Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Fibrillation

  • atrial fibrillation
  • chronic atrial fibrillation
  • focal atrial fibrillation
  • human atrial fibrillation
  • idiopathic ventricular fibrillation
  • nonvalvular atrial fibrillation
  • paroxysmal atrial fibrillation
  • permanent atrial fibrillation
  • persistent atrial fibrillation
  • postoperative atrial fibrillation
  • recurrent atrial fibrillation
  • refractory atrial fibrillation
  • ventricular fibrillation

  • Terms modified by Fibrillation

  • fibrillation ablation
  • fibrillation duration
  • fibrillation induction
  • fibrillation recurrence

  • Selected Abstracts


    Huai Yong Cheng MD
    No abstract is available for this article. [source]

    Association of Left Atrial Strain and Strain Rate Assessed by Speckle Tracking Echocardiography with Paroxysmal Atrial Fibrillation

    ECHOCARDIOGRAPHY, Issue 10 2009
    Wei-Chuan Tsai M.D.
    Background: We hypothesized that contraction of the LA wall could be documented by speckle tracking and could be applied for assessment of LA function. This study tried to identify the association between LA longitudinal strain (LAS) and strain rate (LASR) measured by speckle tracking with paroxysmal atrial fibrillation (PAF). Methods: Fifty-two patients (61 17 years old, 23 men) with sinus rhythm at baseline referred for the evaluation of episodic palpitation were included. Standard four-chamber and two-chamber views were acquired and analyzed off-line. Peak LAS and LASR were carefully identified as the peak negative inflection of speckle tracking waves after P-wave gated by electrocardiography. Results: Ten patients (19%) had PAF. LAS, LASR, age, left ventricular end-diastolic dimension, left ventricular mass, LA volume, and mitral early filling-to-annulus early velocity ratio were different between patients with and without PAF. After multivariate analysis, LASR was significantly independently associated with PAF (OR 8.56, 95% CI 1.14,64.02, P = 0.036). Conclusion: Speckle tracking echocardiography could be used in measurements of LAS and LASR. Decreased negative LASR was independently associated with PAF. [source]

    Mitral Regurgitation Associated with Mitral Annular Dilation in Patients with Lone Atrial Fibrillation: An Echocardiographic Study

    ECHOCARDIOGRAPHY, Issue 8 2009
    Takashi Kihara M.D.
    Background: Whether and how lone atrial fibrillation (AF) is associated with functional mitral regurgitation (MR) remain unclear. Method: We studied 12 lone AF patients without left ventricular (LV) dysfunction and/or dilatation, who underwent mitral valve annuloplasty for functional mitral regurgitation (MR). Ten lone AF patients without MR served as controls. Results: Lone AF Patients with MR had a greater mitral valve annular area and left atrial area than those without MR. There were no differences in LV volumes or LV ejection fraction. Conclusions: Therefore, we concluded that left atrial dilation and corresponding mitral annular dilation may cause MR in lone AF patients without LV dysfunction and/or dilatation. [source]

    IMAGE SECTION: Stunning of Left Atrial Appendage after Spontaneous Conversion of Atrial Fibrillation

    ECHOCARDIOGRAPHY, Issue 3 2008
    Mikko Savontaus M.D.
    No abstract is available for this article. [source]

    Predictors for Maintenance of Sinus Rhythm after Cardioversion in Patients with Nonvalvular Atrial Fibrillation

    ECHOCARDIOGRAPHY, Issue 5 2002
    kn M.D.
    Recurrence of atrial fibrillation (AF) after cardioversion (CV) to sinus rhythm (SR) is determined by various clinical and echocardiographic parameters. Transesophageal echocardiographic (TEE) parameters have been the focus of clinicians' interests for restoring and maintaining SR. This study determined the clinical, transthoracic, and TEE parameters that predict maintenance of SR in patients with nonvalvular AF after CV. We enrolled 173 patients with nonvalvular AF in the study. TEE could not be performed in 26 patients prior to CV. Twenty-five patients had spontaneously CV prior to TEE. Six patients were excluded because of left atrial (LA) thrombus assessed by TEE. CV was unsuccessful in 6 patients. The remaining 110 consecutive patients (56 men, 54 women, mean age 69 9 years), who had been successfully cardioverted to SR, were prospectively included in the study. Fifty-seven (52%) patients were still in SR 6 months after CV. Age, gender, the configuration of the fibrillation wave on the electrocardiogram, pulmonary venous diastolic flow, and the presence of diabetes, hypertension, coronary artery disease, mitral annulus calcification, and mitral valve prolapse (MVP) did not predict recurrence. Duration of AF, presence of chronic obstructive pulmonary disease (COPD), LA diameter, left ventricular ejection fraction (EF), left atrial appendage peak flow (LAAPF), LAA ejection fraction (LAAEF), pulmonary venous systolic flow (PVSF), and the presence of LA spontaneous echo contrast (LASEC) predicted recurrence of AF 6 months after CV. In multivariate analysis, LAAEF < 30% was found to be the only independent variable (P < 0.0012) predicting recurrence at 6 months after CV in patients with nonvalvular AF. LAAEF more than 30% had a sensitivity of 75% and a specificity of 88% in predicting maintenance of SR 6 months after CV in patients with nonvalvular AF. In conclusion, TEE variables often used to determine thromboembolic risk also might be used to predict the outcome of CV. [source]

    Effect of Inotropic Stimulation on Left Atrial Appendage Function in Atrial Myopathy of Chronic Atrial Fibrillation

    ECHOCARDIOGRAPHY, Issue 4 2000
    Atrial fibrillation (AF) leads to remodeling of the left atrium (LA) and left atrial appendage (LAA), resulting in atrial myopathy. Reduced LA and LAA function in chronic AF leads to thrombus formation and spontaneous echo contrast (SEC). The effect of inotropic stimulation on LAA function in patients with chronic AF is unknown. LAA emptying velocity (LAAEV) and maximal LAA area at baseline and after dobutamine were measured by transesophageal echocardiography in 14 subjects in normal sinus rhythm (NSR) and 6 subjects in AF. SEC in the LA was assessed before and after dobutamine. LAAEV increased significantly in both groups. However, the LAAEV at peak dobutamine in patients with AF remained significantly lower than the baseline LAAEV in patients who were in NSR (P= 0.009). Maximal LAA area decreased significantly with dobutamine in both groups, but LAA area at peak dose of dobutamine inpatients with AF remained greater than baseline area in those in NSR (P= 0.01). Despite the increase in LAAEV, SEC improved in only two of five patients. We conclude that during AF, the LAA responds to inotropic stimulation with only a modest improvement in function. [source]

    Role of Transthoracic Echocardiography in Atrial Fibrillation

    ECHOCARDIOGRAPHY, Issue 4 2000
    Atrial fibrillation is a major clinical problem that is predicted to be encountered more frequently as the population ages. The clinical management of atrial fibrillation has become increasingly complex as new therapies and strategies have become available for ventricular rate control, conversion to sinus rhythm, maintenance of sinus rhythm, and prevention of thromboembolism. Clinical and transthoracic echocardiographic features are important in determining etiology and directing therapy for atrial fibrillation. Left atrial size, left ventricular wall thickness, and left ventricular function have independent predictive value for determining the risk of developing atrial fibrillation. Left atrial size may have predictive value in determining the success of cardioversion and maintaining sinus rhythm in selected clinical settings but has less value in the most frequently encountered group, patients with nonvalvular atrial fibrillation, in whom the duration of atrial fibrillation is the most important feature. When selecting pharmacological agents to control ventricular rate, convert to sinus rhythm, and maintain normal sinus rhythm, transthoracic echocardiography (TTE) allows noninvasive evaluation of left ventricular function and hence guides management. The combination of clinical and transthoracic echocardiographic features also allows risk stratification for thromboembolism and hemorrhagic complications in atrial fibrillation. High-risk clinical features for thromboembolism supported by epidemiological observations, results of randomized clinical trials, and meta-analyses include rheumatic valvular heart disease, prior thromboembolism, congestive heart failure, hypertension, older (> 75 years old) women, and diabetes. Small series of cases also suggest those with hyperthyroidism and hypertrophic cardiomyopathy are at high risk. TTE plays a unique role in confirming or discovering high-risk features such as rheumatic valvular disease, hypertrophic cardiomyopathy, and decreased left ventricular function. Validation of the risk stratification scheme used in the Stroke Prevention in Atrial Fibrillation-III trial is welcomed by clinicians who are faced daily with balancing the benefit and risks of anticoagulation to prevent thromboembolism inpatients with atrial fibrillation. [source]

    Transesophageal Echocardiography Risk Factors for Stroke in Nonvalvular Atrial Fibrillation

    ECHOCARDIOGRAPHY, Issue 4 2000
    Atrial fibrillation is a common arrhythmia, particularly in the older age groups. It confers an increased risk of thromboembolism to these patients, and multiple clinical risk factors have been identified to be useful in predicting the risks of thromboembolic events. Recent studies have evaluated the role of transesophageal echocardiography (TEE) in the evaluation of patients with atrial fibrillation. The purpose of this review is to evaluate the significance of transesophageal echocardiography findings in the prediction of thromboembolic events, particularly stroke, in patients with nonvalvular atrial fibrillation, with an emphasis on recently reported prospective studies. Aortic plaque and left atrial appendage abnormalities are identified as independent predictors of thromboembolic events. Although they are associated with clinical events, they also have independent incremental prognostic values. Other transesophageal echocardiographic findings, such as patent foramen ovale and atrial septal aneurysm, have not been found to be predictors of thromboembolic events in this patient group. Thus, TEE is a useful tool in stratifying patients with nonvalvular atrial fibrillation into different risk groups in terms of thromboembolic events, and it will likely play an important role in future studies to assess new treatment strategies in high-risk patients with atrial fibrillation. [source]

    A Model of Ischemically Induced Ventricular Fibrillation for Comparison of Fixed-dose and Escalating-dose Defibrillation Strategies

    James T. Niemann MD
    Abstract Objectives: Fixed- and escalating-dose defibrillation protocols are both in clinical use. Clinical observations suggest that the probability of successful defibrillation is not constant across a population of patients with ventricular fibrillation (VF). Common animal models of electrically induced VF do not represent a clinical VF etiology or reproduce clinical heterogeneity in defibrillation probability. The authors hypothesized that a model of ischemically induced VF would exhibit heterogeneous defibrillation shock strength requirements and that an escalating-dose strategy would more effectively achieve prompt defibrillation. Methods:Forty-six swine were randomized to fixed, lower-energy (150 J) transthoracic shocks (group 1) or escalating, higher-energy (200 J,300 J,360 J) shocks (group 2). VF was induced by balloon occlusion of a coronary artery. After 1 or 5 minutes of VF, countershocks with a biphasic waveform were administered. The primary endpoint was successful defibrillation (termination of VF for 5 seconds) with ,3 shocks. Results: VF was induced with occlusion or after reperfusion in 35 animals. Only five of 17 group 1 animals (29%, 95% CI = 10 to 56) could be defibrillated with ,3 shocks; 15 of 18 group 2 animals (83%, 95% CI = 59 to 96) were defibrillated with ,3 shocks (p < 0.002 vs. group 1). Nine of the group 1 animals (75%) that could not be defibrillated with 150-J shocks were rescued with ,3 shocks ranging from 200 to 360 J. Conclusions: In this ischemic VF animal model, defibrillation shock strength requirements varied among individuals, and when defibrillation was difficult, an escalating-dose strategy was more effective for prompt defibrillation than fixed, lower-energy shocks. [source]

    Thirty-day Outcomes of Emergency Department Patients Undergoing Electrical Cardioversion for Atrial Fibrillation or Flutter

    Frank Xavier Scheuermeyer MD
    Abstract Objectives:, While the short-term (<7-day) safety and efficiency of electrical cardioversion for emergency department (ED) patients with atrial fibrillation or flutter have been established, the 30-day outcomes with respect to stroke, thromboembolic events, or death have not been investigated. Methods:, A two-center cohort of consecutive ED patients undergoing cardioversion for atrial fibrillation or flutter between January 1, 2000, and September 30, 2007, was retrospectively investigated. This cohort was probabilistically linked with both a regional ED database and the provincial health registry to determine which patients had a subsequent ED visit or hospital admission, stroke, or thromboembolic event or died within 30 days. In addition, trained reviewers performed a detailed chart abstraction on 150 randomly selected patients, with emphasis on demographics, vital signs, medical treatment, and predefined adverse events. Hemodynamically unstable patients or those whose condition was the result of an underlying acute medical diagnosis were excluded. Data were analyzed by descriptive methods. Results:, During the study period, 1,233 patients made 1,820 visits for atrial fibrillation or flutter to the ED. Of the 400 eligible patients undergoing direct-current cardioversion (DCCV), no patients died, had a stroke, or had a thromboembolic event in the following 30 days (95% confidence interval [CI] = 0.0 to 0.8% for all outcomes). A total of 141 patients were included in the formal chart review, with five patients (3.5%, 95% CI = 0.5% to 6.6%) failing cardioversion, six patients (4.3%, 95% CI = 0.9% to 7.6%) having a minor adverse event that did not change disposition, and five patients (3.5%, 95% CI = 0.5% to 6.6%) admitted to hospital at the index visit. Conclusions:, Cardioversion of patients with atrial fibrillation or flutter in the ED appears to have a very low rate of long-term complications. ACADEMIC EMERGENCY MEDICINE 2010; 17:408,415 2010 by the Society for Academic Emergency Medicine [source]

    Quality Indicators for the Care of Stroke and Atrial Fibrillation in Vulnerable Elders

    Eric M. Cheng MD
    First page of article [source]

    Anticoagulation to Prevent Strokes in Older People with Atrial Fibrillation: Assembling Individualized Risk and Benefit Information

    MRCP(UK), Richard Fuller MA
    No abstract is available for this article. [source]

    Temporary Epicardial Ventricular Stimulation in Patients with Atrial Fibrillation: Acute Effects of Ventricular Pacing Site on Bypass Graft Flows

    Navid Madershahian M.D.
    This study aimed to evaluate the optimal epicardial ventricular pacing site in patients with AF following coronary artery bypass surgery (CABG). Methods: In 23 consecutive patients (mean age = 69.2 1.9 years, gender = 62% male, ejection fraction [EF]= 50.4 2.1%) monoventricular stimulations (VVI) were tested with a constant pacing rate of 100 bpm. The impact of ventricular pacing on bypass graft flow (transit-time flow probe) and pulsatility index (PI) were measured after lead placement on the mid paraseptal region of the right (RVPS) and the left (LVPS) ventricle, on the right inferior wall (RVIW), and on the right ventricular outflow tract (RVOT). In addition, hemodynamic parameters were measured. Patients served as their own control. Results: Comparison of all tested pacing locations revealed that RVOT stimulation provided the highest bypass grafts flows (59.9 6.1 mL/min) and PI (2.2 0.1) when compared with RVPS (51.3 4.7 mL/min, PI = 2.6 0.2), RVIW (54.0 5.1 mL/m; PI = 2.4 0.2), and LVPS (53.1 4.5 mL/min; PI = 2.3 0.1), respectively (p < 0.05). When analyzing patients according to their preoperative LV function (group I = EF > 50%; group II = EF < 50%), higher bypass graft flows were observed with RVOT pacing in patients with lower EF (p = n.s.). Conclusions: Temporary RVOT pacing facilitates optimal bypass graft flows when compared with other ventricular pacing sites and should be the preferred method of temporary pacing in cardiac surgery patients with AF. Especially in patients with low EF following CABG, RVOT pacing may improve myocardial oxygen conditions for the ischemic myocardium and enhance graft patency in the early postoperative period. [source]

    Surgical Ablation of Atrial Fibrillation: The Columbia Presbyterian Experience

    Veli K. Topkara M.D.
    However, it is not widely applied due to its complexity, increased operative times, and the risk of bleeding. Various energy sources have been introduced to simplify the traditional "cut and sew" approach. Methods: This study involves patients undergoing surgical atrial fibrillation ablation (SAFA) at a single institution from 1999 to 2005. Type of concomitant procedures, preoperative clinical characteristics, and chronicity of AF were evaluated in overall patient population. Parameters including surgical approach, lesion pattern, and energy source used were collected intraoperatively. Clinical outcomes examined were postoperative rhythm success, stroke, early mortality, and long-term survival. Results: Three hundred thirty-nine patients were identified. Three hundred twenty-eight (96.8%) patients had associated cardiac disease and underwent concomitant procedures; 75.8% of patients had persistent AF. Energy sources used were microwave (49.8%), radiofrequency (42.2%), and laser (8.0%). In 41.9% of cases a pulmonary vein encircling lesion was the only lesion created. Combination lesion sets were performed in the remaining cases. Rhythm success rates at 3, 6, 12, and 24 months were 74.1%, 68.2%, 74.5%, and 71.1%, respectively. Patients who underwent surgical removal of left atrial appendage by means of stapling or simple excision had no early postoperative stroke. Early mortality was 4.9%. Postoperative survival rates at 1, 3, and 5 years were 89.6%, 83.1%, and 78.0%. Conclusions: Surgical ablation of atrial fibrillation is a safe and effective procedure in restoring sinus rhythm with excellent postoperative survival rates. Further advancements in the field will eventually result in minimally invasive procedures with higher success rates. [source]

    Atrial Remodeling After Mitral Valve Surgery in Patients with Permanent Atrial Fibrillation

    Fernando Hornero M.D., Ph.D.
    Mitral surgery allows an immediate surgical auricular remodeling and besides in those cases in which sinus rhythm is reached, it is followed by a late remodeling. The aim of this study is to investigate the process of postoperative auricular remodeling in patients with permanent atrial fibrillation undergoing mitral surgery. Methods: In a prospective randomized trial, 50 patients with permanent atrial fibrillation and dilated left atrium, submitted to surgical mitral repair, were divided into two groups: Group I contained 25 patients with left auricular reduction and mitral surgery, and Group II contained 25 patients with isolated valve surgery. Both groups were considered homogeneous in the preoperative assessment. Results: After a mean follow-up of 31 months, 46% of patients included in Group I versus 18% of patients included in Group II restarted sinus rhythm (p = 0.06). An auricular remodeling with size regression occurred in those patients who recovered from sinus rhythm, worthy of remark in Group II (,10.8% of left auricular volume reduction in Group I compared to ,21.5% in Group II; p < 0.05). A new atrial enlargement took place in those patients who remained with atrial fibrillation (+16.8% left auricular volume in Group I vs. +8.4% in Group II; p < 0.05). Conclusions: Mitral surgery produces an atrial postoperative volume that decrease especially when reduction techniques are employed. Late left atrial remodeling depended on the type of atrial rhythm and postoperative surgical volume. [source]

    Surgical Ablation of Permanent Atrial Fibrillation by Means of Maze Radiofrequency:

    Mid-Term Results
    We report our experience with a biatrial pattern of lesions based on the use of epicardial and endocardial radiofrequency ablation in an effort to minimize maze procedure. Method: In 85 patients undergoing cardiac surgery for established permanent atrial fibrillation (>3 months), a biauricular pattern of epicardic,endocardic maze lesions was performed. The main surgical procedures were diverse: 42 mitral valve surgeries, 7 mitrotricuspid valves, 18 mitroaortics, 4 mitroaortic and tricuspids, 2 aortic valves, 3 CABGs, 5 CABG and valve procedures, and 4 atrial septal defects. The mean age of the patients was 61 12 (range 39,78). The mean duration of atrial fibrillation was 5.8 years (range 0.3 to 24). Results: Sixty-two (72.9%) patients presented postoperative supraventricular arrhythmia. Hospital mortality was seen in five patients (5.8%). Two patients died after a 12-month mean follow-up (range 2 to 32). A total of 14.1% of patients remained with their previous atrial fibrillation and 85.9% recovered and maintained sinus rhythm, with two patients having a permanent pacemaker. A total of 56% patients have been followed-up for a period of more than 6 months, and among them prevalence of sinus rhythm is 87.5%. Echocardiography detected biauricular contraction in 65% of them. After analyzing the data, factors involved in postoperative recurrence of atrial fibrillation after radiofrequency surgery were oldness of the atrial fibrillation (p < 0.01) and pre and postoperative left auricle volume (p < 0.04). Conclusion: Intraoperative radiofrequency has permitted us to perform the maze procedure in a simple way, with a low surgical morbid-mortality. We have obtained an 85.9% electrographic effectiveness and a 65% recovery of atrial contraction. Postoperative incidence of arrhythmia is the main postoperative problem. [source]

    Percutaneous Catheter Ablation Procedures for the Treatment of Atrial Fibrillation

    Anthony R. Magnano M.D.
    Given the success of the surgical Maze procedure, initial catheter-based approaches involved creation of linear atrial lesions. Success rates were low and utility was limited by a high complication rate and long procedural times. The recent discovery that AF is often initiated by atrial ectopic beats has resulted in therapies designed to target the ectopic sources, particularly those within the pulmonary veins. Experience and technological advances have improved the efficacy and safety of such procedures. This article will review catheter ablation procedures for the maintenance of sinus rhythm in patients with AF. (J Card Surg 2004;19:188-195) [source]

    Predictors of Failure to Cure Atrial Fibrillation with the Mini-Maze Operation

    Zoltan A. Szalay M.D.
    A reduction in the number of right and left atrial incisions could decrease the operative time. The aim of this study was to assess the results of a mini-maze operation and to define predictors of its failure. Methods: Between 1995 and 2000, 72 patients (mean age 64 9 years) undergoing cardiac surgery had a concomitant mini-maze operation for symptomatic chronic atrial fibrillation. Three and 12 months postoperatively, heart rhythm and left atrial transport functions were assessed by electrophysiology, echocardiography, and magnetic resonance imaging. Multivariate analysis was performed to identify predictors of failure of the mini-maze operation. Results: Operative mortality was 1.4% (1/72). Death during follow-up occurred in 5.6% of patients (4/71), in one due to chronic heart failure. After 1 year, 80% of patients (48/60) were either in sinus rhythm (n = 43; 72%) or had a pacemaker (n = 5; 8%) implanted due to sick sinus syndrome. Intermittent and chronic atrial fibrillation was found in 20% of patients (12/60). Preoperative duration of atrial fibrillation (p = 0.05), preoperative left atrial diameter (p = 0.001), preoperative right atrial diameter (p = 0.02), a reduced left ventricular ejection fraction (p = 0.03), an increased left ventricular end-diastolic diameter (p = 0.04), and the presence of mitral valve stenosis (p = 0.001) were found to be univariate predictors of failure of the mini-maze operation 1 year postoperatively. Multivariate analysis defined preoperative diagnosis of mitral valve stenosis (p = 0.005; OR 117.5), longer duration of preoperative atrial fibrillation (p = 0.01; OR 1.33), and increased preoperative left ventricular end-systolic diameter (p = 0.02; OR 1.2) as incremental independent risk factors for failure of the mini-maze operation to cure chronic atrial fibrillation. Conclusion: The mini-maze operation is a safe procedure with similar results to that of Cox's Maze-III operation. The less-invasive mini-maze operation could be applicable even to patients with severely reduced left ventricular function, in whom complex cardiac surgery has to be performed concomitantly as well as in those presenting severe comorbidities. (J Card Surg 2004;19:1-6) [source]

    Persistence of Pulmonary Vein Isolation After Robotic Remote-Navigated Ablation for Atrial Fibrillation and its Relation to Clinical Outcome

    Robotic Remote Ablation for AF. Aims: A robotic navigation system (RNS, Hansen) has been developed as an alternative method of performing ablation for atrial fibrillation (AF). Despite the growing application of RNS-guided pulmonary vein isolation (PVI), its consequences and mechanisms of subsequent AF recurrences are unknown. We investigated the acute procedural success and persistence of PVI over time after robotic PVI and its relation to clinical outcome. Methods and Results: Sixty-four patients (60.7 9.8 years, 53 male) with paroxysmal AF underwent robotic circumferential PVI with 3-dimensional left atrial reconstruction (NavX). A voluntary repeat invasive electrophysiological study was performed 3 months after ablation irrespective of clinical course. Robotic PVI was successful in all patients without complication (fluoroscopy time: 23.5 [12,34], procedure time: 180 [150,225] minutes). Fluoroscopy time demonstrated a gradual decline but was significantly reduced after the 30th patient following the introduction of additional navigation software (34 [29,45] vs 12 [9,17] minutes; P < 0.001). A repeat study at 3 months was performed in 63% of patients and revealed electrical conduction recovery in 43% of all PVs. Restudied patients without AF recurrence (n = 28) showed a significantly lower number of recovered PVs (1 (0,2) vs 2 (2,3); P = 0.006) and a longer LA-PV conduction delay than patients with AF recurrences (n = 12). Persistent block of all PVs was associated with freedom from AF in all patients. At 3 months, 67% of patients were free of AF, while reablation of recovered PVs led to an overall freedom from AF in 81% of patients after 1 year. Conclusion: Robotic PVI for PAF is safe, effective, and requires limited fluoroscopy while yielding comparable success rates to conventional ablation approaches with PV reconduction as a common phenomenon associated with AF recurrences. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1079-1084) [source]

    Role of Residual Potentials Inside Circumferential Pulmonary Veins Ablation Lines in the Recurrence of Paroxysmal Atrial Fibrillation

    Residual Potentials After Pulmonary Vein Isolation. Background: Residual gaps due to incomplete ablation lines are known to be the most common cause of recurrent atrial fibrillation (AF) after catheter ablation. We hypothesized that any residual potentials at the junction of the left atrium and pulmonary vein (PV), inside the circumferential PV ablation (CPVA) lines, would contribute to the recurrence of AF or post-AF ablation atrial flutter (AFL); therefore, the elimination of these potentials increases AF-/AFL-free survival rates. Methods and Results: One hundred and two patients with paroxysmal AF (PAF) were enrolled and prospectively randomized to a group with ablation of residual potentials as add-on therapy to CPVA + PV electrical isolation (PVI) (group 1, n = 49), or a group without ablation of the residual potentials (group 2, n = 53). Post-CPVA residual potentials, inside the ablation lines, were identified by contact bipolar electrode mapping catheter and a detailed 3-dimensional voltage map. Twenty-three patients in group 1 and 18 patients in group 2 had post-CPVA residual potentials (46.9% vs 34.0%, P = 0.182). The AF-/AFL-free survival rate during follow-up of 23.3 7.9 months was not different in comparisons between the 2 groups (P = 0.818), and 79.6% and 81.1% of the patients in groups 1 and 2 maintained a sinus rhythm (P = 0.845), respectively. Conclusions: Residual potentials inside CPVA were commonly found in the patients with PAF after CPVA + PVI. Further ablation of residual potentials did not increase the efficacy of catheter ablation in patients with PAF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 959-965, September 2010) [source]

    The Impact of Age on the Electroanatomical Characteristics and Outcome of Catheter Ablation in Patients with Atrial Fibrillation

    Age and Atrial Fibrillation.,,Background: Previous studies have indicated that atrial fibrillation (AF) in patients over the age of 60 at diagnosis is a risk factor for a substantial increase in cardiovascular events. However, information about the impact of age on the atrial substrate and clinical outcome after catheter ablation of AF is limited. Methods: This study included 350 patients (53 12 years, 254 males) who underwent circumferential pulmonary vein isolation (CPVI) of AF, guided by a NavX mapping system. The subjects were divided into three groups according to their age, as follows: Group I: age ,50 (n = 141), Group II: age = 51,64 (n = 149) and Group III: age ,65 years old (n = 60). The mean voltage and total activation time of the individual atria were obtained by using a NavX mapping system before ablation. Several parameters, including the gender, AF duration, and left atrial (LA) diameter were analyzed. Results: The younger age group had a significantly smaller LA diameter (Group I vs Group II vs Group III, 36.89 7.11 vs 39.16 5.65 vs 40.77 4.95 mm, P = 0.002) and higher LA bipolar voltage (2.09 0.83 vs 1.73 0.73 vs 1.86 0.67 mV, respectively, P = 0.024), compared with the older AF patients. The LA bipolar voltage exhibited a significant reduction when the patients became older, however, that did not occur in the right atrium. The incidence of an AF recurrence was higher in the older age group than in the younger age groups. A subgroup of patients with lone AF was analyzed and age was found to be an independent predictor of the AF recurrence after receiving the first CPVI in the multivariable model (P < 0.05). Conclusions: Age has a significant impact on the LA substrate properties and outcome of the catheter ablation of AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 966-972, September 2010) [source]

    A Short-Term, Randomized, Double-Blind, Parallel-Group Study to Evaluate the Efficacy and Safety of Dronedarone versus Amiodarone in Patients with Persistent Atrial Fibrillation: The DIONYSOS Study

    Dronedarone versus Amiodarone in Patients with AF.,,Introduction: We compared the efficacy and safety of amiodarone and dronedarone in patients with persistent atrial fibrillation (AF). Methods: Five hundred and four amiodarone-nave patients were randomized to receive dronedarone 400 mg bid (n = 249) or amiodarone 600 mg qd for 28 days then 200 mg qd (n = 255) for at least 6 months. Primary composite endpoint was recurrence of AF (including unsuccessful electrical cardioversion, no spontaneous conversion and no electrical cardioversion) or premature study discontinuation. Main safety endpoint (MSE) was occurrence of thyroid-, hepatic-, pulmonary-, neurologic-, skin-, eye-, or gastrointestinal-specific events, or premature study drug discontinuation following an adverse event. Results: Median treatment duration was 7 months. The primary composite endpoint was 75.1 and 58.8% with dronedarone and amiodarone, respectively, at 12 months (hazard ratio [HR] 1.59; 95% confidence interval [CI] 1.28,1.98; P < 0.0001), mainly driven by AF recurrence with dronedarone compared with amiodarone (63.5 vs 42.0%). AF recurrence after successful cardioversion was 36.5 and 24.3% with dronedarone and amiodarone, respectively. Premature drug discontinuation tended to be less frequent with dronedarone (10.4 vs 13.3%). MSE was 39.3 and 44.5% with dronedarone and amiodarone, respectively, at 12 months (HR = 0.80; 95% CI 0.60,1.07; P = 0.129), and mainly driven by fewer thyroid, neurologic, skin, and ocular events in the dronedarone group. Conclusion: In this short-term study, dronedarone was less effective than amiodarone in decreasing AF recurrence, but had a better safety profile, specifically with regard to thyroid and neurologic events and a lack of interaction with oral anticoagulants. (J Cardiovasc Electrophysiol, Vol. 21, pp. 597-605, June 2010) [source]

    Ablation of Paroxysmal Atrial Fibrillation: Looking for the Simple Answer

    No abstract is available for this article. [source]

    Vagal Paroxysmal Atrial Fibrillation: Prevalence and Ablation Outcome in Patients Without Structural Heart Disease

    Prevalence of Vagal Paroxysmal Atrial Fibrillation.,Introduction: The prevalence of vagal and adrenergic atrial fibrillation (AF) and the success rate of pulmonary vein isolation (PVI) are not well defined. We investigated the prevalence of vagal and adrenergic AF and the ablation success rate of antral pulmonary vein isolation (APVI) in patients with these triggers compared with patients with random AF. Methods and Results: Two hundred and nine consecutive patients underwent APVI due to symptomatic drug refractory paroxysmal AF. Patients were diagnosed as vagal or adrenergic AF if >90% of AF episodes were related to vagal or adrenergic triggers; otherwise, a diagnosis of random AF was made. Clinical, electrocardiogram (ECG), and Holter follow-up was every 3 months in the first year and every 6 months afterward and for symptoms. Of 209 patients, 57 (27%) had vagal AF, 14 (7%) adrenergic AF, and 138 (66%) random AF. Vagal triggers were sleep (96.4%), postprandial (96.4%), late post-exercise (51%), cold stimulus (20%), coughing (7%), and swallowing (2%). At APVI, 94.3% of patients had isolation of all veins. Twenty-five (12%) patients had a second APVI. At a follow-up of 21 15 months, the percentage of patients free of AF was 75% in the vagal group, 86% in the adrenergic group, and 82% for random AF (P = 0.51). Conclusion: In patients with PAF and no structural heart disease referred for APVI, vagal AF is present in approximately one quarter. APVI is equally effective in patients with vagal AF as in adrenergic and random AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 489-493, May 2010) [source]

    ATP-Induced Dormant Pulmonary Veins Originating from the Carina Region After Circumferential Pulmonary Vein Isolation of Atrial Fibrillation

    Dormant Pulmonary Veins from the Carina Region.,Introduction: Elimination of transient pulmonary vein recurrences (dormant PVs) induced by an ATP injection and ablation at the PV carina region is an effective strategy for atrial fibrillation (AF) ablation. The relationship between dormant PVs and the PV carina region has not been evaluated. Methods: A total of 212 consecutive symptomatic AF patients underwent circumferential PV electrical isolation (CPVEI) with a double lasso technique. They were divided into 2 groups in a retrospective review; Group 1: those given an ATP injection during an intravenous isoproterenol infusion after the CPVEI (n = 106), and Group 2: those in which it was not given after the CPVEI (n = 106). Radiofrequency energy was applied at the earliest dormant PV activation site identified using a Lasso catheter on the CPVEI line and then PV carina region if it was ineffective. Results: After a successful PVEI, 54 patients (51%) in Group 1 had PV reconnections during an ATP injection. Acute PVEI sites were observed on the carina region within the CPVEI line in the right PVs (16%) and left PVs (10%). Dormant PVs were reisolated at the carina region in the right PVs (23%) and left PVs (26%). The distribution of the dormant PV sites, except for the RIPV, significantly differed from that of the acute PVEI sites (P < 0.05). Further, AF recurred significantly in the Group 2 patients as compared to those in Group 1 during 16 6.1 months of follow-up (P < 0.05). Conclusion: PV carina region origins may partly be responsible for an acute PVEI and potential recurrences. (J Cardiovasc Electrophysiol, Vol. 21, pp. 494-500, May 2010) [source]

    Endpoints in Ablation of Paroxysmal Atrial Fibrillation: When is Enough Enough?

    First page of article [source]

    Hybrid Therapy of Radiofrequency Catheter Ablation and Percutaneous Transvenous Mitral Commissurotomy in Patients With Atrial Fibrillation and Mitral Stenosis

    AF Ablation and PTMC.,Background: The rhythm control of atrial fibrillation (AF) associated with mitral stenosis (MS) is often difficult using antiarrhythmic drugs (AADs), even after a percutaneous transvenous mitral commissurotomy (PTMC). Few studies have examined the efficacy and safety of simultaneously performing radiofrequency catheter ablation (RFCA) and a PTMC in patients with MS and AF. Methods: Twenty consecutive patients with drug-resistant AF and rheumatic MS underwent RFCA combined with a PTMC (n = 10; persistent AF-8, long-lasting [>1 year] persistent AF-2; RFCA group) or transthoracic direct cardioversion (DC) following a PTMC (n = 10; persistent AF-7, long-lasting persistent AF-3; DC group). In all patients, the mitral valve morphology was amenable to a PTMC, and more than 2 AADs had been ineffective in maintaining sinus rhythm (SR). In the RFCA group, a segmental pulmonary vein isolation (PVI) was performed in the initial 5 patients, and an extensive PVI was performed in the remaining 5. Results: During a mean follow-up period of 4.0 2.7 years, 8 patients (80%) in the RFCA group were maintained in SR, as compared to 1 (10%) in the DC group (hazard ratio, 0.16; 95% confidence interval, 0.03 to 0.75; P = 0.008 by the log-rank test). The prevalence of the concomitant use of class I and/or class III AADs was comparable between the 2 groups (P = 0.70). No complications occurred during the procedure or follow-up period in either group. Conclusions: The hybrid therapy using RFCA and a PTMC was safe and feasible, and significantly improved the AF free survival rate compared to DC following a PTMC. (J Cardiovasc Electrophysiol, Vol. 21, pp. 284,289, March 2010) [source]

    Age-Related Increase in Atrial Fibrillation Induced by Transvenous Catheter-Based Atrial Burst Pacing: An In Vivo Rat Model of Inducible Atrial Fibrillation

    AF Rat Model Induced by Transvenous Catheter Pacing.,Introduction: Large animal models of atrial fibrillation (AF) are well established, but limited experimental reports exist on small animal models. We sought to develop an in vivo rat model of AF using a transvenous catheter and to evaluate the model's underlying characteristics. Methods and Results: Echocardiogram, surface electrocardiogram (ECG), and atrial effective refractory period (AERP) were recorded at baseline in young (3 months) and middle-aged (9 months) Wistar rats. AF inducibility and duration were measured through transvenous electrode catheter in young (n = 11) and middle-aged rats (n = 11) and middle-aged rats treated with either pilsicainide (1 mg/kg iv, n = 7) or amiodarone (10 mg/kg iv, n = 9). Degrees of interstitial fibrosis and cellular hypertrophy in the atria were assessed histologically. The P-wave duration and AERP were significantly longer and echocardiographic left atrial dimension significantly larger in middle-aged versus young rats. AF was inducible in >90% of all procedures in both untreated rat groups, whereas AF inducibility was reduced by the antiarrhythmic drugs. The AF duration was significantly longer in middle-aged than in young rats and was significantly shortened by treatment with either pilsicainide or amiodarone. Histologic analysis revealed significant increases in atrial interstitial fibrosis and cellular diameter in middle-aged versus young rats. Conclusions: Transvenous catheter-based AF is significantly longer in middle-aged than in young rats and is markedly reduced by treatment with antiarrhythmic drugs. This rat model of AF is simple, reproducible, and reliable for examining pharmacologic effects on AF and studying the process of atrial remodeling.(J Cardiovasc Electrophysiol, Vol. 21, pp. 88,93, January 2010) [source]

    The Relationship Between Endocardial Voltage and Regional Volume in Electroanatomical Remodeled Left Atria in Patients with Atrial Fibrillation: Comparison of Three-Dimensional Computed Tomographic Images and Voltage Mapping

    Background: Long-standing atrial fibrillation (AF) changes left atrial (LA) morphology, and the LA size is related to recurrence after radiofrequency catheter ablation (RFCA). We hypothesize that LA morphology, based on embryological origin, affects the outcome of RFCA. Methods: We analyzed 3D computed tomographic (CT) images of LA in 70 patients with AF (54 males, 55.6 10.5 years old, paroxysmal AF (PAF):persistent AF (PeAF) = 32:38) who underwent RFCA. Each LA image was divided into venous atrium (VA), anterior LA (ALA), LA appendage (LAA), and both antrum. Absolute and relative volumes were calculated, and the lengths of linear ablation sites were measured. Results: (1) In patients with the mean LA voltage , 2.0 mV, LA volume, especially ALA, was larger (P < 0.01) compared to those with LA voltage > 2.0 mV. (2) The total LA volume was significantly larger (P < 0.01) and LAA voltages (P < 0.05) and conduction velocities (P < 0.05) were lower in patients with PeAF than in those with PAF. (3) In patients with recurrence, LA volume was generally larger (P < 0.01) than in those without recurrence. In PAF patients with recurrence, the relative volume of ALA was significantly larger (P < 0.01) than those without recurrence. Conclusions Morphologically remodeled LA has low endocardial voltage, and enlargement of ALA is more significant in electroanatomically remodeled LA. The disproportional enlargement of ALA was observed more often in PAF patients with recurrence after ablation than those without recurrence. [source]

    Incidence and Predictors of Periprocedural Cerebrovascular Accident in Patients Undergoing Catheter Ablation of Atrial Fibrillation

    Background: Cerebrovascular accident (CVA) is a serious complication of catheter ablation of atrial fibrillation (AF). The incidence and clinical predictors of periprocedural CVA in patients undergoing AF ablation are not fully understood. Methods: This study included 721 cases (age 57 11 years; 23% female; 345 persistent AF) in 579 consecutive patients referred for AF ablation. Periprocedural CVA was defined as onset of a new neurologic deficit that occurred anytime between the start of the procedure and 30 days after the AF ablation, and was confirmed by a neurologist. Cranial imaging with CT and/or MRI was performed in each case. Patients were anticoagulated with warfarin for at least 4 weeks pre- and immediately postprocedure and were bridged with enoxaparin. Transesophageal echocardiography was performed within 24 hours prior to ablation in all cases. Results: Periprocedural CVA occurred in 10 of 721 cases (1.4%). The risk of periprocedural CVA did not vary significantly during the course of the study. Among these 10 patients (age 62 11 years; 1 female; 5 persistent AF), 6 manifested neurological deficits within 24 hours, 3 after 24,48 hours, and 1 patient had a CVA 6 days following AF ablation despite a therapeutic INR level. All CVAs were ischemic. Five patients had residual deficits after 30 days. Four of 43 patients (9.3%) with a prior history of CVA had periprocedural CVA. Periprocedural CVA occurred in 0.3%, 1.0%, and 4.7% of patients with CHADS2 scores of 0, 1, and , 2 (P < 0.001). In 2 separate multivariate analyses, a CHADS2 score , 2 (OR 7.1, P = 0.02) and history of CVA (OR 9.5, P < 0.01) remained independent predictors of periprocedural CVA. Conclusions: Despite periprocedural anticoagulation and transesophageal echocardiography, we found a 1.4% incidence of periprocedural CVA in AF ablation patients. A CHADS2 score , 2 and a history of CVA are independent predictors of CVA after AF ablation. The CVA risk is low in patients with CHADS2 score of 0. [source]