Increase in Cerebral Blood Flow After Catheter Ablation of Atrial Fibrillation.

BACKGROUND: Recent studies have found that atrial fibrillation (AF) is a risk factor for cognitive impairment. Brain hypoperfusion is hypothesized as an underlying mechanism of cognitive decline in AF patients. OBJECTIVES: This study sought to assess changes in cerebral blood flow (CBF) and brain volume after catheter ablation of AF. METHODS: Patients undergoing catheter ablation of AF were enrolled in this prospective study. AF patients being treated with pharmaceuticals alone served as a control group. Brain magnetic resonance imaging was performed before and 6 months after catheter ablation. CBF was assessed by 2-dimensional phase-contrast magnetic resonance angiography. Brain volume and bilateral hippocampal volume were measured using FreeSurfer software. RESULTS: Of the 57 study patients (age 64 ± 11 years; 45 men; paroxysmal AF: n = 22; nonparoxysmal AF: n = 35), 48 patients were freed from tachyarrhythmia recurrence beyond a 3-month blanking period. Changes in CBF and brain perfusion over 6 months were significantly greater in the study patients than control (CBF: 39.26 vs -34.86 mL; P = 0.01, ANCOVA; brain perfusion: 3.78 vs -3.02 mL/100 mL/min; P = 0.009, ANCOVA), while changes in total brain volume and bilateral hippocampal volume were similar between 2 groups (total brain volume: 2.57 vs -2.15 mL; P = 0.32, ANCOVA; bilateral hippocampal volume: 0.03 vs 0.04 mL; P = 0.8, ANCOVA). Nonparoxysmal AF at baseline was an independent predictor of an increase in CBF of >32.6 mL/min. CONCLUSIONS: Catheter ablation of AF has favorable effects on CBF, particularly in nonparoxysmal AF. Our results may partially explain the association between cognitive decline and AF.

The impact of left atrium size on selection of the pulmonary vein isolation method for atrial fibrillation: Cryoballoon or radiofrequency catheter ablation.

BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of ablation strategies for atrial fibrillation (AF), and noninferiority of cryoballoon (CB) over radiofrequency (RF) ablation has been previously reported. One of the risk factors of recurrence is left atrium (LA) enlargement. This study aimed to analyze the impact of LA enlargement on the selection of CB or RF ablation for AF patients. METHODS: A total of 2,224 AF patients (64.4 ±â€¯10.7 years, 65.5% male) who underwent PVI were analyzed retrospectively. Left atrial diameter (LAD) and volume (LAV) were measured using echocardiography before the procedures. LA enlargement was defined as LAD ≥40 mm and LAV index (LAVI) ≥35 mL/m2. Patients undergoing CB and RF ablation were propensity score matched, and 376 matched pairs were evaluated. RESULTS: Cox proportional hazard analysis revealed that LAD (95% CI, 1.01-1.05), LAV (95% CI, 1.01-1.02), and LAVI (95% CI, 1.01-1.03) were independent predictors of recurrence. CB showed equivalent clinical outcomes to those of RF with shorter procedure time required for patients without LA enlargement. CB was inferior to RF in patients with LA enlargement (LAD, 74.5% vs 84.6%, P = .028; LAVI, 74.7% vs 83.4%, P = .015), and large LAVI was associated with a higher prevalence of non-PV foci (35% vs 29%, P = .008). CONCLUSIONS: CB ablation may be recommended for patients without enlarged LA based on the short procedure time and efficacy, whereas RF would be more appropriate in large LAs. LAVI may be a valuable reference to predict PVI outcomes and in selecting the ablation method.

Association between the locations of non-pulmonary vein triggers and ablation outcomes in repeat procedures after cryoballoon ablation of paroxysmal atrial fibrillation.

PURPOSE: We examined the characteristics of non-pulmonary vein (PV) triggers in repeat ablation after cryoballoon ablation for paroxysmal atrial fibrillation (PAF). METHODS: This study evaluated 119 patients undergoing a second ablation procedure for recurrent atrial tachyarrhythmia (ATA) after cryoballoon PV isolation (CB-PVI) for PAF. RESULTS: Fifty-three of 119 (45%) patients had PV reconnection. All reconnected PVs were isolated. No non-PV triggers were elicited in 42/119 (35%) patients (NNPV group). In 77/119 (65%) patients, 139 isoproterenol-induced non-PV triggers, including 45 triggers that initiated AF, were identified. Non-PV triggers initiating AF were observed at the superior vena cava (SVC), left atrial posterior wall (LAPW) including the PV antra, interatrial septum, right atrium, left atrial appendage/mitral anulus, and coronary sinus in 14 (12%), 10 (8%), 8 (7%), 7 (6%), 4 (3%), and 2 (2%) patients, respectively. Non-PV triggers originated from only the SVC and/or LAPW including the PV antra, and the SVC and/or LAPW was isolated in 18/119 (15%) patients (SVC/LAPW group). Non-PV triggers originating from other sites were focally ablated in 59/119 (50%) patients (OS group). During a median 461 days of follow-up, 39/42 (93%), 17/18 (94%), and 38/59 (64%) patients in the NNPV, SVC/LAPW, and OS groups, respectively, remained ATA recurrence-free. The recurrence rate was higher in the OS group than in the NNPV (P = 0.005) or SVC/LAPW groups (P = 0.042). CONCLUSIONS: Over half of patients had non-PV triggers at subsequent ablation after CB-PVI. Non-PV triggers from the SVC/LAPW can be eliminated more successfully than triggers from other sites.

A Survey of Direct Oral Anticoagulant Cessation in General Surgery and Outcomes in Patients with Nonvalvular Atrial Fibrillation.

There is little data on management and outcomes of atrial fibrillation (AF) patients on direct oral anticoagulants (DOAC) undergoing general surgery.We retrospectively assessed 98 surgeries in 85 nonvalvular AF patients aged 73 ± 8 (59 men) receiving DOACs. Cardiac, emergency, and minimally invasive surgeries were excluded.The CHA2DS2-VASc score ranged from 0 to 8. The DOACs being given were: dabigatran, 16; rivaroxaban, 25; apixaban, 28; and edoxaban, 16. While the DOACs were not suspended in 11 cases, they were interrupted for a median of 2.0 days before surgery and restarted at a median of 3.0 days after surgery. There were 9 complications (9.2%), 3 instances of thromboembolism and 6 bleeding. Thromboembolism occurred at a mean of 3.0 postoperative days, all of which occurred before resumption of DOACs, while bleeding events occurred at a mean of 4.0 postoperative days. Two of the 3 patients with thromboembolism went into cardiopulmonary arrest during the event, but were resuscitated. There were significantly more patients with congestive heart failure or combined antiplatelets in the patients with complications. The complication group had a significantly higher HAS-BLED score and lower preoperative hemoglobin level. There were no significant differences in the management of DOAC interruption between those with complications and without.The perioperative complication rate in nonvalvular AF patients undergoing elective surgery treating with DOACs was 9.2%. Patients with congestive heart failure, receiving combined therapy with antiplatelets, a higher HAS-BLED score, or lower preoperative hemoglobin level were at higher risk. Further studies evaluating the ideal perioperative DOAC protocol are warranted.

Cryoballoon versus radiofrequency ablation for paroxysmal atrial fibrillation in hemodialysis patients.

INTRODUCTION: Little evidence exists regarding cryoballoon ablation (CBA) of paroxysmal atrial fibrillation (PAF) in hemodialysis (HD) patients. We compared CBA and radiofrequency ablation (RFA) of PAF in HD patients, referring to CBA of PAF in non-HD patients. METHODS AND RESULTS: This historical cohort study examined 88 patients who underwent catheter ablation of PAF, including 21 HD patients with a second-generation 28-mm cryoballoon (CB-HD group), 17 HD patients with a non-force-sensing radiofrequency catheter (RF-HD group), and 50 non-HD patients with a cryoballoon (CB-non-HD group). Pulmonary vein (PV) isolation alone aside from cavotricuspid isthmus ablation was performed in 14 (67%) in the CB-HD group, 12 (71%) in the RF-HD group, and 36 (72%) in the CB-non-HD group (P = 0.95), without isoproterenol-induced non-PV triggers. Non-PV trigger ablation was added to the other patients. The Kaplan-Meier estimated 1-year freedom from atrial tachyarrhythmia recurrence without antiarrhythmic drugs after a single procedure was 76%, 59%, and, 92% in the CB-HD, RF-HD, and CB-non-HD groups, respectively (P = 0.002). The mean procedure time was shorter in the CB-HD group than in the RF-HD group (127 vs. 199 min; P < 0.001). In the second procedure, the median number of reconnected pulmonary veins was 0.5 in the CB-HD group versus 2.0 in the RF-HD group (P = 0.17). CONCLUSION: For PAF in HD patients, CBA showed a comparable single-procedure efficacy to that of RFA with a short procedure time. CBA may be a reasonable initial procedure for HD patients suffering from symptomatic PAF.

Pulmonary vein narrowing after visually guided laser balloon ablation: Occurrence and clinical correlates.

INTRODUCTION: There are limited data focusing on pulmonary vein (PV) narrowing following ablation using a visually guided laser balloon (VGLB). We sought to assess the frequency and predictors of PV narrowing after VGLB ablation. METHODS AND RESULTS: Patients with paroxysmal atrial fibrillation treated with VGLB were screened. Study participants underwent contrast-enhanced computed tomography (CT) scanning before and 6 months after the procedure. We defined 25% to 49%, 50% to 74%, and 75% to 100% reduction in PV cross-sectional area as mild, moderate, and severe narrowing, respectively. Of 146 PVs in 38 patients analyzed, severe narrowing developed in two right superior and one right inferior PV. Moderate or severe narrowing occurred in 40 veins (27% of all PVs, 50% of the right superior, 22% of the right inferior, 21% of the left superior, and 14% of the left inferior PV). In PVs with moderate-severe narrowing, the baseline orifice area was significantly larger (4.1 [interquartile range, 3.2-4.8] vs 2.5 [1.9-3.3] cm2 , P < .0001), the narrowest region of stenosis was significantly more distal into the vessel (1.9 [0.7-2.9] vs 0 [0-1.7] mm from the orifice, P = .0006) and the total amount of energy delivered per vein was significantly greater (5190 ± 970 vs 4626 ± 1573 J, P = .018) than in PVs with mild or no significant narrowing. The baseline orifice area independently predicted moderate-severe narrowing in multivariate analysis (odds ratio, 1.8 [1.3-2.5] per 1 cm2 increase, P = .0003). No patient exhibited any signs or symptoms of PV stenosis. CONCLUSIONS: Baseline PV orifice area, ablating distally inside the veins, and total amount of laser energy are associated with PV narrowing after VGLB ablation.

Characteristics of the nonpulmonary vein foci induced after second-generation cryoballoon ablation for paroxysmal atrial fibrillation.

INTRODUCTION: Pulmonary vein isolation (PVI) using cryoballoon is effective for patients with paroxysmal atrial fibrillation (PAF); however, few reports have evaluated the non-pulmonary vein (PV) foci after cryoballoon ablation. We aimed to evaluate the characteristics of non-PV foci and predictors of atrial fibrillation (AF) recurrence after cryoballoon ablation. METHODS AND RESULTS: This was a single-center retrospective study of 647 patients with PAF who underwent initial PVI using a second-generation cryoballoon. After PVI, all patients underwent high-dose isoproterenol infusion to assess the existence of non-PV foci. Non-PV foci were observed in 211 patients (32.6%), which were most frequently observed in the superior vena cava. Higher age (odds ratio [OR] = 1.02; 95% confidence interval [CI] = 1.00-1.04; P = .025), female sex (OR = 1.65; 95% CI = 1.13-2.41; P = .009), and lower body mass index (OR = 0.95; 95% CI = 0.89-1.00; P = .049) were significantly associated with non-PV foci. The existence of non-PV foci was an independent predictor of AF recurrence (Hazard's ratio = 1.70; 95% CI = 1.12-2.60; P = .014). When non-PV foci were mappable and successfully ablated, patients with non-PV foci showed similar outcomes with those without non-PV foci (1-year AF-free survival rates of 88.5% vs 91.5%; P = .338). Conversely, when we failed to detect and eliminate non-PV foci because they had multiple origins and were not consistently inducible (multichanging non-PV foci), the 1-year AF-free survival rate was 56.4% even after substrate modification. CONCLUSION: Non-PV foci were observed in one-third of patients with PAF after cryoballoon ablation and were associated with AF recurrence. Catheter ablation for non-PV foci was effective when they were mappable; however, multichanging non-PV foci were associated with worse prognosis.

Differences in the electrophysiological findings of repeat ablation between patients who first underwent cryoballoon ablation and radiofrequency catheter ablation for paroxysmal atrial fibrillation.

INTRODUCTION: Several studies have revealed that second-generation cryoballoon (CB)-based pulmonary vein (PV) isolation is noninferior to radiofrequency (RF)-based PV isolation for patients with drug-refractory paroxysmal atrial fibrillation (AF). However, electrophysiological differences in repeat ablation remain unclear. METHODS AND RESULTS: This study examined electrophysiological differences during the repeat ablation between patients who first underwent RF catheter ablation and CB ablation; PV durability and non-PV AF foci were assessed for these patients. We enrolled 919 and 491 patients who underwent CB ablation (CB group) and RF catheter ablation (RF group), respectively, for paroxysmal AF between January 2013 and June 2017 at our institution. PV isolation using RF ablation involved the left atrium (LA) antrum and part of the LA posterior wall. After 2 years of follow-up, 62 and 80 patients in the CB and RF groups, respectively, underwent repeat ablation. PV reconnections were more frequent in the RF group than in the CB group (left superior PV: 46.2% and 14.5%, P < .001; left inferior PV: 35.0% and 11.2%, P = .001; right superior PV: 40.0% and 22.6%, P = .031; right inferior PV: 36.2% and 19.4%, P = .039; PVs: 39.8% and 16.9%, P < .001). LA AF foci were more frequent in the CB group than in the RF group (27.4% and 7.5%; P = .002). Other non-PV foci were prevalent in both groups. CONCLUSION: Fewer LA-PV reconnections occurred with CB ablation. However, extensive PV isolation may eliminate many LA AF foci.

Propensity-matched comparison of cryoballoon and radiofrequency ablation for atrial fibrillation in elderly patients.

BACKGROUND: Pulmonary vein isolation (PVI) with a cryoballoon (CB) is an effective treatment for atrial fibrillation (AF). The efficacy of CB PVI for elderly patients with AF remains unclear. OBJECTIVE: We aimed to analyze the clinical outcomes of CB ablation compared with radiofrequency (RF) ablation in elderly patients with AF. METHODS: This was a single-center retrospective study of 305 patients older than 75 years with paroxysmal and persistent AF who underwent PVI between January 2012 and August 2017. Patients were matched according to propensity scores in a logistic regression model. The end point of this study was AF/atrial tachycardia recurrence at 12-month follow-up. RESULTS: In total, 198 patients (99 matched pairs) were analyzed. The ratio of paroxysmal AF was 83%, and the mean age was 78 ± 2 years. The mean procedure time was significantly lower in the CB group (134 ± 62 minutes vs 190 ± 51 minutes; P < .001). There was no significant difference between the groups in terms of success rate at 12 months after the procedure (CB 80.5% vs RF 79.4%; P = .72) or incidence of complications (CB 12% vs RF 16%; P = .80). Kaplan-Meier estimates revealed no significant difference between clinical outcomes after PVI with a CB or RF for elderly patients with non-pulmonary vein foci that were all successfully ablated (CB 68.8% vs RF 68.4% at 12 months; P = .835). CONCLUSION: The efficacy of PVI with a CB might be comparable to that of PVI with RF in AF patients older than 75 years and involve a shorter procedure time.

Candidacy for a Subcutaneous Implantable Cardioverter Defibrillator in Patients with Cardiac Resynchronization Therapy.

In patients requiring an implantable cardioverter defibrillator (ICD), the combined use of a prior pacemaker and a subcutaneous ICD (S-ICD) could be an alternative treatment option to implantation of new leads or upgrading of pacemakers to an ICD if vascular access is limited. Here, we assessed the prevalence of S-ICD's eligibility according to surface electrogram screening in those receiving cardiac resynchronization therapy (CRT). S-ICD's eligibility was assessed in patients with a CRT pacemaker or a CRT defibrillator using the S-ICD template screening tool. Eligibility was defined as fulfillment of the template in both supine and upright positions in one or more leads during biventricular pacing. Among 44 patients (34 men, age: 67 ± 12), 36 (82%) were found to be eligible. The T/QRS amplitude ratio in lead II was significantly lower in those who were eligible (0.31 ± 0.16 versus 0.44 ± 0.18 in the ineligible group, P = 0.04). The lead position, underlying disease, and other electrocardiographic findings were not different between those who were eligible and those who were not. The majority of patients with biventricular pacing were eligible for S-ICD based on current screening tests and may benefit from this treatment. Further study is required.

Occurrence of Focal Atrial Tachycardia During the Ablation Procedure Is Associated With Arrhythmia Recurrence After Termination of Persistent Atrial Fibrillation.

INTRODUCTION: Catheter ablation can terminate persistent atrial fibrillation (AF). However, atrial tachycardia (AT) often arises after termination of AF. METHODS AND RESULTS: Of 215 patients who underwent index stepwise ablation for persistent AF, 141 (66%) patients (64 ± 9 years) in whom AF terminated during the ablation procedure were studied. If AF converted into AT, ablation for AT was subsequently performed. ATs were categorized as focal or macroreentrant AT. We assessed whether type of AT occurring after conversion of AF during the ablation procedure was associated with freedom from atrial tachyarrhythmia (AF or AT) during follow-up. Sinus rhythm was directly restored from AF in 37 patients, while 34, 37, and 33 patients had focal AT alone, a mix of focal and macroreentrant AT, and macroreentrant AT alone after termination of AF, respectively. Arrhythmia-free survival rates at 1 year after the index procedure were 30%, 34%, 61%, and 59% in the patients with focal AT alone, a mix of focal AT and macroreentrant AT, macroreentrant AT alone, and direct restoration of sinus rhythm, respectively (P = 0.004). Type of AT occurring during the index procedure was associated with type of recurrent AT (P = 0.03), but the origin of focal AT occurring during the index ablation differed from that of the recurrent AT in 85% of patients. CONCLUSION: In patients who had AF termination by ablation, occurrence of focal AT during the ablation procedure was associated with worse clinical outcome than occurrence of macroreentrant AT, likely due to ATs arising from other foci during follow-up.

Impact of Non-Pulmonary Vein Foci on the Outcome of the Second Session of Catheter Ablation for Paroxysmal Atrial Fibrillation.

BACKGROUND: Paroxysmal atrial fibrillation (AF) is primarily triggered by pulmonary veins (PVs). However, non-PV AF foci may also trigger AF. METHODS: We examined 207 patients (mean age, 62 ± 11 years; 166 men) who underwent a second catheter ablation (CA) and evaluated the clinical significance of non-PV AF foci on the outcomes. RESULTS: Electrical reconnections between the PVs and left atrium (LA) were observed in 162 patients (78.3%). Non-PV AF foci were identified in 95 patients (45.9%, 60 patients with successfully ablated non-PV AF foci and 35 with unmappable non-PV AF foci). During a median follow-up period of 22.7 months, 61 patients (29.5%; 18/112 [16.1%] without non-PV AF foci vs. 20/60 [33.3%] with successfully ablated non-PV AF foci vs. 23/35 [65.7%] with unmappable non-PV AF foci, P < 0.0001) developed AF recurrence; 52 (85.2%) developed recurrence within 1 year. The presence of non-PV AF foci was a significant clinical predictor of AF recurrence after the second CA; successfully ablated non-PV AF foci increased the AF recurrence risk by 2.24 times (95% confidence interval [CI], 1.12-4.54; P = 0.02), and unmappable AF foci increased this risk by 5.58 times (95% CI, 2.73-11.63; P < 0.0001). CONCLUSION: Nearly half of the patients had non-PV AF foci at the second CA session. AF recurred after the second CA session in approximately 30%, with most recurrences happening within 1 year. The presence of non-PV AF foci significantly increased the AF recurrence risk after a second CA. When non-PV AF foci were unmappable, the AF recurrence rate was extremely high.

Incidences of esophageal injury during esophageal temperature monitoring: a comparative study of a multi-thermocouple temperature probe and a deflectable temperature probe in atrial fibrillation ablation.

PURPOSE: The study aim was to compare the incidence of esophageal injuries between different temperature probes in the monitoring of esophageal temperature during atrial fibrillation (AF) ablation. METHODS: One hundred patients with drug-resistant AF were prospectively and randomly assigned into two groups according to the esophageal temperature probe used: the multi-thermocouple probe group (n = 50) and the deflectable temperature probe group (n = 50). Extensive pulmonary vein (PV) isolation was performed with a 3.5-mm open irrigated tip ablation catheter by using a radiofrequency (RF) power of 25-30 W. In both groups, the esophageal temperature thermocouple was placed on the area of the esophagus adjacent to the ablation site. When the esophageal temperature reached 42 °C, the RF energy delivery was stopped. Esophageal endoscopy was performed 1 day after the catheter ablation. RESULTS: No differences existed between the two groups in terms of clinical background and various parameters related to the catheter ablation, including RF delivery time and number of RF deliveries at an esophageal temperature of >42 °C. Esophageal lesions, such as esophagitis and esophageal ulcers, occurred in 10/50 (20 %) and 15/50 (30 %) patients in the multi-thermocouple and deflectable temperature probe groups, respectively (P = 0.25). Most lesions were mild to moderate injuries, and all were cured using conservative treatment. CONCLUSION: The incidence of esophageal injury was almost equal between the multi-thermocouple temperature probe and the deflectable temperature probe during esophageal temperature monitoring. Most of the esophageal lesions that developed during esophageal temperature monitoring were mild to moderate and reversible.

Assessment of clinical factors associated with a successful catheter ablation outcome in younger patients with atrial fibrillation.

BACKGROUND: Catheter ablation is now an alternative approach to antiarrhythmic drug therapy for patients with symptomatic atrial fibrillation (AF). We focused on younger patients in whom the prevalence of AF is low, and we sought clinical factors associated with unsuccessful ablation outcomes. METHODS AND RESULTS: Among 1983 consecutive symptomatic patients who underwent AF ablation procedures, 95 patients (4.8%), age ≤ 40 years, were prospectively included. Of them, 64 had paroxysmal AF, and the remaining 31 had persistent AF. All patients underwent pulmonary vein isolation and cavotricuspid isthmus ablation. When AF recurred, redo ablations were performed if the patients desired. The mean number of ablation procedures was 1.3 ± 0.6 times per patient. During the follow-up of 40 [27.8-49.6] months, sinus rhythm was maintained in 86 patients (90.5%) without any antiarrhythmic drugs, but not in the remaining 9 patients (9.5%). Low body mass index (BMI) and persistent AF were associated with unsuccessful ablation procedures. In multivariate logistic regression analysis, a low BMI had the most significant value, with an odds ratio of 7.33 (p=0.022). The receiver operating characteristic curve demonstrated a BMI cut point of 22.1 kg/m(2), with an area under the curve of 0.773. CONCLUSION: In symptomatic younger AF patients, a low BMI was an independent clinical factor for unsuccessful AF ablation outcomes.

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

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.

Prevalence, electrophysiological properties, and clinical implications of dissociated pulmonary vein activity following pulmonary vein antrum isolation.

The objective of this study was to investigate the prevalence, electrophysiologic properties, and clinical implications of dissociated pulmonary vein (PV) activity after PV antrum isolation (PVAI) in patients with paroxysmal atrial fibrillation (AF). One hundred seventy-three consecutive patients (61 ±10 years old, 141 men) with drug-refractory paroxysmal AF who underwent AF ablation were analyzed. After identification of arrhythmogenic foci, PVAI was performed in all patients. Of the total 346 isolated ipsilateral PVs, 97 (28.0%) were silent, 35 (10.1%) demonstrated isolated ectopic beats, 209 (60.4%) demonstrated a regular ectopic rhythm, and 5 (1.4%) demonstrated fibrillatory activity. The culprit thoracic vein was identified in 77 patients (44.5%). After isolation of ipsilateral PVs, venous activity was observed in 68 (79.1%) and 178 (68.5%) PVs among the 86 PVs with AF triggers and 260 PVs without AF triggers, respectively (p = 0.06). There was no significant difference in the incidence of acute PV reconnections exposed by adenosine triphosphate between the 97 silent ipsilateral PVs and 209 ipsilateral PVs with dissociated PV activity after the PVAI (20.6% vs 19.1%, p = 0.78). After a mean follow-up of 48.7 ± 7.9 months there was no significant difference in rates of freedom from atrial tachyarrhythmias after a single procedure between patients with and those without dissociated activity (62.1% vs 63.3%, p = 0.74, log-rank test). In conclusion, although dissociated PV activity appearing after PV isolation is an important electrophysiologic finding to prove bidirectional conduction block between the left atrium and the PV during the procedure, the clinical implications might be limited.

Clinical characteristics of patients with persistent atrial fibrillation successfully treated by left atrial ablation.

BACKGROUND: We sought to characterize patients with persistent atrial fibrillation (AF) who were successfully treated by ablation targeting the left atrium (LA). METHODS AND RESULTS: Ninety-three patients (58±10 years, 79 male) undergoing ablation of persistent AF were studied. During the first procedure, ablation was performed in the LA and coronary sinus, consisting of pulmonary vein isolation, linear ablation, and electrogram-based ablation. During follow-up after the first procedure, 35 patients (38%) remained free from tachyarrhythmias, 27 patients (29%) had atrial tachycardia, and 31 patients (33%) had AF. Duration of persistent AF according to medical history and whether AF was terminated by ablation were associated with the outcome (P=0.005, P=0.004, respectively). In multivariate analysis, the duration of persistent AF was the only predictor of freedom from AF (sinus rhythm or atrial tachycardia) (odds ratio, 0.80 for a 1-year increase; 95% confidence interval, 0.67 to 0.95; P=0.01). Of 31 patients in whom AF recurred during follow-up, electrogram-based ablation was performed in the right atrium in 26 patients. Sixteen of those patients (62%) remained free from AF during follow-up. Overall, 82% of patients were free from any tachyarrhythmias at 2-year follow-up after a median of 2 procedures. CONCLUSIONS: Patients with shorter duration of persistent AF were more likely to be free from AF by LA ablation. Right atrial ablation may provide incremental efficacy in patients who are refractory to LA ablation.