Proven isolation of the pulmonary vein antrum with or without left atrial posterior wall isolation in patients with persistent atrial fibrillation.

BACKGROUND: It is unclear whether isolation of the left atrial posterior wall (LAPW) offers additional benefits over pulmonary vein antrum isolation (PVAI) alone in patients with persistent atrial fibrillation (AF). OBJECTIVE: We sought to determine the impact of PVAI and LAPW isolation (PVAI+LAPW) versus PVAI alone on the outcome of ablation of persistent AF. METHODS: During the first procedure, PVAI was performed in 20 patients (group 1), whereas in 32 patients (group 2), PVAI was extended to the left atrial (LA) septum and coronary sinus (CS), and isolation of the LAPW was targeted (ePVAI+LAPW). Isolation of the superior vena cava was achieved in both groups. All patients, regardless of arrhythmia recurrence, underwent a second procedure 3 months after the first procedure. In patients with reconnection of pulmonary veins or LAPW, reisolation was performed, and a third procedure was performed 3 months later to verify isolation. Patients entered follow-up only after PVAI (group 1) or PVAI+LAPW (group 2) isolation was proven. RESULTS: At the 1-, 2-, and 3-year follow-up examinations, the rates of freedom from atrial tachyarrhythmia without use of an antiarrhythmic drug were 20%, 15%, and 10% in group 1 and 65%, 50%, and 40% in group 2, respectively (log-rank P < .001). The median recurrence-free survival time was 8.5 months (interquartile range 6.5-11.0) in group 1 and 28.0 months (interquartile range 8.5-32.0) in group 2. CONCLUSION: Proven isolation of the LAPW provides additional benefits over PVAI alone in the treatment of persistent AF and improves procedural outcome at follow-up. However, the ablation strategy of ePVAI+LAPW is still associated with a significant high incidence of very late recurrence of atrial tachyarrhythmia. CLINICAL TRIAL REGISTRATION: "Outcome of Atrial Fibrillation Ablation After Permanent Pulmonary Vein Antrum Isolation With or Without Proven Left Atrial Posterior Wall Isolation" (LIBERATION). ClinicalTrials.gov Identifier: NCT01660100.

Catheter ablation of atrial fibrillation in patients with mechanical mitral valve: long-term outcome of single procedure of pulmonary vein antrum isolation with or without nonpulmonary vein trigger ablation.

INTRODUCTION: It is unclear whether extended pulmonary vein antrum isolation (PVAI) plus nonpulmonary vein (non-PV) trigger elimination prevents more arrhythmia recurrence than PVAI alone in patients with mechanical mitral valve (MMV) undergoing AF ablation. This study compared the efficacy and long-term outcome of 2 ablation strategies--PVAI alone versus extended PVAI plus non-PV trigger elimination--for the treatment of AF in patients with MMV. METHODS AND RESULTS: One hundred and nine consecutive AF patients with MMV were divided into 2 groups: standard PVAI was performed in group 1 (N = 45); in group 2 (N = 64) PVAI was extended to the LA posterior wall, LA septum, and CS; and all non-PV triggers were eliminated. Patients were followed up for 3 years. At the 12th month, 7 (15.6%) patients in group 1, and 39 (60.9%) patients in group 2 were arrhythmia free (log-rank P < 0.001). Four patients (8.9%; 3 cases of AT and 1 case of AF) from group 1, and 12 patients (18.8%; 9 cases of AT, and 3 cases of AFL) from group 2 experienced very late recurrence. At 36 ± 7 months follow-up, the cumulative recurrence after a single procedure was 42/45 (93.3%) in group 1, and 37/64 (57.8%) in group 2 (log-rank P < 0.001). CONCLUSION: Compared with the standard PVAI alone, a strategy including extended PVAI and non-PV trigger elimination is associated with a higher 12-month and long-term arrhythmia-free survival in patients with MMV undergoing AF ablation. Very late recurrence may occur years after the initial procedure with focal AT as the most common type of recurrent arrhythmia.

Endo-epicardial homogenization of the scar versus limited substrate ablation for the treatment of electrical storms in patients with ischemic cardiomyopathy.

OBJECTIVES: This study investigated the impact on recurrences of 2 different substrate approaches for the treatment of these arrhythmias. BACKGROUND: Catheter ablation of electrical storms (ES) for ventricular arrhythmias (VAs) has shown moderate long-term efficacy in patients with ischemic cardiomyopathy. METHODS: Ninety-two consecutive patients (81% male, age 62 ± 13 years) with ischemic cardiomyopathy and ES underwent catheter ablation. Patients were treated either by confining the radiofrequency lesions to the endocardial surface with limited substrate ablation (Group 1, n = 49) or underwent endocardial and epicardial ablation of abnormal potentials within the scar (homogenization of the scar, Group 2, n = 43). Epicardial access was obtained in all Group 2 patients, whereas epicardial ablation was performed in 33% (14) of these patients. RESULTS: Mean ejection fraction was 27 ± 5. During a mean follow-up of 25 ± 10 months, the VAs recurrence rate of any ventricular tachycardia (VTs) was 47% (23 of 49 patients) in Group 1 and 19% (8 of 43 patients) in Group 2 (log-rank p = 0.006). One patient in Group 1 and 1 patient in Group 2 died at follow-up for noncardiac reasons. CONCLUSIONS: Our study demonstrates that ablation using endo-epicardial homogenization of the scar significantly increases freedom from VAs in ischemic cardiomyopathy patients.

Correlation between signal-averaged ECG and the histologic evaluation of the myocardial substrate in right ventricular outflow tract arrhythmias.

BACKGROUND: The differential diagnosis between idiopathic and cardiomyopathy-related right ventricular outflow tract (RVOT) ventricular arrhythmias (VAs) is crucial. Signal-averaged ECG (SAECG) abnormalities are frequent in cardiomyopathy-related RVOT-VAs, although their pathophysiologic basis and diagnostic value in this setting are undefined. We tested the association between SAECG and the myocardial substrate underlying RVOT-VAs. METHODS AND RESULTS: Twenty-four consecutive patients (median age, 50 years [42-59]; 12 men) with RVOT-VAs (10 with frequent [>1000/24 hours] premature ventricular contractions, 14 with ventricular tachycardias) underwent SAECG with 40-Hz filtering and electroanatomic mapping (EAM) with EAM-guided biopsy for characterization of the RVOT-VAs substrate. A filtered averaged QRS (fQRS) was obtained and analyzed for fQRS duration, low amplitude signal duration<40 mV (LAS40), and root-mean-square voltage in the last 40 ms of the QRS (RMS40). Standard definition of EAM scar was used. EAM-guided biopsy diagnosed ARVC in 11 (46%), myocarditis in 8 (33%), and idiopathic RVOT-VAs in 5 (21%) patients. Patients with cardiomyopathy-related RVOT-VAs had ≥1 EAM scar (median, 2 [1-2]; all with RVOT scar). EAM of patients with idiopathic RVOT-VAs was normal. Patients with cardiomyopathy-related RVOT-VAs had significantly longer fQRS (106 ms [92-132] versus 83 ms [82-84], P=0.01) and LAS40 (39 ms [36-51] versus 19 ms [18-21], P=0.02), and lower RMS40 (18 µV [9-26] versus 33 µV [32-33], P=0.04). A significant linear correlation was found between the extension (cm2) of the RVOT scar and all 3 SAECG parameters (rs=0.76, P<0.001 for the fQRSd; rs=0.73, P<0.001 for the LAS40; and rs=-0.72, P<0.001 for the RMS40). Using the established 2 of 3 criteria (ie, late potentials), SAECG diagnosed cardiomyopathy-related RVOT-VAs with high positive (100%) but low negative (38%) predictive values and missed 7 of 9 (78%) patients with RVOT scar<8 cm2. CONCLUSIONS: In patients with RVOT-VAs, abnormal SAECG parameters reflect the presence of extensive cardiomyopathic involvement of the RVOT. However, a negative SAECG does not reliably rule out cardiomyopathy-related RVOT-VAs in the presence of a small RVOT scar.

Ablation of ventricular arrhythmias in arrhythmogenic right ventricular dysplasia/cardiomyopathy: arrhythmia-free survival after endo-epicardial substrate based mapping and ablation.

BACKGROUND: In patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy, freedom from ventricular arrhythmias (VAs) after endocardial ablation is limited. We compared the long-term freedom from recurrent VAs by using endocardial-alone ablation versus endo-epicardial substrate-based ablation. METHODS AND RESULTS: Forty-nine patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy undergoing ablation of ventricular tachycardia (VT) were divided into 2 groups: endocardial-alone ablation (group 1, n = 23) and endo-epicardial ablation (group 2, n = 26). All patients had an implantable cardioverter-defibrillator (ICD). Conventional and 3D mappings were used to determine the mechanism of induced VTs and to identify area of "scar" or "abnormal" myocardium. All critical sites responsible for VTs and points with "abnormal" potential were targeted for ablation from endocardium (group 1) or from both endocardium and epicardium (group 2). The procedural end point was noninducibility of sustained, monomorphic VT with isoproterenol. The presence of frequent premature ventricular contractions at the end of ablation was recorded. Patients were followed up by ECG, Holter, and ICD interrogation. After a follow-up of at least 3 years, freedom from VAs or ICD therapy was 52.2% (12/23) in group 1 and 84.6% (22/26) in group 2 (P = 0.029), with 21.7% (5/23) and 69.2% (18/26) patients off antiarrhythmic drugs (P < 0.001), respectively. Compared with patients with no premature ventricular contractions after ablation, patients with frequent premature ventricular contractions after ablation were more likely to have VA recurrence/ICD therapy [3/33 (9%) versus 12/16 (75%); log-rank P<0.001]. CONCLUSIONS: An endo-epicardial-based ablation strategy achieves higher long-term freedom from recurrent VAs off antiarrhythmic therapy in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy when compared with endocardial-alone ablation. The presence of ≥ 10 premature ventricular contractions per minute after ablation is associated with more VA recurrence.

Cardiac resynchronization therapy in patients with mild heart failure: a systematic review and meta-analysis.

PURPOSE: Cardiac resynchronization therapy (CRT) reduces symptoms and improves survival in patients with advanced heart failure (New York Heart Association (NYHA) functional class III-IV), reduced ejection fraction, and wide QRS complex. Whether CRT has the same benefit also in asymptomatic or mildly symptomatic heart failure patients is controversial. Our objective is to summarize the available evidence on the effects of CRT in asymptomatic or mildly symptomatic (NYHA I-II) heart failure patients. METHODS: We searched major web databases for randomized controlled trials of CRT in patients with mild heart failure (NYHA functional class I-II). Data regarding all-cause mortality, heart failure events, left ventricular (LV) volumes and ejection fraction, and worsening of NYHA functional class were extracted. RESULTS: We identified five trials (CONTAK-CD, MIRACLE ICD-II, REVERSE, MADIT-CRT, and RAFT) that enrolled 4,213 patients (91% with NYHA II functional class). Primary analysis excluded the CONTAK-CD, which was not specifically conducted on patients with mild heart failure. At pooled analysis, CRT decreased mortality (odds ratio (OR), 0.78 [95% confidence interval (CI)], 0.63 to 0.97; p = 0.024) and heart failure events (OR, 0.63 [95% CI, 0.52 to 0.76], p < 0.001), induced a significant LV reverse remodeling (weighted mean difference (WMD) of LV ejection fraction [Formula: see text], p = 0.015 and WMD of LV end-systolic volume index [Formula: see text], p < 0.001) and prevented the progression of heart failure symptoms (OR for worsening of NYHA functional class = 0.54 [95% CI, 0.31 to 0.93], p = 0.026). Inclusion of the CONTAK-CD did not change the results. CONCLUSIONS: Among patients with mild (NYHA II) heart failure, CRT reduces mortality and the risk of heart failure events, induces a favorable LV reverse remodeling and slows the progression of heart failure symptoms.

Meta-analysis: age and effectiveness of prophylactic implantable cardioverter-defibrillators.

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) for the primary prevention of sudden cardiac death have been proven effective in several clinical trials. PURPOSE: To summarize evidence about the effectiveness of ICDs versus standard medical therapy for the primary prevention of sudden cardiac death in different age groups of patients with severe left ventricular dysfunction. DATA SOURCES: MEDLINE, Embase, CENTRAL, BioMed Central, Cardiosource, ClinicalTrials.gov, and ISI Web of Science (January 1970 to April 2010) were searched with no language restrictions. STUDY SELECTION: Two independent reviewers screened titles and abstracts to identify randomized, controlled trials of prophylactic ICD versus medical therapy in patients with severe left ventricular dysfunction that provided data about mortality outcomes for different age groups. DATA EXTRACTION: Two independent reviewers assessed risk for bias of trials and extracted patient and study characteristics and hazard ratios (HRs) relevant to all-cause mortality. DATA SYNTHESIS: Five trials (MADIT-II, DEFINITE, DINAMIT, SCD-HeFT, and IRIS) that enrolled 5783 patients (44% were elderly) were included. The primary analysis, which excluded the 2 trials enrolling patients early after acute myocardial infarction (DINAMIT and IRIS), found that prophylactic ICD therapy reduced mortality in younger patients (HR, 0.65 [95% CI, 0.50 to 0.83]; P < 0.001). A smaller survival benefit was found in elderly patients (HR, 0.75 [95% CI, 0.61 to 0.91]) that was not confirmed when MADIT-II patients older than 70 years were excluded or when data from DINAMIT and IRIS were included [corrected]. LIMITATIONS: Four potentially eligible trials were not included in the meta-analysis because mortality data by age group were not available. Adjustment for differences in comorbid conditions and medical therapies among patients enrolled in the trials was not possible. CONCLUSION: Available data suggest that prophylactic ICD therapy may be less beneficial for elderly patients with severe left ventricular dysfunction than for younger patients [corrected]. PRIMARY FUNDING SOURCE: None.

Left atrial appendage: an underrecognized trigger site of atrial fibrillation.

BACKGROUND: Together with pulmonary veins, many extrapulmonary vein areas may be the source of initiation and maintenance of atrial fibrillation. The left atrial appendage (LAA) is an underestimated site of initiation of atrial fibrillation. Here, we report the prevalence of triggers from the LAA and the best strategy for successful ablation. METHODS AND RESULTS: Nine hundred eighty-seven consecutive patients (29% paroxysmal, 71% nonparoxysmal) undergoing redo catheter ablation for atrial fibrillation were enrolled. Two hundred sixty-six patients (27%) showed firing from the LAA and became the study population. In 86 of 987 patients (8.7%; 5 paroxysmal, 81 nonparoxysmal), the LAA was found to be the only source of arrhythmia with no pulmonary veins or other extrapulmonary vein site reconnection. Ablation was performed either with focal lesion (n=56; group 2) or to achieve LAA isolation by placement of the circular catheter at the ostium of the LAA guided by intracardiac echocardiography (167 patients; group 3). In the remaining patients, LAA firing was not ablated (n=43; group 1). At the 12+/-3-month follow-up, 32 patients (74%) in group 1 had recurrence compared with 38 (68%) in group 2 and 25 (15%) in group 3 (P<0.001). CONCLUSIONS: The LAA appears to be responsible for arrhythmias in 27% of patients presenting for repeat procedures. Isolation of the LAA could achieve freedom from atrial fibrillation in patients presenting for a repeat procedure when arrhythmias initiating from this structure are demonstrated.

Periprocedural stroke and management of major bleeding complications in patients undergoing catheter ablation of atrial fibrillation: the impact of periprocedural therapeutic international normalized ratio.

BACKGROUND: Catheter ablation of atrial fibrillation is associated with the potential risk of periprocedural stroke, which can range between 1% and 5%. We developed a prospective database to evaluate the prevalence of stroke over time and to assess whether the periprocedural anticoagulation strategy and use of open irrigation ablation catheter have resulted in a reduction of this complication. METHODS AND RESULTS: We collected data from 9 centers performing the same ablation procedure with the same anticoagulation protocol. We divided the patients into 3 groups: ablation with an 8-mm catheter off warfarin (group 1), ablation with an open irrigated catheter off warfarin (group 2), and ablation with an open irrigated catheter on warfarin (group 3). Outcome data on stroke/transient ischemic attack and bleeding complications during and early after the procedures were collected. Of 6454 consecutive patients in the study, 2488 were in group 1, 1348 were in group 2, and 2618 were in group 3. Periprocedural stroke/transient ischemic attack occurred in 27 patients (1.1%) in group 1 and 12 patients (0.9%) in group 2. Despite a higher prevalence of nonparoxysmal atrial fibrillation and more patients with CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score >2, no stroke/transient ischemic attack was reported in group 3. Complications among groups 1, 2, and 3, including major bleeding (10 [0.4%], 11 [0.8%], and 10 [0.4%], respectively; P>0.05) and pericardial effusion (11 [0.4%], 11 [0.8%], and 12 [0.5%]; P>0.05), were equally distributed. CONCLUSIONS: The combination of an open irrigation ablation catheter and periprocedural therapeutic anticoagulation with warfarin may reduce the risk of periprocedural stroke without increasing the risk of pericardial effusion or other bleeding complications.

Radiofrequency catheter ablation of ventricular arrhythmias in patients with hypertrophic cardiomyopathy: safety and feasibility.

BACKGROUND: Management of ventricular tachycardia (VT) in patients with hypertrophic cardiomyopathy (HCM) is challenging. OBJECTIVE: The purpose of this study is to assess the value of radiofrequency catheter ablation (RFCA) for the treatment of the VTs in the setting of HCM. METHODS: Twenty-two patients (18 with ICD) with HCM and multiple episodes of VTs resistant to medical therapy underwent RFCA with an open irrigation catheter. Epicardial access was obtained if required. All patients were followed for at least 1 year after RFCA. RESULTS: Mean age was 50.4 +/- 15.3, and mean ejection fraction was 34.3% +/- 9.8%. RFCA was performed endocardially in all patients, while epicardial radiofrequency applications were needed in 13 patients. A previous endocardial ablation was unsuccessful in six patients. At 20 +/- 9 months of follow-up, elimination of VTs reached 73%. No major complication was observed during and after the procedures in all patients. CONCLUSION: Catheter ablation of VTs in patients with hypertrophic cardiomyopathy refractory to medical therapy is safe, feasible, and successful in eliminating VT. Epicardial VT mapping and ablation should be considered as an important access option for the treatment of these patients to increase the success rate.

Gender differences in clinical outcome and primary prevention defibrillator benefit in patients with severe left ventricular dysfunction: a systematic review and meta-analysis.

BACKGROUND: Women are underrepresented in primary prevention implantable cardioverter-defibrillator (ICD) trials, and data on the benefit of ICD therapy in this subgroup are controversial. OBJECTIVE: The purpose of this study was to better evaluate the benefit of prophylactic ICD in women by performing a meta-analysis of primary prevention ICD trials that assessed gender differences on the end-points of total mortality, appropriate ICD intervention, and survival benefit of ICD compared with placebo. METHODS: PubMed, CENTRAL, and other databases were searched in October 2009. Studies were included only if they examined gender differences in the specified end-points, providing the hazard ratio (HR) obtained in multiple Cox regression analyses, and adjusted for all confounding variables. RESULTS: We retrieved five studies (MADIT-II, MUSTT, SCD-HeFT, DEFINITE, COMPANION) that enrolled 7,229 patients (22% women) with dilated cardiomyopathy (74% ischemic). Compared to men, women had no significant difference in overall mortality (HR 0.96, 95% confidence interval [CI] 0.67-1.39, P = .84) but experienced significantly less appropriate ICD interventions (HR 0.63, 95% CI 0.49-0.82, P < or =.001). The benefit of ICD on mortality was significantly higher in men (HR 0.67, 95% CI 0.58-0.78, P <.001) but did not reach statistical significance in women (HR 0.78, 95% CI 0.57-1.05, P = .1). CONCLUSION: Women enrolled in primary prevention ICD trials have the same mortality compared to men while experiencing significantly less appropriate ICD interventions, thus suggesting a smaller impact of sudden cardiac death on overall mortality in women with dilated cardiomyopathy. These findings may explain the smaller ICD survival benefit among women.

Atrial fibrillation ablation strategies for paroxysmal patients: randomized comparison between different techniques.

BACKGROUND: Whether different ablation strategies affect paroxysmal atrial fibrillation (AF) long-term freedom from AF/atrial tachyarrhythmia is unclear. We sought to compare the effect of 3 different ablation approaches on the long-term success in patients with paroxysmal AF. METHODS AND RESULTS: One hundred three consecutive patients with paroxysmal AF scheduled for ablation and presenting in the electrophysiology laboratory in AF were selected for this study. Patients were randomized to pulmonary vein antrum isolation (PVAI; n=35) versus biatrial ablation of the complex fractionated atrial electrograms (CFAEs; n=34) versus PVAI followed by CFAEs (n=34). Patients were given event recorders and followed up at 3, 6, 9, 12, and 15 months postablation. There was no statistical significant difference between the groups in term of sex, age, AF duration, left atrial size, and ejection fraction. At 1 year follow-up, freedom from AF/atrial tachyarrhythmia was documented in 89% of patients in the PVAI group, 91% in the PVAI plus CFAEs group, and 23% in the CFAEs group (P<0.001) after a single procedure and with antiarrhythmic drugs. CONCLUSIONS: No difference in terms of success rate was seen between PVAI alone and PVAI associated with defragmentation. CFAEs ablation alone had the smallest impact on AF recurrences at 1-year follow-up. These results suggest that antral isolation is sufficient to treat most patients with paroxysmal AF.

Prevention of phrenic nerve injury during epicardial ablation: comparison of methods for separating the phrenic nerve from the epicardial surface.

BACKGROUND: The proximity of the phrenic nerve (PN) to cardiac tissue relevant to arrhythmias may increase the risk of PN injury. Strategies for preventing PN injury in the pericardial space are limited. OBJECTIVE: The purpose of this study was to compare methods for separating the PN from the epicardial surface in order to prevent PN injury. METHODS: Eight patients referred for epicardial ablation of arrhythmias were enrolled in the study. All patients required ablation near the PN. Endocardial and epicardial access was obtained in all patients. A three-dimensional mapping system was used to guide mapping and ablation. All patients underwent epicardial catheter ablation. Pacing via the ablation catheter identified the location of the PN. In order to prevent PN injury, four new strategies were tested in each patient. We sought to increase the distance between the epicardium and the PN by (1) placing a large-diameter balloon between the nerve and the myocardium, (2) introducing saline in steps of 20 ml until PN capture was lost or blood pressure dropped below 60 mmHg, (3) introducing air until PN capture was lost or blood pressure dropped below 60 mmHg, or (4) introducing a combination of saline and air until PN capture was lost or blood pressure dropped below 60 mmHg. RESULTS: At each step, epicardial pacing was performed to assess for PN stimulation. The combination of air and saline resulted in the greatest decrease of PN stimulation. Saline only failed in all cases. Air only and balloon placement were infrequently successful. CONCLUSION: Controlled and progressive inflation of air and saline together with careful monitoring of hemodynamic parameters appears to be the best strategy for preventing PN injury during epicardial ablation. Placement of a large balloon in the appropriate location can be difficult.

Ablation for longstanding permanent atrial fibrillation: results from a randomized study comparing three different strategies.

BACKGROUND: This prospective multicenter randomized study aimed to compare the efficacy of 3 common ablation methods used for longstanding permanent atrial fibrillation (AF). METHODS: A total of 144 patients with longstanding permanent AF (median duration 28 months) were randomly assigned to circumferential pulmonary vein ablation (CPVA, group 1, n = 47), to pulmonary vein antrum isolation (PVAI, group 2, n = 48) or to a hybrid strategy combining ablation of complex fractionated or rapid atrial electrograms (CFAE) in both atria followed by a pulmonary vein antrum isolation (CFAE + PVAI, group 3, n = 49). RESULTS: Scarring in the left atrium and structural heart disease/hypertension were present in most patients (65%). After a mean follow-up of 16 months, 11% of patients in group 1, 40% of patients in group 2 and 61% of patients in group 3 were in sinus rhythm after one procedure and with no antiarrhythmic drugs (P < .001). Sinus rhythm maintenance would increase respectively to 28% (group 1), 83% (group 2), and 94% (group 3) after 2 procedures and with antiarrhythmic drugs (AADs, P < .001). The AF terminated during ablation, either by conversion to sinus rhythm or organization into an atrial tachyarrhythmia, in 13% of patients (group 1), 44% (group 2), and 74% (group 3) respectively. CFAE alone, performed as the first step of the ablation in group 3, organized AF in only 1 patient. CONCLUSION: In this study, the hybrid AF ablation strategy including antrum isolation and CFAE ablation had the highest likelihood of maintaining sinus rhythm in patients with longstanding permanent AF. Electrical isolation of the PVs, although inadequate if performed alone, is relevant to achieve long-term sinus rhythm maintenance after ablation. Bi-atrial CFAE ablation had a minimal impact on AF termination during ablation.

Pulmonary-vein isolation for atrial fibrillation in patients with heart failure.

BACKGROUND: Pulmonary-vein isolation is increasingly being used to treat atrial fibrillation in patients with heart failure. METHODS: In this prospective, multicenter clinical trial, we randomly assigned patients with symptomatic, drug-resistant atrial fibrillation, an ejection fraction of 40% or less, and New York Heart Association class II or III heart failure to undergo either pulmonary-vein isolation or atrioventricular-node ablation with biventricular pacing. All patients completed the Minnesota Living with Heart Failure questionnaire (scores range from 0 to 105, with a higher score indicating a worse quality of life) and underwent echocardiography and a 6-minute walk test (the composite primary end point). Over a 6-month period, patients were monitored for both symptomatic and asymptomatic episodes of atrial fibrillation. RESULTS: In all, 41 patients underwent pulmonary-vein isolation, and 40 underwent atrioventricular-node ablation with biventricular pacing; none were lost to follow-up at 6 months. The composite primary end point favored the group that underwent pulmonary-vein isolation, with an improved questionnaire score at 6 months (60, vs. 82 in the group that underwent atrioventricular-node ablation with biventricular pacing; P<0.001), a longer 6-minute-walk distance (340 m vs. 297 m, P<0.001), and a higher ejection fraction (35% vs. 28%, P<0.001). In the group that underwent pulmonary-vein isolation, 88% of patients receiving antiarrhythmic drugs and 71% of those not receiving such drugs were free of atrial fibrillation at 6 months. In the group that underwent pulmonary-vein isolation, pulmonary-vein stenosis developed in two patients, pericardial effusion in one, and pulmonary edema in another; in the group that underwent atrioventricular-node ablation with biventricular pacing, lead dislodgment was found in one patient and pneumothorax in another. CONCLUSIONS: Pulmonary-vein isolation was superior to atrioventricular-node ablation with biventricular pacing in patients with heart failure who had drug-refractory atrial fibrillation. (ClinicalTrials.gov number, NCT00599976.)

Pulmonary vein antral isolation using an open irrigation ablation catheter for the treatment of atrial fibrillation: a randomized pilot study.

OBJECTIVES: We sought to test how catheter ablation using an open irrigation catheter (OIC) compares with standard catheters for pulmonary vein antrum isolation. BACKGROUND: Open irrigation catheters have the advantage of delivering greater power without increasing the temperature of the catheter tip, which enables deeper and wider lesions without the formation of coagulum on catheters. METHODS: Catheter ablation was performed using an 8-mm catheter (8MC) or an OIC. Patients were randomized to 3 groups: 8MC; OIC-1, OIC with a higher peak power (50 W); and OIC-2, OIC with lower peak power (35 W). RESULTS: A total of 180 patients were randomized to the 3 treatment strategies. Isolation of pulmonary vein antra was achieved in all patients. The freedom from atrial fibrillation was significantly greater in the 8MC and OIC-1 groups compared with the OIC-2 group (78%, 82%, and 68%, respectively, p = 0.043). Fluoroscopy time was lower in OIC-1 compared with OIC-2 and 8MC (28 +/- 1 min, 53 +/- 2 min, and 46 +/- 2 min, respectively, p = 0.001). The mean left atrium instrumentation time was lower in the OIC-1 compared with the OIC-2 and 8MC groups (59 +/- 3 min, 90 +/- 5 min, and 88 +/- 4 min, respectively, p = 0.001). However, there was a greater incidence of "pops" in the OIC-1 (100%, 0%, 0%, p < 0.001) along with higher incidences of pericardial effusion (20%, 0%, 0%, p < 0.001) and gastrointestinal complaints (17% in OIC-1, 3% in 8MC, and 5% in OIC-2, p = 0.031). CONCLUSIONS: Although there was a decrease in fluoroscopy and left atrium instrumentation time with the use of OIC at higher power, this setting was associated with increased cardiovascular and gastrointestinal complications.

Immunohistochemical-scintigraphic correlation of sympathetic cardiac innervation in postischemic left ventricular aneurysms.

BACKGROUND: This study was conceived to explore the correspondence between scintigraphic imaging of the sympathetic innervation of human postischemic left ventricular aneurysms and direct immunohistochemical localization of the nerve fibers in the same area. MATERIALS AND METHODS: In 7 patients undergoing left ventricular aneurysmectomy for postischemic ventricular aneurysm, the findings of thallium 201 and metaiodobenzylguanidine myocardial scintigraphy were compared with direct immunohistochemical localization of the nerve fibers in the same area. This comparison showed good correspondence between scintigraphic and immunohistochemical data, although scintigraphy failed to detect areas of minimal sympathetic innervation. Moreover, microscopic analysis showed sympathetic nerve fibers with peculiar morphology and distribution in the aneurysmal zone. CONCLUSION: There is a good correspondence between immunohistochemical and scintigraphic imaging in the detection of sympathetic cardiac nerves in human left ventricular aneurysms; a morphologically abnormal sympathetic reinnervation can be found in the aneurysmal area (although denervation can persist in some zones).

Circumferential ultrasound ablation for pulmonary vein isolation: analysis of acute and chronic failures.

INTRODUCTION: In patients undergoing circumferential isolation of the pulmonary veins with an ultrasound ablation system, we analyzed the temperatures achieved while delivering circumferential ostial lesions in the pulmonary veins. We also reviewed the angiograms obtained during the procedure and identified anatomic variants that could be responsible for ineffective lesion formation. METHODS AND RESULTS: During the early clinical use in 33 patients, a total of 85 veins were ablated. A mean of 16.9 +/- 12.3 ablations were delivered per patient, and a mean of 6.7 ablations per vein were applied. Entry block was assessed by placing a deflectable octapolar or a circular catheter in the vein. The following anatomic characteristics and technical limitations were identified as possible reasons for ineffective energy delivery: (1) funnel-shaped ostium; (2) ostial diameter larger than the balloon diameter; (3) inability to deliver the catheter to the right inferior or other vein ostia; (4) ostial instability; (5) early branching of the vein; and (6) eccentric position of the ultrasound transducer in the vein. In patients with recurrence of atrial fibrillation, 40% of the ostial lesions reached a temperature >60 degrees C. However, in patients cured by the ablation, 64% of the ostial lesions reached a temperature >60 degrees C (P < 0.06). At least 12 of the 20 chronic recurrences could have been related to technical limitations of the first system. Duration of atrial fibrillation and eccentric deployment of the ultrasound transducer were more frequent in patients with recurrence of arrhythmias at follow-up. CONCLUSION: Ostial anatomy of the veins may affect delivery of ultrasound energy to achieve circumferential lesions. Energy delivery at the ostium with a temperature > 60 degrees C may be important to maximize success. Reconfiguration of the system to overcome the shortcomings identified in the initial experience could increase its performance.