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)     

Left atrial appendage size is a marker of atrial fibrillation recurrence after radiofrequency catheter ablation in patients with persistent atrial fibrillation

IntroductionThere are no consistently confirmed predictors of atrial fibrillation (AF) recurrence after catheter ablation. Therefore, we aimed to study whether left atrial appendage volume (LAAV) and function influence the long‐term recurrence of AF after catheter ablation, depending on AF type.MethodsAF patients who underwent point‐by‐point radiofrequency catheter ablation after cardiac computed tomography (CT) were included in this analysis. LAAV and LAA orifice area were measured by CT. Uni‐ and multivariable Cox proportional hazard regression models were performed to determine the predictors of AF recurrence.ResultsIn total, 561 AF patients (61.9 ± 10.2 years, 34.9% females) were included in the study. Recurrence of AF was detected in 40.8% of the cases (34.6% in patients with paroxysmal and 53.5% in those with persistent AF) with a median recurrence‐free time of 22.7 (9.3–43.1) months. Patients with persistent AF had significantly higher body surface area‐indexed LAV, LAAV, and LAA orifice area and lower LAA flow velocity, than those with paroxysmal AF. After adjustment left ventricular ejection fraction (LVEF) <50% (HR = 2.17; 95% CI = 1.38–3.43; p < .001) and LAAV (HR = 1.06; 95% CI = 1.01–1.12; p = .029) were independently associated with AF recurrence in persistent AF, while no independent predictors could be identified in paroxysmal AF.ConclusionThe current study demonstrates that beyond left ventricular systolic dysfunction, LAA enlargement is associated with higher rate of AF recurrence after catheter ablation in persistent AF, but not in patients with paroxysmal AF.     

Preprocedural predictors of atrial fibrillation recurrence following pulmonary vein antrum isolation in patients with paroxysmal atrial fibrillation: long-term follow-up results

Predictors of Recurrence after AF Ablation. Introduction: The objective of this study was to identify the simple preprocedural parameters of atrial fibrillation (AF) recurrence following single ablation procedure in patients with paroxysmal AF during long‐term follow‐up period. Methods and Results: Consecutive 474 patients (61 ± 10 years; 364 males, left atrial (LA) diameter 37.6 ± 5.1 mm) with drug‐refractory paroxysmal AF who underwent AF ablation were analyzed. Pulmonary vein antrum isolation (PVAI), cavotricuspid isthmus line creation with bidirectional conduction block, and elimination of all non‐PV triggers of AF were performed in all patients. With a mean follow‐up of 30 ± 13 months after single procedure, 318 patients (67.1%) were in sinus rhythm without any antiarrhythmic drugs. Multivariate analysis using Cox's proportional hazards model, including the age, gender, duration of AF, body mass index, LA size, left ventricular ejection fraction, and presence of hypertension and structural heart disease as variables, demonstrated that LA size was an independent predictor of AF recurrences after PVAI with a 7.2% increase in the probability for every 1 mm increase in LA diameter (P = 0.0007). When the patients were categorized into 3 groups according to the LA diameter, the patients with moderate (40–50 mm) and severe dilatation (>50 mm) had a 1.30‐fold (P = 0.0131) and 2.14‐fold (P = 0.0057) increase, respectively, in the probability of recurrent AF as compared with the patients with normal LA diameter (≤40 mm). Conclusion : In the long‐term follow‐up period, LA size was the best preprocedural predictor of AF recurrence following single ablation procedure in the patients with paroxysmal AF, even in the patients with a relatively small LA. (J Cardiovasc Electrophysiol, Vol. 22, pp. 621‐625, June 2011)     

Long‐Term Results of Transcatheter Atrial Fibrillation Ablation in Patients with Impaired Left Ventricular Systolic Function

AF Ablation and Impaired Left Ventricular Function. Introduction: Long‐term outcome of AF ablation in patients with impaired LVEF is unknown. The aim of this study is to evaluate sinus rhythm (SR) maintenance, clinical status, and echocardiographic parameters over a long‐term period following atrial fibrillation (AF) transcatheter ablation in patients with left ventricular ejection fraction (LVEF) <50%. Methods and Results: A total of 196 patients (87.2% males, age 60.5 ± 10.2 years) with LVEF <50% underwent radiofrequency transcatheter ablation for paroxysmal (22.4%) or persistent (77.6%) AF. Patients were followed up for 46.2 (16.4–63.5) months regarding AF recurrences, functional class, and echocardiographic parameters. All patients underwent pulmonary vein isolation, while 167 (85.2%) required additional atrial lesions. Eleven (5.6%) patients suffered procedural complications. During follow‐up, 58 (29.6%) patients required repeated ablations. At the follow‐up end, 15 (7.7%) patients died, while 74 (37.8%) documented at least one episode of AF, atrial flutter, or atrial ectopic tachycardia. Eighty‐three (47.2%) patients maintained antiarrhythmic drugs. During follow‐up, NYHA class improved by at least one class more frequently among patients maintaining SR compared to those experiencing relapses (70.6% vs 47.9%, P = 0.003). LVEF showed a broader relative increase in patients maintaining SR (32.7% vs 21.4%; P = 0.047) and mitral regurgitation grading significantly decreased (P <0.001) only within these patients. At multivariable analysis SR maintenance emerged as an independent predictor (odds ratio 4.26, 95% CI 1.69–10.74, P = 0.002) of long‐term clinical improvement (reduction in NYHA class ≥1 and relative increase in LVEF ≥10%). Conclusions: Although not substantially worse than in patients with preserved LVEF, AF ablation in patients with impaired LVEF is affected by high long‐term recurrence rate. Among these patients SR maintenance is associated with greater clinical improvement. (J Cardiovasc Electrophysiol, Vol. 24, pp. 24‐32, January 2013)     

Echo Doppler guidance for atrial fibrillation ablation: recognition of primary electropathy

Atrial fibrillation (AF) is a multivariable disease. Young patients with paroxysmal AF without structural cardiac abnormality (“lone AF”) likely have a primary electropathy with excellent results from radiofrequency ablation. However, with persistent AF with cardiac abnormalities, including left atrial enlargement and systolic ventricular dysfunction (ejection fraction percent), the electropathy is considered secondary and ablation results poor. We describe a case with persistent AF, depressed systolic function, and marked left atrial enlargement but without echo Doppler evidence of diastolic dysfunction. At electrophysiology study, findings were consistent with a primary electropathy, and the patient did well following ablation.     

High washout rate of iodine-123-metaiodobenzylguanidine imaging predicts the outcome of catheter ablation of atrial fibrillation

¹²³ I‐MIBG and Ablation for Atrial Fibrillation. Introduction: Excessive sympathetic nervous activity may contribute to atrial fibrillation (AF) recurrences after ablation, but its precise role remains controversial. The goals of this study were to assess the effects of AF on the iodine‐123‐metaiodobenzylguanidine (¹²³I‐MIBG) findings and to elucidate its impact on the procedural outcome in patients undergoing a first‐time catheter ablation to treat AF. Methods and Results: This study included 88 consecutive patients with paroxysmal (n = 48) or persistent (n = 40) AF who underwent radiofrequency catheter ablation and ¹²³I‐MIBG scintigraphy. Five days after the ablation of AF, ¹²³I‐MIBG scintigraphy was performed during sinus rhythm. Anterior planar imaging was obtained at 15 minutes and 180 minutes and the washout rate of the ¹²³I‐MIBG was calculated. The ¹²³I‐MIBG scintigraphy demonstrated an enhanced adrenergic nervous function (high washout rate) and decreased adrenergic nervous distribution (low heart to mediastinum ratios) in patients with both paroxysmal and persistent AF. During a mean follow‐up period of 13.5 ± 2.2 months after the ablation, 25 (28%) patients had AF recurrences. The univariate predictors of an AF recurrence were the duration of the AF history, left atrial dimension, and washout rate of the ¹²³I‐MIBG. Only the ¹²³I‐MIBG washout rate was a multivariate predictor of an AF recurrence (hazard ratio: 1.6, 95% confidence interval: 1.004–1.125, P = 0.037). Conclusions: Excessive sympathetic nervous activation may be one of the mechanisms of AF recurrences. The evaluation of the cardiac nerve activity using ¹²³I‐MIBG scintigraphy shortly after the AF ablation may be a promising tool to predict the patient's outcome. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1297‐1304, December 2011)     

Predictive risk factors for recurrent atrial fibrillation after modified endoscopic ablation: A 2‐year follow‐up

Background

Our previous study reported a modified endoscopic procedure for nonvalvular atrial fibrillation (AF) that requires only 3 ports in the left chest wall.

Hypothesis

Certain preoperative variables might be predictive risk factors for AF recurrence among patients who underwent this procedure.

Methods

From October 2010 to April 2014, 114 patients with either paroxysmal AF (PAF) or nonparoxysmal AF (non‐PAF) underwent the procedure and completed postoperative cardiac‐rhythm measurement via electrocardiography and Holter monitoring. Univariate and multivariate analyses of the possible AF‐related risk factors were conducted.

Results

During 2‐year follow‐up, 99 of 114 patients (86.8%) were free from atrial tachyarrhythmia. Results from univariate analyses showed that AF duration, left atrial diameter (LAD), left atrial minimum volume, left atrial empty fraction, left atrial expansion index, and left atrial active empty fraction (LAAEF) were significantly associated with postoperative AF recurrence. Results from multivariate analyses showed that AF duration (odds ratio [OR]: 1.194, 95% CI: 1.063‐1.340, P = 0.003), LAD (OR: 1.101, 95% CI: 1.005‐1.205, P = 0.039), and LAAEF (OR: 0.490, 95% CI: 0.277‐0.865, P = 0.014) were independent risk factors. There was no difference in AF recurrence between patients with PAF and non‐PAF (P = 0.250).

Conclusions

Our 2‐year follow‐up study suggested that low LAAEF, long AF duration, and large LAD might be potential predictive risk factors for AF recurrence. Patients with PAF and non‐PAF had a similar AF recurrence rate after modified endoscopic ablation.     

Baseline B-type natriuretic peptide: a gender-specific predictor of procedure-outcome in atrial fibrillation patients undergoing catheter ablation

Baseline BNP Predicts Ablation Outcome in Male AF Patients. Background: Close association between atrial fibrillation (AF) and brain natriuretic peptide (BNP) has been demonstrated by several studies. Important gender differences exist in AF patients including a higher plasma BNP level in women. Therefore, it is imperative to evaluate the relationship between AF and BNP separately in men and women. Objective: This study examined possible gender‐specific role of BNP in predicting procedure outcome in AF patients undergoing catheter ablation. Method: The study population included 568 consecutive patients (age 62 ± 10, male 73%, paroxysmal 25%, persistent 38%, and long‐standing persistent AF 37%) undergoing AF ablation, who had structurally normal heart and left ventricular ejection fraction ≥45%. Baseline BNP was measured in all. Patients were grouped into “normal” and “high” BNP based on gender‐specific cut‐off values (<50 and ≥50 pg/mL in males, <100 and ≥ 100 pg/mL in females). Result: Baseline BNP was significantly higher among women than men (126 ± 112 versus 87 ± 99, P = 0.009). At 12 ± 6 month follow‐up, 304 of 414 (73%) males and 98 of 154 (64%) females were AF/atrial tachycardia‐free off antiarrhythmic drugs (log‐rank P = 0.018). In multivariable analysis, BNP remained an independent predictor of AF recurrence (BNP ≥ 50: hazard ratio [HR] 2.54, P = 0.006) in males. No such association was observed among females (BNP ≥ 100: HR 0.79, 95% CI 0.43–1.42; P = 0.426). Conclusion: Baseline BNP was found to be an independent predictor of AF recurrence in male patients undergoing ablation. This correlation between BNP and AF recurrence was not observed in females. Thus, BNP plays a gender‐specific prognostic role in AF . (J Cardiovasc Electrophysiol, Vol. 22, pp. 858‐865, August 2011)     

心房颤动射频消融术后晚期复发的相关因素

目的:分析心房颤动（房颤）经导管射频消融术后晚期复发的相关因素。方法:房颤患者117例接受经导管射频消融术治疗,术前进行常规检查评估,在CARTO三维标测系统指导下行左房环肺静脉消融,必要时加行左房线性消融、右房线性消融等策略。如果在消融结束后心电监护仍为房颤心律,则行体外电复律。通过术后随访（>3个月）确定房颤消融术后是否复发,收集相关的随访资料分析房颤术后晚期复发的预测因素。结果:①所有患者均完成环肺静脉隔离。58例患者在环肺静脉消融基础上加行左房线性消融、右房线性消融等方法。37例房颤患者在消融后房颤仍持续,经体外电转复均恢复窦律。32例(27.3%)患者在术后晚期复发。②单因素分析显示性别、并发器质性心脏病、房颤病程、持续性房颤、左房内径、左室射血分数和复律与术后房颤晚期复发相关（均P<0.05）。③经多因素分析后仅有性别、左房内径、房颤病程是房颤晚期复发的独立预测指标(分别P<0.05,P<0.05,P<0.01)。结论:性别、房颤病程、左房内径是房颤导管消融术后晚期复发的独立预测因素。     

Atrioventricular Nodal Reentrant Tachycardia with Paroxysmal Atrial Fibrillation: Clinical and Electrophysiological Features and Predictors of Atrial Fibrillation Recurrence Following Elimination of Atrioventricular Nodal Reentrant Tachycardia

Introduction: Clinical and electrophysiological characteristics of patients with atrioventricular nodal reentrant tachycardia (AVNRT) and paroxysmal atrial fibrillation (AF) have not been studied in a large patient cohort. We aimed to define the clinical features and cardiac electrophysiological characteristics of these patients, and to examine the incidence and identify predictors of AF recurrences after elimination of AVNRT. Methods and Results: Thirty-six patients with AVNRT and documented paroxysmal AF (Group 1) and 497 patients with AVNRT alone undergoing ablation in the same period (Group 2) were studied. There were no significant differences between groups regarding clinical features, except age, which was higher in Group 1 (p < 0.001). Presence of atrial vulnerability (induction of AF lasting > 30 seconds) and multiple AH jumps (≥50 ms) before ablation were significantly more prevalent in Group 1 (p < 0.001, p = 0.010 respectively). During follow-up of 34 ± 11 months, AF recurred in 10 patients (28%) in Group 1, while 2 patients in Group 2 (0.4%) developed paroxysmal AF (p < 0.001). Univariate predictors of AF were: left atrial diameter > 40 mm (p = 0.001), presence of mitral or aortic calcification (p = 0.003), atrial vulnerability after ablation (p = 0.015) and valvular disease (p = 0.042). However, independent predictors of AF recurrences were left atrial diameter > 40 mm (p = 0.002) and the presence of atrial vulnerability after ablation (p = 0.034). Conclusion: In patients with both AVNRT and paroxysmal AF, the recurrence rate of AF after elimination of AVNRT is 28%. Left atrial diameter greater than 40 mm and atrial vulnerability after elimination of AVNRT are independent predictors of AF recurrences in the long term.     

Effect of radiofrequency ablation of atrial flutter on the natural history of subsequent atrial arrhythmias

Introduction: Patients with atrial flutter (AFL) treated medically are at high risk for subsequent development of atrial fibrillation (AF). Whether curative radiofrequency ablation of AFL can modify the natural history of arrhythmia progression is not clear. We aimed to determine whether ablation of AFL decreases the subsequent development of AF in patients without previous AF. Methods and Results: Patients with AFL as the sole atrial arrhythmia were selected from patients who underwent successful AFL ablation at Mayo Clinic between 1997 and 2003 (N = 137). The cohort was divided by presence (n = 50) or absence (n = 87) of structural heart disease. A control group comprised 59 patients with AFL and no history of paroxysmal AF, who received only medical therapy. Occurrence of AF after AFL ablation was compared among study groups and controls. Symptomatic AF occurred in 49 patients during 5 years of follow‐up after AFL ablation, with similar frequency in both study groups. The cumulative probability of paroxysmal and chronic AF was similar in controls and each study group. By multivariate analysis, the AFL ablation procedure carries significant risk of AF occurrence during follow‐up. Fifty patients discontinued antiarrhythmic drugs after AFL ablation, and the rate of cardioversions decreased. Conclusion: Successful ablation of AFL does not improve the natural history of atrial arrhythmia progression; postablation AF is frequent. This suggests that AFL may be initiated by bursts of AF and that in the absence of AFL substrate the AF continues to progress.     

Long‐Term Outcome of Atrial Fibrillation Ablation: Impact and Predictors of Very Late Recurrence

Long‐Term Outcome of AF Ablation. Introduction: Ablation eliminates atrial fibrillation (AF) in studies with 1 year follow‐up, but very late recurrences may compromise long‐term efficacy. In a large cohort, we sought to describe the determinants of delayed recurrence after AF ablation. Methods and Results: Seven hundred and seventy‐four patients with AF (428 paroxysmal [PAF, 55%] and 346 persistent or longstanding persistent [PersAF, 45%]) underwent wide area circumferential ablation (WACA, 62%) or pulmonary vein isolation (38%). Over 3.0 ± 1.9 years, there were 135 recurrences in PAF patients and 142 in PersAF patients. AF elimination was achieved in 61% of patients with PersAF at 2 years after last ablation and in 71% of patients with PAF (P = 0.04). This finding was related to a higher initial rate of very late recurrence in PersAF. From 1.0 to 2.5 years, the recurrence increased by 20% (from 37% to 57%) in PersAF patients versus only 12% (from 27% to 39%) in PAF patients. Independent predictors of overall recurrence included diabetes (HR 1.9 [1.3–2.9], P = 0.002) and PersAF (HR 1.6 [1.2–2.0], P < 0.001). Independent predictors of very late recurrence included PersAF (HR 1.7 [1.1–2.7], P = 0.018) and WACA (HR 1.8 [1.1–2.7], P = 0.018), while diabetes came close to significance. In PAF patients, left atrial size >45 mm was identified as an AF‐type specific predictor (HR 2.4 [1.3–4.7], P = 0.009), whereas in PersAF patients, no unique predictors were identified. Conclusion: Late recurrences reduced the long‐term efficacy of AF ablation, particularly in patients with PersAF and underlying cardiovascular diseases. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1071‐1078)     

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.     

Impact of adenosine-provoked acute dormant pulmonary vein conduction on recurrence of atrial fibrillation

Impact of ATP Reconduction on AF Recurrence. Introduction: Adenosine can be associated with acute recovery of conduction to the pulmonary veins (PVs) immediately after isolation. The objective of this study was to evaluate whether the response to adenosine predicts atrial fibrillation (AF) recurrence after a single ablation procedure in patients with paroxysmal AF. Methods and Results: A total of 109 consecutive patients (61 ± 10 years; 91 males) with drug‐refractory paroxysmal AF who underwent AF ablation were analyzed. After PV antrum isolation (PVAI), dormant PV conduction was evaluated by an administration of adenosine in all patients. No acute reconnections were provoked by the adenosine in 70 (64.2%) patients (Group‐1), but they were provoked in at least one side of the ipsilateral PVs in 39 (35.8%) patients (Group‐2). All adenosine‐provoked dormant conductions were successfully eliminated by additional ablation applications. By 12 months after the initial procedure, 72 (66.1%) patients were free of AF recurrences without any antiarrhythmic drugs. A Cox regression multivariate analysis of the variables including the adenosine‐provoked reconductions, age, gender, duration of AF, presence of hypertension or structural heart disease, left atrial size, left ventricular ejection fraction, and body mass index demonstrated that adenosine‐provoked reconductions were an independent predictor of AF recurrence after a single ablation procedure (hazard ratio: 1.387; 95% confidence interval: 1.018–1.889, P = 0.038). At the repeat session for recurrent AF, conduction recovery was observed similarly in both groups (P = 0.27). Conclusion: Even after the elimination of any adenosine‐provoked dormant PV conduction, the appearance of acute adenosine‐provoked reconduction after the PVAI was an independent predictor of AF recurrence after a single AF ablation procedure. (J Cardiovasc Electrophysiol, Vol. 23 p. 256‐260, March 2012.)     

房颤射频消融术术后AF早期复发的预测因素

房颤(AF)是临床上最常见的一种心律失常。AF射频消融术作为一种非药物治疗AF的手段正被广泛利用,但术后AF的复发率较高。早期有研究显示,高龄、超重和肥胖、病程、左房内径、左房疤痕和纤维化等为预测AF消融术术后AF复发的相关因素。最新研究显示,阻塞性睡眠呼吸暂停综合征、伴有慢性肾脏疾病、4q25等位基因多态性等对AF早期复发的预测具有一定的意义。     

Is Pursuit of Termination of Atrial Fibrillation During Catheter Ablation of Great Value in Patients with Longstanding Persistent Atrial Fibrillation?

Termination of Atrial Fibrillation During Catheter Ablation Predicts Better Outcome . Background: The reliable endpoint for ablation of longstanding persistent atrial fibrillation (LPAF) has not been clearly established. Methods and Results: This study included 140 patients who underwent catheter ablation for drug‐refractory LPAF. A stepwise ablation approach included circumferential pulmonary vein isolation followed by left atrial and right atrial complex fractionated electrogram‐guided ablation. Atrial fibrillation (AF) was terminated by radiofrequency application during catheter ablation in 95 patients (67.9%). Among them, 33 patients (23.6%) converted to sinus rhythm directly, whereas 62 patients (44.3%) via atrial tachycardias (ATs). Patients in whom AF terminated during the index procedure had a lower recurrence rate of atrial arrhythmia than patients in whom AF did not terminate (45.3% vs 68.9%, P = 0.009, follow‐up 18.7 ± 7.6 months). Among patients in whom AF terminated, there was no significant difference in recurrence rate according to the termination mode, whether converted to AT or not (P = NS). However, patients who converted to AT had a higher recurrence rate of AT (54.8% vs 81%; P = 0.016). Multivariable logistic regression analysis demonstrated that termination of AF during ablation (HR 0.440; 95% CI: 0.200–0.969, P = 0.041) and structural heart disease (HR 2.633; 95% CI: 1.211–5.723; P = 0.015) were significant independent factors predicting the recurrence of atrial arrhythmia. Conclusions: Termination of AF during catheter ablation is associated with a better clinical outcome in patients with LPAF. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1051‐1058, October 2012)     

The Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation (MAGIC-AF) Study: clinical background and study design

The MAGIC‐AF Study. Background: Beyond pulmonary vein isolation (PVI), adjuvant ablation at the sites of complex fractionated atrial electrograms (CFAE) has been shown to improve the long‐term success of catheter ablation of persistent atrial fibrillation (AF). However, this approach often requires extensive ablation due to the widespread distribution of CFAE within the left atrium. An optimal strategy would identify areas of CFAE which, when selectively targeted with ablation, result in AF termination with an acceptable long‐term freedom from AF. It is possible that the intraprocedural administration of an antiarrhythmic drug may help accomplish this. Objective: The Modified Ablation Guided by Ibutilide Use in Chronic AF (MAGIC‐AF) Study is an international multicenter prospective randomized double‐blinded clinical trial assessing the utility of the intraprocedural administration of 0.25 mg of intravenous ibutilide before performing CFAE ablation. The primary efficacy endpoint of this study will be the freedom from AF at 1 year after a single procedure off antiarrhythmic agents. Safety endpoints will include procedural and radiofrequency ablation time as well as overall procedural complication rate. Methods: Patients undergoing a first ever catheter ablation procedure for persistent AF will be included. Individuals with hypertrophic cardiomyopathy, complex congenital heart disease including atrial septal defects, and ejection fraction <35% will be excluded from the study. All patients will first undergo PVI. Those patients who remain in AF will then be randomized in a 1:1 fashion to receive either 0.25 mg intravenous ibutilide or saline placebo followed by a CFAE based ablation strategy. Two hundred randomized patients will be enrolled in this study—100 in each study arm. Conclusion: The MAGIC‐AF study will assess the utility of a combined pharmaco‐ablative strategy in patients with persistent AF undergoing a CFAE based ablation strategy.     

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.     

P Wave Dispersion Predicts Recurrence of Paroxysmal Atrial Fibrillation in Patients with Atrioventricular Nodal Reentrant Tachycardia Treated with Radiofrequency Catheter Ablation

Background: Paroxysmal atrial fibrillation (AF) recurs in up to one‐third of patients with atrioventricular nodal reentrant tachycardia (AVNRT) treated with slow pathway ablation. Therefore, identification of patients at risk for recurrence of AF after slow pathway ablation is important because of the necessity for additional therapies. The purpose of this study was to determine whether successful slow pathway ablation influences P wave parameters and whether these parameters predict the recurrence of paroxysmal AF in patients with both AVNRT and paroxysmal AF after ablation. Methods: Thirty‐six patients with AVNRT and documented paroxysmal AF (Group 1) were compared to 36 age‐matched controls with AVNRT only (Group 2). P wave durations and P dispersion were measured before and after ablation. Results: No significant differences were observed between P wave parameters observed before and after ablation. Maximum P wave durations (Pmax) and P dispersion (Pdisp) were significantly higher in Group 1 than in Group 2 (P < 0.001 for both) whereas minimum P wave durations did not differ between groups, both before and after ablation. Ten patients (28%) in Group‐1 had recurrence of AF during a mean follow‐up of 34 ± 11 months. Univariate predictors of AF recurrence were Pdisp ≥35.5 ms (P < 0.010), left atrial diameter >40 mm (P < 0.010), mitral or aortic calcification (P < 0.010), Pmax ≥112 ms (P < 0.050), valvular heart disease (P < 0.050), and atrial vulnerability (induction of AF lasting >30 second) after ablation (P < 0.050). However, only Pdisp ≥35.5 ms (P < 0.050) and left atrial diameter >40 mm (P < 0.010) were independent predictors of AF recurrences. Conclusion: This study suggests that P wave dispersion could identify patients with AVNRT susceptible to recurrence of AF after slow pathway ablation.     

Clinical Significance of Early Recurrences of Atrial Tachycardia After Atrial Fibrillation Ablation

Early Recurrence After AF Ablation. Background: Atrial tachycardia (AT) commonly recurs within 3 months after radiofrequency catheter ablation for atrial fibrillation (AF). However, it remains unclear whether early recurrence of atrial tachycardia (ERAT) predicts late recurrence of AF or AT. Methods: Of 352 consecutive patients who underwent circumferential pulmonary vein isolation with or without linear ablation(s) for AF, 56 patients (15.9%) with ERAT were identified by retrospective analysis. ERAT was defined as early relapse of AT within a 3‐month blanking period after ablation. Results: During 21.7 ± 12.5 months, the rate of late recurrence was higher in patients with ERAT (41.1%) compared with those without ERAT (11.8%, P < 0.001). In a multivariable model, positive inducibility of AF or AT immediately after ablation (65.2% vs 36.4%, P = 0.046; odd ratio, 3.9; 95% confidence interval, 1.0–14.6) and the number of patients who underwent cavotricuspid isthmus (CTI) ablation (73.9% vs 42.4%, P = 0.042; odd ratio, 4.5; 95% confidence interval, 1.1–19.5) were significantly related to late recurrence in the ERAT group. The duration of ablation (174.3 ± 62.3 vs 114.7 ± 39.5 minutes, P = 0.046) and the procedure time (329.3 ± 83.4 vs 279.2 ± 79.7 minutes, P = 0.027) were significantly longer in patients with late recurrence than in those without late recurrence following ERAT. Conclusions: The late recurrence rate is higher in the patients with ERAT compared with those without ERAT following AF ablation, and is more often noted in the patients who underwent CTI ablation and had a prolonged procedure time. Furthermore, inducibility of AF or AT immediately after ablation independently predicts late recurrence in patients with ERAT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1331‐1337, December 2010)