Abstract 16564: Location of Persistent Atrial Fibrillation Drivers Based on Body Surface Mapping: A Systematic Review and Metanalysis

Introduction: Body Surface Mapping (BSM) is a non-invasive electrocardiogram-based mapping system that is used to identify localized drivers in patients with persistent Atrial Fibrillation (AF). Mapping of local drivers is becoming increasingly important in guiding treatment of atrial fibrillation but may not be readily available. We conducted a systematic review to determine the most prevalent atrial regions of AF driver activity identified with BSM. Methods: Electronic literature searches were performed across PubMed, Google Scholar, Cochrane, CINAHL, Web of science, EMBASE databases up to January 2019, for studies that utilized BSM to identify and report localized focal and rotor (reentrant) driver activity. Prevalence of drivers, as a percentage, were recorded for every region according to the Bordeaux Biatrial Schema. Random-effects model was used to calculate weighted averages with the corresponding 95% confidence interval (CI). Results: Total of 468 unique studies were identified and reviewed. 4 prospective cohort studies were included in the final analysis—of which 3 were single-center and 1 was multi-centered; totaling 336 patients. The mean age was 62.8 (±5.41) and 73% were males. The three most prevalent regions with persistent AF foci activity were region 1 (left pulmonary veins and left appendage): 59% (CI 48-71), followed by region 4 (upper half of right atrium and appendage): 31% (CI 12-54), and region 2 (right pulmonary veins and posterior interatrial groove): 19% (CI 7-34). The three most prevalent regions of persistent AF rotor activity were region 3 (inferior and posterior left atrium): 71% (CI 32-98), region 1: 70% (CI 21-100), and region 2: 70% (CI 25-99). Conclusion: In patients with persistent AF, majority of localized drivers seem to originate from specific atrial regions based on BSM.

Abstract 15668: Noninvasive Mapping Can Predict Success of Ablation for Atrial Fibrillation

Introduction: It is currently not possible to non-invasively identify patients with atrial fibrillation (AF) who may respond acutely to ablation. We hypothesized that high resolution body surface mapping can identify specific distributions of AF in individuals that predict acute success from ablation. Objective: To correlate 64 lead body surface ECG in AF to acute ablation response and non-invasively identify patients in whom ablation does and does not terminate AF. Method: Fig A shows 64 body surface electrodes in N=17 consecutive AF patients (14 persistent AF, 67 ± 9.06 years). Spectral dominant frequency (DF) from 4096-point FFT, cycle length, AF electrogram amplitude were measured in 200-300 time slices of duration 60s between patches on the body surface representing each atrium (Fig A). Results: Ablation terminated AF in N=7/17 patients (41.2%, Fig. B). Patients with AF termination had more organized AF than those without termination, indicated by lower DF on body surface mapping of the regions corresponding to left (5.00 ± 1.33 vs 5.47 ± 1.30, p < 0.001) and right atrium (5.16 ± 1.50 vs 5.50 ± 1.01, p < 0.003) (Fig C shows composite). DF was stable without statistically significant variations across 20s slices spanning the full minute, supporting interpretability of mechanisms from this analysis (p = NS). Further, AF signal amplitude averaged across left and right atria was lower in patients with AF termination (65.47 ± 36.9 vs 120.13 ± 99.9, p < 0.001) (Fig D). Conclusion: Body surface analysis of AF can non-invasively identify patients in whom ablation may acutely terminate AF. Future studies should determine if this approach can predict who may ultimately achieve long term freedom from AF, and whether body surface signatures are representative enough to be analyzed days prior to the procedure.

QRS dispersion using 252-leads Body Surface Mapping (BSM) – an explorative study of a novel diagnostic tool for Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

Background The diagnosis of ARVC is complex and challenging requiring multiple investigational tools, most of which include the demonstration of depolarization/conduction abnormalities, described in recent HRS consensus documents 2019. A simple and user friendly diagnostic tool is warranted. Purpose The purpose of our study was therefore to explore whether the analysis of QRS dispersion obtained from 252-leads recorded by a Body Surface Mapping (BSM) system can be used to identify ARVC patients as compared to the traditional ECG criteria including QRS dispersion measured by conventional 12 lead surface ECG. Methods 12 definite ARVC patients (10/12 with known pathogenic mutation) (Group 1) and 8 healthy family members tested negative for the family mutation served as controls (Group 0), were included. All patients underwent 12-lead ECG (50mm/sec), Signal-averaged ECG for late potentials and 252 lead BSM recordings. The QRS duration was measured in each of the 12 ECG leads manually with digital caliper. The QRS duration from the BSM leads were manually analyzed in Matlab by two observers unaware of the diagnosis. For each lead, the mean value of three randomly chosen beats was calculated. The QRS dispersion was calculated as the difference between the minimum and maximum value for both the 12 lead ECG and the BSM recordings. Results The mean age was 49,6 and 38,8 years in ARVC patients and controls, respectively. The number of males in the two groups were 8/12 and 5/8, respectively. Epsilon waves and Terminal Activation Duration (TAD) &gt;55msec were detected in 6/12 and 8/12 ARVC patients, respectively, but in no controls. Late potentials were detected in 11/12 ARVC patients and in 2 controls. The QRS duration and QTc duration was not statistically different in the two Groups. The ECG-QRS dispersion was significantly more pronounced in Group 1 (42 ms ± 15, range 20–70 ms) than in Group 0 (26 ms ± 8, range 16–36 ms) (p=0.013). The BSM-QRS dispersion was significantly longer in Group 1 (68 ms ± 17, range 29–90ms) than in Group 0 (30 ms ± 7, range 22–41ms) (p=0.001). Only one ARVC patient had a BSM-QRS dispersion &lt;50 msec, whereas none of the controls had a QRS dispersion over 50 msec (Fig. 1). Conclusion BSM-QRS dispersion, specifically using the cut off &lt;50 ms, can potentially be a more sensitive and specific method than other ECG related techniques for diagnosing ARVC patients versus non-ARVC patients. Larger patient cohorts and further studies are required to confirm our findings. Figure 1. ECG and BSM-QRS dispersion Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Selanders Stiftelse