AF (3 studies, RR 0.64; 95% CI 0.43, 0.94). CFE ablation provided only benefit for persistent AF when combined with antral PVI (4 studies, RR 0.55; 95% CI 0.34, 0.87). Conclusions: Despite significant methodological limitations, it appears that additional ablations beyond PVI are necessary for persistent AF but not proven for paroxysmal AF. The optimal technique for persistent AF, however, deserves a further study, in the setting of a large, randomized controlled trial . (J Cardiovasc Electrophysiol, Vol. 22, pp. 729‐738, July 2011)     

Different patterns of atrial remodeling after catheter ablation of chronic atrial fibrillation

Atrial Substrate Remodeling After Chronic AF Ablation . Background: Multiple remodeling patterns have been observed after catheter ablation of atrial fibrillation (AF). Objective: We aimed to clarify the electrical/structural properties associated with recurrences after ablation of chronic AF. Methods: After a stepwise ablation procedure in 120 consecutive patients with persistent/long‐lasting persistent AF, 36 had a recurrence of AF (Group 1/Group 2: recurrence with paroxysmal/persistent AF, n = 16/20). Results: During the first procedure, the left atrial (LA) bipolar voltage did not differ between the 2 groups, and the LA volume was smaller in Group 1 than in Group 2 and it was the only factor predicting the recurrent types (P = 0.009, OR = 1.04). In the second procedure, the bipolar voltage of the global left atrium increased (1.33 ± 0.11 mV vs 1.76 ± 0.16 mV, P = 0.001) in Group 1 and decreased (1.31 ± 0.14 mV vs 0.90 ± 0.12 mV, P = 0.01) in Group 2, when compared with that of the first procedure. The LA low‐voltage area (<0.5 mV) decreased in Group 1, and increased in Group 2. The LA volume (90 ± 8 cm³ vs 72 ± 8 cm³, P = 0.002) decreased in the second procedure in Group 1. It remained the same in Group 2. The right atrial substrates did not change between the procedures. After a follow‐up of 27 ± 3 months, all patients in Group 1 and 14 patients in Group 2 remained in sinus rhythm (P = 0.02). Conclusion: A better outcome with reverse electrical and structural remodeling occurred after the ablation of chronic AF when the recurrence was paroxysmal AF. Progressive electrical remodeling without any structural remodeling developed in those with a recurrence involving persistent AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 385‐393)     

Left Ventricular Diastolic Dysfunction in Atrial Fibrillation: Predictors and Relation with Symptom Severity

Left Ventricular Diastolic Dysfunction in Atrial Fibrillation Background: Left ventricular diastolic dysfunction (LVDD) is common in the general population, but its prevalence in atrial fibrillation (AF), predictors for LVDD in AF and the association between LVDD and AF‐related symptom severity has not been well studied. Methods: In 124 consecutive patients (mean age 61 ± 11years, 60% male) with paroxysmal (n = 70) or persistent AF (n = 54) referred for AF catheter ablation, LVDD was evaluated according to current guidelines using transthoracic echocardiography. AF‐related symptom severity was quantified using the European Heart Rhythm Association score. Results: LVDD was present in 46 patients (37%). In uni‐ and multivariable regression analysis, age (OR 1.068 per year, 95% CI 1.023–1.115, P = 0.003) and persistent AF (OR 2.427 vs. paroxysmal AF, 95% CI 1.112–5.3, P = 0.026) were associated with LVDD. LVDD was found in 11% with mild AF symptoms (n = 27) as opposed to 44% in patients with moderate–severe AF symptoms (n = 97, P = 0.002). Thus, the OR for moderate–severe AF symptoms was 6.368 (1.797–22.568, P = 0.004) in the presence of LVDD. Conclusions: LVDD (1) occurs frequently in AF, (2) is associated with advancing age and AF progression and (3) is correlated with symptom severity in AF. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1073‐1077, October 2012)     

Efficacy of adjuvant anterior left atrial ablation during intracardiac echocardiography-guided pulmonary vein antrum isolation for atrial fibrillation

Background: Recent data have shown that the septum and anterior left atrial (LA) wall may contain “rotor” sites required for AF maintenance. However, whether adding ablation of such sites to standard ICE‐guided PVAI improves outcome is not well known. Objective: To determine if adjuvant anterior LA ablation during PVAI improves the cure rate of paroxysmal and permanent AF. Methods: One hundred AF patients (60 paroxysmal, 40 persistent/permanent) undergoing first‐time PVAI were enrolled over three months to receive adjuvant anterior LA ablation (Group I). These patients were compared with 100 randomly selected, matched first‐time PVAI controls from the preceding three months who did not receive adjuvant ablation (Group II). All 200 patients underwent ICE‐guided PVAI during which all four PV antra and SVC were isolated. In group I, a decapolar lasso catheter was used to map the septum and anterior LA wall during AF (induced or spontaneous) for continuous high‐frequency, fractionated electrograms (CFAE). Sites where CFAE were identified were ablated until the local EGM was eliminated. A complete anterior line of block was not a requisite endpoint. Patients were followed up for 12 months. Recurrence was assessed post‐PVAI by symptoms, clinic visits, and Holter at 3, 6, and 12 months. Patients also wore rhythm transmitters for the first 3 months. Recurrence was any AF/AFL >1 min occurring >2 months post‐PVAI. Results: Patients (age 56 ± 11 years, 37% female, EF 53%± 11%) did not differ in baseline characteristics between group I and II by design. Group I patients had longer procedure time (188 ± 45 min vs 162 ± 37 min) and RF duration (57 ± 12 min vs 44 ± 20 min) than group II (P < 0.05 for both). Overall recurrence occurred in 15/100 (15%) in group I and 20/100 (20%) in group II (P = 0.054). Success rates did not differ for paroxysmal patients between group I and II (87% vs 85%, respectively). However, for persistent/permanent patients, group I had a higher success rate compared with group II (82% vs 72%, P = 0.047). Conclusions: Adjuvant anterior LA ablation does not appear to impact procedural outcome in patients with paroxysmal AF but may offer benefit to patients with persistent/permanent AF.     

Substrate and procedural predictors of outcomes after catheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is often accompanied by atrial fibrillation (AF) due to diastolic dysfunction, elevated left atrial pressure, and enlargement. Although catheter ablation for drug‐refractory AF is an effective treatment, the efficacy in HCM remains to be established. Methods: Thirty‐three consecutive patients (25 male, age 51 ± 11 years) with HCM underwent pulmonary vein (PV) isolation (n = 8) or wide area circumferential ablation with additional linear ablation (n = 25) for drug‐refractory AF. Twelve‐lead and 24‐hour ambulating ECGs, echocardiograms, event monitor strips, and SF 36 quality of life (QOL) surveys were obtained before ablation and for routine follow‐up. Results: Twenty‐one (64%) patients had paroxysmal AF and 12 (36%) had persistent/permanent AF for 6.2 ± 5.2 years. The average ejection fraction was 0.63 ± 0.12. The average left atrial volume index was 70 ± 24 mL/m 2 . Over a follow‐up of 1.5 ± 1.2 years, 1‐year survival with AF elimination was 62%(Confidence Interval [CI]: 66‐84) and with AF control was 75%(CI: 66‐84). AF control was less likely in patients with a persistent/chronic AF, larger left atrial volumes, and more advanced diastolic disease. Additional linear ablation may improve outcomes in patient with severe left atrial enlargement and more advanced diastolic dysfunction. Two patients had a periprocedureal TIA, one PV stenosis, and one died after mitral valve replacement from prosthetic valve thrombosis. QOL scores improved from baseline at 3 and 12 months. Conclusion: Outcomes after AF ablation in patients with HCM are favorable. Diastolic dysfunction, left atrial enlargement, and AF subtype influence outcomes. Future studies of rhythm management approaches in HCM patients are required to clarify the optimal clinical approach.     

Acute Termination of Human Atrial Fibrillation by Identification and Catheter Ablation of Localized Rotors and Sources: First Multicenter Experience of Focal Impulse and Rotor Modulation (FIRM) Ablation

FIRM Ablation of Human AF Rotors. Introduction: Catheter ablation of atrial fibrillation (AF) currently relies on eliminating triggers, and no reliable method exists to map the arrhythmia itself to identify ablation targets. The aim of this multicenter study was to define the use of Focal Impulse and Rotor Modulation (FIRM) for identifying ablation targets. Methods: We prospectively enrolled the first (n = 14, 11 males) consecutive patients undergoing FIRM‐guided ablation for persistent (n = 11) and paroxysmal AF at 5 centers. A 64‐pole basket catheter was used for panoramic right and left atrial mapping during AF. AF electrograms were analyzed using a novel system to identify sustained rotors (spiral waves), or focal beats (centrifugal activation to surrounding atrium). Ablation was performed first at identified sources. The primary endpoints were acute AF termination or organization (>10% cycle length prolongation). Conventional ablation was performed only after FIRM‐guided ablation. Results: Twelve out of 14 cases were mapped. AF sources were demonstrated in all patients (average of 1.9 ± 0.8 per patient). Sources were left atrial in 18 cases, and right atrial in 5 cases, and 21/23 were rotors. FIRM‐guided ablation achieved the acute endpoint in all patients, consisting of AF termination in n = 8 (4.9 ± 3.9 minutes at the primary source), and organization in n = 4. Total FIRM time for all patients was 12.3 ± 8.6 minutes. Conclusions: FIRM‐guided ablation revealed localized AF rotors/focal sources in patients with paroxysmal, persistent and longstanding persistent AF. Brief targeted FIRM‐guided ablation at a priori identified sites terminated or substantially organized AF in all cases prior to any other ablation. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1277‐1285, December 2012)     

Long-Term Implications of Atrial Fibrillation in Patients With Degenerative Mitral Regurgitation

Background

Scientific guidelines consider atrial fibrillation (AF) complicating degenerative mitral regurgitation (DMR) a debated indication for surgery.

Characteristics and significance of very early recurrence of atrial fibrillation after catheter ablation

Very Early Recurrence of AF. Introduction: Early restoration of sinus rhythm following ablation of atrial fibrillation (AF) facilitates reverse atrial remodeling and improves the long‐term outcome. The purpose of this study was to determine the predictors and outcome in patients with very early AF recurrences (< 2 days). Methods and Results: Ablation was performed in 339 consecutive AF patients (paroxysmal AF = 262). Biatrial voltage was mapped during sinus rhythm. If recurrent AF occurred within 2 days following the ablation, electrical cardioversion was performed to restore sinus rhythm. Very early recurrences of AF occurred in 39 (15%) patients with paroxysmal AF and 26 (34%) with nonparoxysmal AF. Patients with very early recurrence had a higher incidence of nonparoxysmal AF (40% vs 18.6%, P< 0.001), requirement of electrical cardioversion during procedure, larger left atrial (LA) diameter (43 ± 7 vs 39 ± 6 mm, P< 0.001), lower left ventricular ejection fraction (54 ± 10% vs 59 ± 7, P< 0.001), longer procedural time, and lower LA voltage (1.5 ± 0.7 vs 1.9 ± 0.8 mV, P< 0.001). A multivariate analysis revealed that the independent predictors of a very early recurrence were a longer procedural time and lower LA voltage. During a follow‐up of 13 ± 5 months, a very early recurrence did not predict the long‐term outcome of a single procedure recurrence in the patients with paroxysmal AF, but was associated with a late recurrence in the nonparoxysmal AF patients. Conclusion: Very early recurrence occurred in patients with paroxysmal AF is not associated with long‐term recurrence. Nonparoxysmal AF is an independent predictor of late recurrence of AF in patients with very early recurrence. (J Cardiovasc Electrophysiol, Vol. pp. 1‐6)     

Image‐Integration of Intraprocedural Rotational Angiography‐Based 3D Reconstructions of Left Atrium and Pulmonary Veins into Electroanatomical Mapping: Accuracy of a Novel Modality in Atrial Fibrillation Ablation

DynaCT Cardiac Integration into Electroanatomical Mapping. Introduction: Exact visualization of complex left atrial (LA) anatomy is crucial for safety and success rates when performing catheter ablation of atrial fibrillation (AF). The aim of our study was to validate the accuracy of integrating rotational angiography‐based 3‐dimensional (3D) reconstructions of LA and pulmonary vein (PV) anatomy into an electroanatomical mapping (EAM) system. Methods and Results: In 38 patients (62 ± 8 years, 25 females) undergoing catheter ablation of paroxysmal (n = 19) or persistent (n = 19) AF, intraprocedural rotational angiography of LA and PVs was performed. The subsequent 3D reconstruction and segmentation of LA and PVs was transferred to the EAM system and registered to the EAM. The distances of all EAM points to corresponding points on the LA syngo® DynaCT Cardiac surface were calculated. Segmentation of LA with clear visualization of adjacent structures was possible in all patients. Also, the integrated segmentation of the LA was used to guide the encirclement of ipsilateral veins, which resulted in PV isolation in all patients. Integration into the 3D mapping system was achieved with a distance error of 2.2 ± 0.4 mm when compared with the EAM surface. Subgroups with paroxysmal and persistent AF showed distance errors of 2.3 ± 0.3 mm and 2.1 ± 0.4 mm, respectively (P = n.s.). Conclusion: Intraprocedural registration of LA and PV anatomy by contrast enhanced rotational angiography was feasible and accurate. There were no differences between patients with paroxysmal or persistent AF. Therefore, integration of rotational angiography‐based reconstructions into 3D EAM systems might be helpful to guide catheter ablation for AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 278–283, March 2010)     

左心房/肺静脉重构在孤立性心房颤动进展中的作用

目的 探讨孤立性心房颤动（房颤）进展过程中左心房/肺静脉重构的作用.方法 连续47例孤立性房颤患者在房颤心律下接受左心房/肺静脉CT检查,其中25例为阵发性房颤,22例为新发持续性房颤.通过对两组间有差异的CT指标进行Logistic回归分析,确定孤立性房颤进展的预测指标.结果 新发持续性房颤组的平均房颤持续时间为1～12（6.4±4.3）周.与阵发性房颤组比较,新发持续性房颤组呈现如下的左心房/肺静脉重构特征：（1）左心房非对称扩张;（2）左心房容积显著增大;（3）肺静脉开口扩张.经Logistic回归分析,左心房容积（P=0.003,OR=1.139,95%可信区间：1.046～1.240）是预测孤立性房颤进展最强的独立指标.左心房容积≥108 ml预测孤立性房颤由阵发性进展为持续性的敏感性为68.2%,特异性为88%.结论 孤立性房颤在由阵发性进展为持续性的过程中伴随有显著的左心房和肺静脉重构;左心房容积显著增加是该过程的独立预测指标.     

High-density mapping of atrial fibrillation in humans: relationship between high-frequency activation and electrogram fractionation

Introduction: Sites of complex fractionated atrial electrograms (CFAE) and dominant frequency (DF) have been implicated in maintaining atrial fibrillation (AF); however, their relationship is poorly understood. Methods and Results: Twenty patients underwent biatrial high‐density contact mapping (507 ± 150 points/patient) during AF. CFAE were characterized using software to quantify electrogram complexity (CFE‐mean). Spectral analysis determined the frequency with greatest power and sites of high DF with a frequency gradient. CFE‐mean was higher (less fractionated) for right compared with left atria (P < 0.001) and in paroxysmal compared with persistent AF (P < 0.001). DF was lower for right compared with left atria (P = 0.02) and in paroxysmal compared with persistent AF (P < 0.001). There was significant regional variation in DF in paroxysmal (P < 0.001) but not persistent AF. Highest DF points clustered together with 5.2 ± 1.7 clusters/patient. Correlation between CFE‐mean and DF was poor on a point‐by‐point basis (r =?0.17, P < 0.001), but moderate on an individual basis (r =?0.50, P = 0.03). Exploration of their spatial relationship demonstrated CFAE areas in close proximity (median 5 mm, IQR 2–10) to high DF sites; within 10 mm in 80% and 10–20 mm in 10%. Simultaneous activation mapping at these sites further supports this observation. Conclusion: Greater fractionation and higher DF are seen in persistent AF and left atria during AF. Preferential areas of high DF are observed in paroxysmal but not persistent AF. CFAE and DF correlate within an individual but not point‐by‐point. Exploration of their spatial relationship demonstrates CFAE in areas adjacent to high DF, and this is supported by activation mapping at these sites.