Disparate activation of the coronary sinus and inferior left atrium during atrial tachycardia after persistent atrial fibrillation ablation: prevalence, pitfalls, and impact on mapping

Persistent atrial fibrillation (AF) ablation may lead to partial disconnection of the coronary sinus (CS). As a result, disparate activation sequences of the local CS versus contiguous left atrium (LA) may be observed during atrial tachycardia (AT). We aimed to evaluate the prevalence of this phenomenon and its impact on activation mapping.

Current hot potatoes in atrial fibrillation ablation

Atrial fibrillation (AF) ablation has evolved to the treatment of choice for patients with drug-resistant and symptomatic AF. Pulmonary vein isolation at the ostial or antral level usually is sufficient for treatment of true paroxysmal AF. For persistent AF ablation, drivers and perpetuators outside of the pulmonary veins are responsible for AF maintenance and have to be targeted to achieve satisfying arrhythmia-free success rate. Both complex fractionated atrial electrogram (CFAE) ablation and linear ablation are added to pulmonary vein isolation for persistent AF ablation. Nevertheless, ablation failure and necessity of repeat ablations are still frequent, especially after persistent AF ablation. Pulmonary vein reconduction is the main reason for arrhythmia recurrence after paroxysmal and to a lesser extent after persistent AF ablation. Failure of persistent AF ablation mostly is a consequence of inadequate trigger ablation, substrate modification or incompletely ablated or reconducting linear lesions. In this review we will discuss these points responsible for AF recurrence after ablation and review current possibilities on how to overcome these limitations.

Pattern and timing of the coronary sinus activation to guide rapid diagnosis of atrial tachycardia after atrial fibrillation ablation

BACKGROUND Atrial tachycardias (AT) during or after ablation of atrial fibrillation frequently pose a diagnostic challenge. We hypothesized that both the patterns and the timing of coronary sinus (CS) activation could facilitate AT mapping. METHODS AND RESULTS A total of 140 consecutive postpersistent atrial fibrillation ablation patients with sustained AT were investigated by conventional mapping. CS activation pattern was defined as chevron or reverse chevron when the activations recorded on both the proximal and the distal CS dipoles were latest or earliest, respectively. The local activation of mid-CS was timed with reference to Ppeak-Ppeak (P-P) interval in lead V1. A ratio, mid-CS activation time to AT cycle length, was computed. Of 223 diagnosed ATs, 124 were macroreentrant (56%) and 99 were centrifugal (44%). When CS activation was chevron/reverse chevron (n=44; 20%), macroreentries were mostly roof dependent. With reference to P-P interval, mid-CS activation timing showed specific consistency for peritricuspid and perimitral AT. Proximal to distal CS activation pattern and mid-CS activation at 50% to 70% of the P-P interval (n=30; 13%) diagnosed peritricuspid AT with 81% sensitivity and 89% specificity. Distal to proximal CS activation and mid-CS activation at 10% to 40% of the P-P interval (n=44; 20%) diagnosed perimitral AT with 88% sensitivity and 75% specificity. CONCLUSIONS The analysis of the patterns and timing of CS activation provides a rapid stratification of most likely macroreentrant ATs and points toward the likely origin of centrifugal ATs. It can be included in a stepwise diagnostic approach to rapidly select the most critical mapping maneuvers.

Pulmonary veins to left atrium cycle length gradient predicts procedural and clinical outcomes of persistent atrial fibrillation ablation.

BACKGROUND Rapid pulmonary vein (PV) activity has been shown to maintain paroxysmal atrial fibrillation (AF). We evaluated in persistent AF the cycle length (CL) gradient between PVs and the left atrium (LA) in an attempt to identify the subset of patients where PVs play an important role. METHODS AND RESULTS Ninety-seven consecutive patients undergoing first ablation for persistent AF were studied. For each PV, the CL of the fastest activation was assessed over 1 minute (PVfast) using Lasso recordings. The PV to LA CL gradient was quantified by the ratio of PVfast to LA appendage (LAA) AF CL. Stepwise ablation terminated AF in 73 patients (75%). In the AF termination group, the PVfast CL was much shorter than the LAA CL resulting in lower PVfast/LAA ratios compared with the nontermination group (71±10% versus 92±7%; P<0.001). Within the termination group, PVfast/LAA ratios were notably lower if AF terminated after PV isolation or limited adjunctive substrate ablation compared with patients who required moderate or extensive ablation (63±6% versus 75±8%; P<0.001). PVfast/LAA ratio <69% predicted AF termination after PV isolation or limited substrate ablation with 74% positive predictive value and 95% negative predictive value. After a mean follow-up of 29±17 months, freedom from arrhythmia recurrence off-antiarrhythmic drugs was achieved in most patients with PVfast/LAA ratios <69% as opposed to the remaining population (80% versus 43%; P<0.001). CONCLUSIONS The PV to LA CL gradient may identify the subset of patients in whom persistent AF is likely to terminate after PV isolation or limited substrate ablation and better long-term outcomes are achieved.

Topographic variability of the esophageal left atrial relation influencing ablation lines in patients with atrial fibrillation.

UNLABELLED Topography of the esophagus in atrial fibrillation ablation. INTRODUCTION The close anatomic relationship of the posterior wall of the left atrium (LA) and the thermosensitive esophagus creates a potential hazard in catheter ablation procedures. METHODS AND RESULTS In 30 patients (pts) with atrial fibrillation (AF) undergoing catheter ablation, we prospectively studied the course and contact of the esophagus in relation to LA and the topographic proximity to ablation lines encircling the right-sided and left-sided pulmonary veins (PV) as well as to the posterior line connecting the encircling lines using the electromagnetic mapping system for reconstruction of LA and for tagging of the esophagus. This new technique of anatomic tagging of the esophagus was validated against the CT scan as a standard imaging procedure. The esophageal course was highly variable, extending from courses in direct vicinity to the left- or right-sided PV as well as in the midportion of the posterior LA. In order to avoid energy application in direct proximity to the esophagus, adjustments of the left and right PV encircling lines were necessary in 14/30 pts (47%) and 3/30 (10%). In 30 pts (100%), the mid- to inferior areas of the posterior LA revealed contact with the esophagus. Therefore, posterior and inferior linear ablation lines were abandoned and shifted to superior in 29 pts (97%). CONCLUSIONS Anatomic tagging of esophagus revealed a highly variable proximity to different areas of the posterior LA suggesting individual adjustment of encircling and linear ablation lines in AF ablation procedures to avoid the life threatening complication of esophagus perforation.

Mapping of atrial tachycardias after catheter ablation for atrial fibrillation: use of bi-atrial activation patterns to facilitate recognition of origin

Mapping and ablation of atrial tachycardias (ATs) secondary to catheter ablation of atrial fibrillation (AF) is often challenging due to the complex atrial substrate, different AT mechanisms, and potential origin not only in the left atrium (LA) but also from the right atrium (RA) and the adjacent thoracic veins.

Catheter ablation of atrial fibrillation as first-line therapy--a single-centre experience

The aims of the study were (i) to assess the characteristics of patients selected for atrial fibrillation (AF) ablation as first-line therapy, (ii) to identify current clinical criteria for such a strategy, and (iii) to analyse the outcome compared with patients who had failure of antiarrhythmic drug (AAD) therapy prior to ablation.

Electroanatomic reconstruction of the left atrium, pulmonary veins, and esophagus compared with the "true anatomy" on multislice computed tomography in patients undergoing catheter ablation of atrial fibrillation

BACKGROUND: Current concepts of catheter ablation for atrial fibrillation (AF) commonly use three-dimensional (3D) reconstructions of the left atrium (LA) for orientation, catheter navigation, and ablation line placement. OBJECTIVES: The purpose of this study was to compare the 3D electroanatomic reconstruction (Carto) of the LA, pulmonary veins (PVs), and esophagus with the true anatomy displayed on multislice computed tomography (CT). METHODS: In this prospective study, 100 patients undergoing AF catheter ablation underwent contrast-enhanced spiral CT scan with barium swallow and subsequent multiplanar and 3D reconstructions. Using Carto, circumferential plus linear LA lesions were placed. The esophagus was tagged and integrated into the Carto map. RESULTS: Compared with the true anatomy on CT, the electroanatomic reconstruction accurately displayed the true distance between the lower PVs; the distances between left upper PV, left lower PV, right lower PV, and center of the esophagus; the longitudinal diameter of the encircling line around the funnel of the left PVs; and the length of the mitral isthmus line. Only the distances between the upper PVs, the distance between the right upper PV and esophagus, and the diameter of the right encircling line were significantly shorter on the electroanatomic reconstructions. Furthermore, electroanatomic tagging of the esophagus reliably visualized the true anatomic relationship to the LA. On multiple tagging and repeated CT scans, the LA and esophagus showed a stable anatomic relationship, without relevant sideward shifting of the esophagus. CONCLUSION: Electroanatomic reconstruction can display with high accuracy the true 3D anatomy of the LA and PVs in most of the regions of interest for AF catheter ablation. In addition, Carto was able to visualize the true anatomic relationship between the esophagus and LA. Both structures showed a stable anatomic relationship on Carto and CT without relevant sideward shifting of the esophagus.

Transseptal puncture for catheter ablation of atrial fibrillation after device closure of patent foramen ovale

The technique of transseptal puncture for catheter ablation of atrial fibrillation after percutaneous closure of a foramen ovale with the Amplatzer Occluder is demonstrated based on 2 representative cases.

Esophagus imaging for catheter ablation of atrial fibrillation: comparison of two methods with showing of esophageal movement

This study aims to evaluate whether visualization and integration of the computed tomography (CT) scan of the left atrium (LA) and the esophagus into the three-dimensional (3D) electroanatomical map the day before ablation is accurate compared with integration of an esophagus tag into the electroanatomic LA map visualizing the anatomic relationship during the radiofrequency ablation or whether esophagus movement prohibits esophagus visualization the day before ablation.

Effects of Gender on the Incidence of Cardiac Tamponade Following Catheter Ablation of Atrial Fibrillation: Results from a Worldwide Survey in 34,943 AF Ablation Procedures.

BACKGROUND -Cardiac tamponade is the most dramatic complication observed during atrial fibrillation (AF) ablation and the leading cause of procedure-related mortality. Female gender is a known risk factor for complications during AF ablation; however, it is unknown whether women have a higher risk of tamponade. METHODS AND RESULTS -A systematic Medline search was used to locate academic electrophysiologic (EP) centers that reported cases of tamponade occurring during AF ablation. Centers were asked to provide information on cases of acute tamponade according to gender and their mode of management including any case of related mortality. Nineteen EP centers provided information on 34,943 ablation procedures involving 25,261 (72%) males. Overall 289 (0.9%) cases of tamponade were reported: 120 (1.24%) in females and 169 (0.67%) in males (odds ratio 1.83, P<0.001). There was a reciprocal association between center volume and the occurrence of tamponade with substantial lower risk in high volume centers. Most cases of tamponade occurred during catheter manipulation or ablation; females tended to develop more tamponades during transseptal catheterization. No gender difference in the mode of management was observed. However, 16% cases of tamponade required surgery with lower rates in high volume centers. Three cases of tamponade (1%) culminated in death. CONCLUSIONS -Tamponade during AF ablation procedures is relatively rare. Women have an almost twofold higher risk for developing this complication. The risk of tamponade among women decreases substantially in high volume centers. Surgical back-up and acute management skills for treating tamponade are important in centers performing AF ablation.

Value of different follow-up strategies to assess the efficacy of circumferential pulmonary vein ablation for the curative treatment of atrial fibrillation.

BACKGROUND The objective of this study was to compare transtelephonic ECG every 2 days and serial 7-day Holter as two methods of follow-up after atrial fibrillation (AF) catheter ablation for the judgment of ablation success. Patients with highly symptomatic AF are increasingly treated with catheter ablation. Several methods of follow-up have been described, and judgment on ablation success often relies on patients' symptoms. However, the optimal follow-up strategy objectively detecting most of the AF recurrences is yet unclear. METHODS Thirty patients with highly symptomatic AF were selected for circumferential pulmonary vein ablation. During follow-up, a transtelephonic ECG was transmitted once every 2 days for half a year. Additionally, a 7-day Holter was recorded preablation, after ablation, after 3 and 6 months, respectively. With both, procedures symptoms and actual rhythm were correlated thoroughly. RESULTS A total of 2,600 transtelephonic ECGs were collected with 216 of them showing AF. 25% of those episodes were asymptomatic. On a Kaplan-Meier analysis 45% of the patients with paroxysmal AF were still in continuous SR after 6 months. Simulating a follow-up based on symptomatic recurrences only, that number would have increased to 70%. Using serial 7-day ECG, 113 Holter with over 18,900 hours of ECG recording were acquired. After 6 months the percentage of patients classified as free from AF was 50%. Of the patients with recurrences, 30-40% were completely asymptomatic. The percentage of asymptomatic AF episodes stepwise increased from 11% prior ablation to 53% 6 months after. CONCLUSIONS The success rate in terms of freedom from AF was 70% on a symptom-only-based follow-up; using serial 7-day Holter it decreased to 50% and on transtelephonic monitoring to 45%, respectively. Transtelephonic ECG and serial 7-day Holter were equally effective to objectively determine long-term success and to detect asymptomatic patients.