Imke Drewitz

Long-term single- and multiple-procedure outcome and predictors of success after catheter ablation for persistent atrial fibrillation

BACKGROUND Stepwise ablation is an effective treatment for persistent atrial fibrillation (AF), although it often requires multiple procedures to eliminate recurrent arrhythmias. OBJECTIVE This study evaluated single- and multiple-procedure long-term success rates and potential predictors of a favorable single-procedure outcome of stepwise ablation for persistent AF. METHODS This study comprised 395 patients with persistent AF (duration 16 months) undergoing de novo catheter ablation using the stepwise approach. Procedural success was defined as the absence of any arrhythmia recurrence. Patient characteristics and electrophysiological parameters were analyzed with respect to single- and multiple-procedure outcomes. RESULTS After a follow-up of 27 ± 7 months, 108 (27%) patients were free of arrhythmia recurrences with a single procedure. After 2.3 ± 0.6 procedures, 312 (79%) patients were free of arrhythmia with concomitant antiarrhythmic treatment in 38% (23% on β-blocker). Female gender, duration of persistent AF, and congestive heart failure were predictive for the outcome after first ablation. However, the strongest predictors for single-procedure success were longer baseline AF cycle length (CL) and procedural AF termination. Moreover, procedural AF termination during the index procedure also predicted a favorable outcome after the last procedure, while the existence of congestive heart failure was associated with an increased risk for eventual arrhythmia recurrences. CONCLUSIONS Single-procedure long-term success is anticipated in approximately a quarter of patients undergoing de novo ablation of persistent AF. Baseline AFCL emerged as the strongest predictor of single-procedure success, while AF termination during index ablation predicts the overall outcome. However, an overall success rate of 79% is achievable with multiple procedures.

Chronic atrial fibrillation is a biatrial arrhythmia: data from catheter ablation of chronic atrial fibrillation aiming arrhythmia termination using a sequential ablation approach.

Background— Termination of chronic atrial fibrillation (CAF) can be achieved by catheter ablation using a stepwise approach. However, there are limited data on the contribution of the right atrium to the CAF process. Furthermore, the prognostic value of CAF termination remains unclear. Methods and Results— Eighty-eight patients (61±10 years of age) underwent de novo ablation of CAF in 2006 at our institution. The ablation procedure was performed sequentially in the following order: pulmonary vein isolation, defragmentation of the left atrium, coronary sinus, and right atrium. Attempted procedural end point was termination of CAF. Consecutive arrhythmias occurring after AF termination were mapped, and ablation was attempted. AF termination was achieved in 68 (77%) patients: in 37 (55%) patients it occurred in the left atrium, in 18 (26%) patients in the right atrium, and in 13 (19%) patients in the coronary sinus. In 54 patients, at least one redo was performed (total number of procedures: 154). After the first redo, another 30 patients were in sinus rhythm (total 63), 8 patients were in atrial tachycardia (AT), and 17 patients were in AF. Another 11 patients underwent a second redo. After a mean follow-up of 20±4 months, 71 (81%) patients were in sinus rhythm, 1 (1%) patient was in AT, and 16 (18%) patients were in AF. Patients with CAF termination had predominantly ATs as recurrent arrhythmias (83%), whereas those without mainly presented with recurrent CAF (85%). The overall success rate in patients with CAF termination was 95% compared with 5% of patients without CAF termination in 2 procedures (n=12). In almost all redo procedures attributable to AT, at least 1 AT during redo was documented previously. Conclusions— AF termination is a prognostic important end point of catheter ablation for CAF. Termination of AF was achieved in both atria and the coronary sinus, suggesting a biatrial substrate of CAF. Subsequent arrhythmias often recur during follow-up and, therefore, should be targeted for ablation. Received February 11, 2008; accepted September 15, 2008. # CLINICAL PERSPECTIVE {#article-title-2}Background—Termination of chronic atrial fibrillation (CAF) can be achieved by catheter ablation using a stepwise approach. However, there are limited data on the contribution of the right atrium to the CAF process. Furthermore, the prognostic value of CAF termination remains unclear. Methods and Results—Eighty-eight patients (61±10 years of age) underwent de novo ablation of CAF in 2006 at our institution. The ablation procedure was performed sequentially in the following order: pulmonary vein isolation, defragmentation of the left atrium, coronary sinus, and right atrium. Attempted procedural end point was termination of CAF. Consecutive arrhythmias occurring after AF termination were mapped, and ablation was attempted. AF termination was achieved in 68 (77%) patients: in 37 (55%) patients it occurred in the left atrium, in 18 (26%) patients in the right atrium, and in 13 (19%) patients in the coronary sinus. In 54 patients, at least one redo was performed (total number of procedures: 154). After the first redo, another 30 patients were in sinus rhythm (total 63), 8 patients were in atrial tachycardia (AT), and 17 patients were in AF. Another 11 patients underwent a second redo. After a mean follow-up of 20±4 months, 71 (81%) patients were in sinus rhythm, 1 (1%) patient was in AT, and 16 (18%) patients were in AF. Patients with CAF termination had predominantly ATs as recurrent arrhythmias (83%), whereas those without mainly presented with recurrent CAF (85%). The overall success rate in patients with CAF termination was 95% compared with 5% of patients without CAF termination in 2 procedures (n=12). In almost all redo procedures attributable to AT, at least 1 AT during redo was documented previously. Conclusions—AF termination is a prognostic important end point of catheter ablation for CAF. Termination of AF was achieved in both atria and the coronary sinus, suggesting a biatrial substrate of CAF. Subsequent arrhythmias often recur during follow-up and, therefore, should be targeted for ablation.

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.

Reduced fluoroscopy during atrial fibrillation ablation: benefits of robotic guided navigation.

Reduced Fluoroscopy in PVI Using RN. Background: Recently, a nonmagnetic robotic navigation system (RN, Hansen‐Sensei™) has been introduced for remote catheter manipulation.

Catheter ablation of paroxysmal atrial fibrillation improves cardiac function: a prospective study on the impact of atrial fibrillation ablation on left ventricular function assessed by magnetic resonance imaging

AIMS Beneficial effects of atrial fibrillation (AF) ablation have been demonstrated in patients with congestive heart failure (CHF) and significantly impaired left ventricular ejection fraction (LVEF). However, the impact of pulmonary vein isolation (PVI) on cardiac function in patients with paroxysmal AF and impaired LVEF remains under discussion. This study aimed to evaluate the impact of PVI for paroxysmal AF on cardiac function in patients with impaired LVEF using cardiac magnetic resonance imaging (CMRI). METHODS AND RESULTS A total number of 70 patients with paroxysmal AF and episodes < or = 24 h were scanned on a 1.5-T-CMRI before and 6 months after PVI during sinus rhythm. End-diastolic volume, end-systolic volume, and LVEF were determined by epicardial and endocardial measurements. Patients were categorized into two groups regarding cardiac function as assessed by CMRI: group 1 patients (n = 18) with an LVEF < 50% and patients with an LVEF > 50% (group 2, n = 52). Group 1 patients demonstrated a significant lower success rate than patients of group 2 after a follow-up of 152 +/- 40 days (50 vs. 73%, P < 0.05). Cardiac magnetic resonance imaging in group 1 patients demonstrated a significant improvement in cardiac function after AF ablation (41 +/- 6 vs. 51 +/- 12%, P = 0.004), whereas group 2 patients did not show significant differences (60 +/- 6 vs. 59 +/- 9%, P = 0.22) after a 6 months follow-up. CONCLUSION Pulmonary vein isolation improves cardiac function in patients with paroxysmal AF and impaired LVEF. These data suggest that an impaired LV function can be partially attributed to AF with short-lasting paroxysms.

Characterization, Mapping, and Catheter Ablation of Recurrent Atrial Tachycardias After Stepwise Ablation of Long-Lasting Persistent Atrial Fibrillation

Background—Atrial tachycardias (AT) often occur after ablation of long-lasting persistent AF (CAF) and are difficult to treat conservatively. This study evaluated mechanisms and success rates of conventional mapping and catheter ablation of recurrent ATs occurring late after stepwise ablation of CAF. Methods and Results—A total of 320 patients underwent de novo ablation of CAF using a stepwise ablation approach in 2006 to 2007 at our institution. This study comprised patients who presented with recurrent ATs at their first redo procedure after initial de novo CAF ablation. All procedures were guided by conventional mapping techniques exclusively. Sixty-one patients (63±10 years, 14 women) presented with their clinical AT at their redo procedure 7.7±4.4 months after initial de novo CAF ablation. A total of 133 ATs (2.2±0.9 per patient) were mapped. Forty-four (72%) were due to reentry; 17 (28%) were focal ATs. Reentry ATs were mainly characterized as roof and perimitral flutter (43% and 34%, respectively). Focal ATs mainly originated from the great thoracic veins (pulmonary veins: 41%, coronary sinus: 23%). Forty-five (74%) patients had conduction recovery of at least 1 pulmonary vein (mean, 1.2±0.8). Overall, 124 (93%) ATs could be ablated successfully. The mean procedure duration was 181±59 minutes, with a mean fluoroscopy time of 45±21 minutes. After a mean follow-up of 21±4 months, 50 (82%) patients were free of any arrhythmia recurrences after a single redo procedure. Conclusions—Although late recurrent ATs may have complex mechanisms, catheter ablation guided exclusively by conventional techniques is highly effective with excellent acute and long-term success rates.

Interactive real-time mapping and catheter ablation of the cavotricuspid isthmus guided by magnetic resonance imaging in a porcine model

Aims We investigated the feasibility of real-time magnetic resonance imaging (RTMRI) guided ablation of the cavotricuspid isthmus (CTI) by using a MRI-compatible ablation catheter. Methods and results Cavotricuspid isthmus ablation was performed in an interventional RTMRI suite by using a novel 7 French, steerable, non-ferromagnetic ablation catheter in a porcine in vivo model (n = 20). The catheter was introduced and navigated by RTMRI visualization only. Catheter position and movement during manipulation were continuously visualized during the entire intervention. Two porcine prematurely died due to VT/VF. Anatomical completion of the CTI ablation line could be achieved after a mean of 6.3±3 RF pulses (RF energy: 1807±1016.4 Ws/RF pulse, temperature: 55.9±5.9°C) in n = 18 animals. In 15 of 18 procedures (83.3%) a complete CTI block was proven by conventional mapping in the electrophysiological (EP) lab. Conclusion Completely non-fluoroscopic ablation guided by RTMRI using a steerable and non-ferromagnetic catheter is a promising novel technology in interventional electrophysiology.

Propofol sedation administered by cardiologists without assisted ventilation for long cardiac interventions: an assessment of 1000 consecutive patients undergoing atrial fibrillation ablation

AIMS Patients can expect a cure from atrial fibrillation (AF) with ablation. Procedural safety and success depend on patient comfort, compliance, and immobility. This is difficult to achieve with benzodiazepine and opiate boluses that are the mainstay of current practice. We sought to determine the safety and efficacy of propofol infusion sedation administered to patients without assisted ventilation for AF ablation. METHODS AND RESULTS Procedural data from 1000 consecutive patients undergoing AF ablation were analysed. Sedation with 2% propofol was used in all procedures without assisted ventilation and was administered, monitored, and controlled by electrophysiologists. Primary outcome measures were adverse sedative affects including (i) respiratory depression (SpO(2)< 90% for >20 s) and (ii) persistent hypotension [systolic blood pressure (SBP)<90 mmHg at minimum sedation level]. Secondary endpoints included full recovery within 60 min and procedural complications. Of 1000 ablations, 506 ablations were performed for persistent and 494 for paroxysmal AF. Average patient age was 60.1 ± 11.3 years (72.3% male). Propofol was commenced in all patients at a mean infusion rate of 18.5 ± 4.8 mL/h with a mean baseline SBP of 140.3 ± 19.9 mmHg. Mean procedure time was 148.7 ± 57.7 min. Adverse sedative effects necessitating cessation of propofol and switch to midazolam bolus sedation occurred in 15.6% of patients (13.6% due to persistent hypotension, 1.9% due to respiratory depression, and 0.1% due to hypersalivation). Patients who had persistent hypotension were older (62.9 ± 11.2 vs. 60.0 ± 11.4 years, P= 0.011) and more likely to be female (39.5 vs. 23.7%, P< 0.001) than those who tolerated propofol. Patient age correlated to maximum blood pressure drop with propofol (R(2)= 0.101, P< 0.001) and inversely correlated to mean propofol infusion rate (R(2)= 0.066, P< 0.001). No procedures were abandoned due to adverse effects of sedation. All patients recovered within 60 min. Serious procedural complications, unrelated to sedation, occurred in 0.5%, all of whom had pericardial tamponade successfully treated with percutaneous pericardiocentesis. CONCLUSIONS Sedation with 2% propofol infusion administered by cardiologists without assisted ventilation is safe, effective, and practical for use in AF ablation without serious or residual complications. In this setting, persistent hypotension is the most common acute adverse effect requiring cessation of propofol in ∼14%.

Robotic versus conventional ablation for common-type atrial flutter: A prospective randomized trial to evaluate the effectiveness of remote catheter navigation

BACKGROUND Conventional catheter ablation for common-type atrial flutter (AFL) is a widely established therapy but has not been compared with the use of a robotic navigation system (RNS) thus far. OBJECTIVES The purpose of this study was to investigate the feasibility of a new, nonmagnetic RNS with regard to safety, efficacy, and X-ray exposure to investigator and patient compared with the conventional ablation approach in patients with AFL. METHODS Fifty patients (65.7 +/- 9.3 years, 40 male) undergoing de novo catheter ablation for AFL were randomly assigned to conventional or RNS-guided cavotricuspid isthmus (CTI) ablation. RESULTS Complete bidirectional isthmus block was achieved for all patients without occurrence of procedure-related complications. The fluoroscopy time and the investigator X-ray exposure (8.2 +/- 4.6 vs. 5.8 +/- 3.6, P = .038; and 8.2 +/- 4.6 vs. 1.9 +/- 1.1 minutes, P<.001) as well as the mean radiofrequency (RF) duration and the energy delivered were significantly higher in the conventional than in the RNS group (321.7 +/- 214.6 vs. 496.4 +/- 213.9 seconds, P = .006; 8279 +/- 5767 vs. 16,308 +/- 6870 J, P<.001, respectively). The overall procedure time in the RNS group was significantly longer than in the conventional group (79.2 +/- 30.6 vs. 58.4 +/- 17.7 minutes; P = .04) but significantly decreased comparing the first 10 with the last 10 patients in the RNS group (105.3 +/- 34.8 vs. 60.6 +/- 6.3 minutes; P = .003). Starting ablation during AFL, bidirectional block instantly after termination was observed in 90% of the RNS and 50% of the conventionally treated patients (P = .03). CONCLUSION The present study demonstrates the safety and feasibility of RNS for performing CTI ablation in patients with common-type AFL for use in the clinical routine. As a result of the remote navigation, X-ray exposure and RF duration to achieve bidirectional block were significantly decreased and occurred more often immediately after AFL termination. These findings are consistent with increased catheter stability and RF application efficacy using RNS compared with conventional catheter manipulation.

Prospective, multicentre validation of a simple, patient-operated electrocardiographic system for the detection of arrhythmias and electrocardiographic changes

AIMS Electrocardiographic changes, e.g. arrhythmias causing syncope or palpitations, are often transient and therefore difficult to diagnose. Systematic and symptom-activated ECG recordings can increase diagnostic yield in such patients. We evaluated the diagnostic accuracy of a simple, leadless, patient-operated ECG device compared with a standard 12-lead ECG. METHODS AND RESULTS We recorded a standard 12-lead surface ECG and a patient-activated ECG in direct succession in 508 consecutive patients enrolled in four centres. All ECGs were analysed by a single, blinded observer. ECGs were analysable in 505 (99.4%) patients (66% male, age 61 +/- 15 years, and body mass index 27 +/- 4). Analysis of the patient-activated ECG adequately detected a normal ECG (sensitivity 91% and specificity 95%), atrial fibrillation (AF) (sensitivity 99% and specificity 96%), and even T-wave abnormalities (sensitivity 90% and specificity 75%). Diagnostic accuracy for atrioventricular nodal block was moderate (sensitivity 79% and specificity 99%). Continuous parameters correlated well: (r(2) = 0.89 for heart rate, 0.83 for PR interval, 0.78 for QRS duration, and 0.89 for QTc). CONCLUSION Recordings made by this patient-operated ECG device allow to detect arrhythmias and other ECG changes with high accuracy compared with a standard ECG. It may help to improve accurate diagnosis of transient ECG changes such as paroxysmal AF in palpitations or other unexplained cardiac symptoms.