Julia Mayer

Fluoroscopy integrated 3D mapping significantly reduces radiation exposure during ablation for a wide spectrum of cardiac arrhythmias

AIMS Despite the use of established 3D-mapping systems, invasive electrophysiological studies and catheter ablation require high radiation exposure of patients and medical staff. This study investigated whether electroanatomic catheter tracking in prerecorded X-ray images on top of an existing 3D-mapping system has any impact on radiation exposure. METHODS AND RESULTS Two hundred and ninety-five consecutive patients were either ablated with the guidance of the traditional CARTO-3 system (c3) or with help of the CARTO-UNIVU system (cU): [typical atrial flutter (AFL) n = 58, drug refractory atrial fibrillation (AF) n = 81, ectopic atrial tachycardia (EAT) n = 37, accessory pathways (APs) n = 22, symptomatic, idiopathic premature ventricular complexes (PVCs) n = 56, ventricular tachycardias (VTs) n = 41]. The CARTO-UNIVU allowed a reduction in radiation exposure: fluoroscopy time: AFL c3: 8.6 ± 0.8 min vs. cU: 2.9 ± 0.3 min, P < 0.001; AF c3: 16.0 ± 1.3 min vs. cU: 6.4 ± 0.9 min, P < 0.001; EAT c3: 23.4 ± 3.1 min vs. cU: 9.7 ± 1.7 min, P < 0.001; AP c3: 7.1 ± 1.2 min vs. cU: 6.0 ± 1.5 min, P = 0.59; PVCs c3: 17.6 ± 2.3 min vs. cU: 15.2 ± 2.8 min, P = 0.52; VT c3: 31.4 ± 3.4 min vs. cU: 17.5 ± 2.4 min, P = 0.003. Corresponding to the fluoroscopy time the fluoroscopy dose was also reduced significantly. These advantages were not at the cost of increased procedure times, periprocedural complications, or decreased acute ablation success rates. CONCLUSION In a wide spectrum of cardiac arrhythmias, and especially in AF and VT ablation, fluoroscopy integrated 3D mapping contributed to a dramatic reduction in radiation exposure without prolonging procedure times and compromising patients safety. That effect, however, could not be maintained in patients with APs and PVCs.

Reduction of radiation exposure during atrial fibrillation ablation using a novel fluoroscopy image integrated 3-dimensional electroanatomic mapping system: A prospective, randomized, single-blind, and controlled study

OBJECTIVE We explored whether the use of a novel fluoroscopy image integrated 3-dimensional electroanatomic mapping (F-EAM) system could result in a reduction of overall fluoroscopy time and radiation doses during the whole procedure of atrial fibrillation (AF) ablation. METHODS Eighty patients (44 men (55%); mean age 63 ± 10 years) who underwent catheter ablation due to paroxysmal AF were recruited consecutively in the present study. Patients were randomized (1:1) into 2 arms for AF ablation: one using a conventional 3-dimensional electroanatomical mapping (EAM) system and the other using the F-EAM system. RESULTS Fluoroscopy time (10:42 [interquartile range {IQR} 8:45-12:46] minutes:seconds vs 1:45 [IQR 1:05-2:22] minutes:seconds; P < .001) and radiation doses (2440 [IQR 1593-3091] cGy·cm(2) vs 652 [IQR 326-1489] cGy·cm(2); P < .001) in the EAM group were significantly greater than those in the F-EAM group. The majority of reduction of radiation exposure was achieved after transseptal puncture, which was near-zero fluoroscopic exposure. In total, approximately 84% of fluoroscopy time and 73% of radiation doses have been reduced during the AF ablation procedure using the F-EAM system compared to using the conventional EAM system. However, procedure time did not differ significantly (1:39 [IQR 1:18-2:10] hours:minutes vs 1:37 [IQR 1:17-1:50] hours:minutes; P = .362). During follow-up (5.9 ± 1.3 months), 61 patients (76.3%) had no recurrence of atrial arrhythmias. The recurrence rate between the 2 groups did not differ. CONCLUSION AF catheter ablation using the F-EAM system was safe and resulted in a significant reduction of radiation exposure to patients and staff without complicating the workflow of the procedure. A near-zero fluoroscopic catheter ablation procedure could be performed without compromising acute/mid-term efficacy and safety.

Epicardial Ventricular Tachycardia Ablation in a Patient With Brugada ECG Pattern and Mutation of PKP2 and DSP Genes

The Brugada syndrome (BS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) are currently seen as 2 distinct clinical entities. However, several genetic mutations linked to reduced sodium transmembrane flow and disrupted integrity of the desmosome with resulting fatty infiltration have been identified, corresponding to BS and ARVC, respectively.1 A 22-year-old male patient was admitted to our hospital with repeated discharges of the implantable cardioverter defibrillator caused by pleomorphic ventricular tachycardia. He had a previous history of survived sudden cardiac death and an implanted single-chamber implantable cardioverter defibrillator in 2010. No data on work-up of genetic arrhythmias had been available to date. On current clinical presentation in echocardiography, normal ejection fraction and heart diameter could be determined. Because of abnormal ECG pattern in a sense of an incomplete right bundle branch block with slightly elevated ST-segments and T-wave inversions in the right precordial leads, an ajmaline test was conducted (Figure A). This resulted in prominent coved-type Brugada ECG (Figure B). Figure. A , Baseline …

Prevalence and predictors of low voltage zones in the left atrium in patients with atrial fibrillation

Aims To describe the extent and distribution of low voltage zones (LVZ) in a large cohort of patients undergoing ablation for paroxysmal and persistent atrial fibrillation (AF), and to explore baseline predictors of LVZ in these patients. Methods and results Consecutive patients who underwent a bipolar voltage map guided AF ablation, were enrolled. Voltage maps were conducted for each patient using 3-dimensional electroanatomical mapping system and LVZ were defined as areas of bipolar voltage < 0.5 mV. A total of 539 patients (309 male, age 65 ± 10 years) were included. Low voltage zones was present in 58 out of 292 patients with paroxysmal and 134 out of 247 persistent AF (P < 0.001). The area of LVZ was larger in patients with persistent as compare to paroxysmal AF, 5 cm2 (IQR 3-18.6) vs. 12.1 cm2 (IQR 3.6-28.5), P = 0.026, respectively. In the multivariate analysis age (OR 1.07, 95%CI 1.05-1.10, P < 0.001), female gender (OR 2.18, 95%CI 1.38-3.43, P = 0.001), sinoatrial node dysfunction (OR 3.90, 95%CI 1.24-12.21, P = 0.020), larger surface area of left atrium pr. cm2 (OR 1.01, 95%CI 1.00-1.02, P = 0.016), and persistent AF (OR 5.03, 95%CI 3.20-7.90, P<0.001) were associated with presence of LVZ. Conclusion In a large cohort of patients undergoing ablation for AF, the prevalence of LVZ was higher and LVZ areas larger in patients with persistent as compared with paroxysmal AF. The most frequent localization of LVZ was anterior wall, septum and posterior wall. Presence of LVZ was associated with higher age, female gender, larger LA surface area, and sinoatrial node dysfunction.

Continuous monitoring after atrial fibrillation ablation: the LINQ AF study

Abstract Aims To study device performance, arrhythmia recurrence characteristics, and methods of outcome assessment using a novel implantable cardiac monitor (ICM) in patients undergoing ablation for atrial fibrillation (AF). Methods and results In 419 consecutive patients undergoing first-time catheter ablation for symptomatic paroxysmal (n = 224) or persistent (n = 195) AF an ICM was injected at the end of the procedure. Telemedicine staff ensured full episode transmission coverage and manually evaluated all automatic arrhythmia episodes. Device detection metrics were calculated for ≥2, ≥6, and ≥10 min AF detection durations. Four methods of outcome assessment were studied: continuous recurrence analysis, discontinuous recurrence analysis, AF-burden analysis, and analysis of individual rhythm profiles. A total of 43 673 automatic AF episodes were transmitted over a follow-up of 15 ± 6 months. Episode-based positive predictive values changed significantly with longer AF detection durations (70.5% for ≥2 min, 81.8% for ≥6 min, and 85.9% for ≥10 min). Patients with exclusive short episode recurrences (≥2 to <6 min) were rare and their arrhythmia detection was clinically irrelevant. Different methods of outcome assessment showed a large variation (46–79%) in ablation success. Individual rhythm characteristics and subclinical AF added to this inconsistency. Analysis of AF-burden and individual rhythm profiles were least influenced and showed successful treatment in 60–70% of the patients. Conclusion We suggest AF detection duration >6 min and AF burden >0.1% as a standardized outcome definition for AF studies to come in the future.

Endo-/Epicardial Catheter Ablation of Atrial Fibrillation: Feasibility, Outcome, and Insights Into Arrhythmia Mechanisms

Background: Until today, catheter interventional mapping and ablation of atrial fibrillation (AF) has been limited to the right and left atrial endocardium. We report feasibility, electrophysiological findings, and clinical outcome using a combined endo-/epicardial catheter approach for mapping and ablation of AF. Methods and Results: Fifty-nine patients with permanence of pulmonary vein isolation and further symptomatic recurrences of paroxysmal AF, persistent AF, or atrial tachycardia underwent reablation using biatrial endo-/epicardial mapping and ablation. Identification of arrhythmia substrates and selection of ablation strategy were based on sinus rhythm voltage mapping. Using continuous monitoring and a 3-month blanking period, freedom from AF/atrial tachycardia ≥2 minutes was defined as primary end point. In all patients, endo-/epicardial mapping and ablation was feasible using standard technologies of catheter access, 3-dimensional mapping, and radiofrequency ablation. Epicardial mapping and ablation did not add procedural risks. Exclusively epicardial low voltage substrates were found in 14% of the patients. For the first time, novel epicardial conduction abnormalities located in the epicardial fiber network were described in human AF patients (19% of the cohort). Epicardial ablation was needed in 80% of the patients. Over 23±10 months of follow-up freedom from arrhythmia recurrences measured 73%. Conclusions: Catheter-based endo-/epicardial mapping and ablation of AF was feasible and safe. Epicardial mapping provided new insights into AF mechanisms. Epicardial ablation increased transmurality of ablation lesions. Clinical outcome in this cohort of complex AF patients was favorable, indicating potential further development of current AF treatment.