María S Guillem

• PhD
• Polytechnic University of Valencia

Background Complexity and signal recurrence metrics obtained from body surface potential mapping (BSPM) allow quantifying atrial fibrillation (AF) substrate complexity. This study aims to correlate electrocardiographic imaging (ECGI) detected reentrant patterns with BSPM-calculated signal complexity and recurrence metrics. Methods BSPM signals wer...

Background The mechanisms responsible for atrial fibrillation (AF) are not yet fully understood and treatment strategies remain suboptimal. Electrocardiographic imaging (ECGi) could provide new insights into the arrhythmogenic substrate’s characterization. Objective To validate a novel imageless ECGi technique against electroanatomical mapping (EA...

Background Left bundle branch pacing (LBBP) has emerged as a promising alternative technique for cardiac resynchronization therapy (CRT). ECG imaging (ECGI) may provide an accurate assessment of electrical resynchronization using real-time maps during LBBP implant. Purpose To evaluate the usefulness of ECGI to guide LBBP implant, by analyzing the...

Background Atrial arrythmogenic substrate is a key determinant of arrhythmia recurrence after pulmonary vein isolation (PVI), and reduced conduction velocities have been linked to adverse outcome. However, a non-invasive method to assess such electrical substrate is not available to date. Purpose We have developed and validated a non-invasive mapp...

Background 3D imaging and high-resolution electroanatomical mapping have become an integral part of cardiac electrophysiology and the management of patients with arrhythmias. With further technological advances the significance of these modalities continues to grow. However, to perform regional quantitative analyses and intra- and inter-individual,...

Background The validation of bidirectional cavotricuspid isthmus (CTI) block following catheter ablation for typical atrial flutter (AFL) involves endocavitary manoeuvres using multiple catheters. The diagnostic capacity of electrocardiographic imaging (ECGi) as a non-invasive tool to confirm bidirectional CTI block may simplify the procedure but i...

Background Precise identification of premature ventricular contractions (PVC) origins poses a significant challenge in electroanatomic mapping. Electrocardiographic Imaging (ECGI) allows instantaneous and global activation time mapping, providing a fast way to locate the origin of ectopic contractions. However, the standard methodology to estimate...

Background Left bundle branch pacing (LBBP) may prevent right ventricular (RV) pacing-induced dyssynchrony (DYS). Nowadays, real-time assessment of DYS correction is indirectly measured with QRS narrowing. Non-invasive ECG imaging (ECGI) technique may provide an evaluation of electrical resynchronization based on quantitative assessment of ventricu...

Background The ablation of ventricular tachycardias (VT) presents significant challenges due to the complex and time-consuming approaches involved in identifying arrhythmogenic regions. Combining non-invasive electrocardiographic imaging (ECGI) with endocardial mapping could potentially enhance the efficacy of interventions. Objective To evaluate...

Supraventricular arrhythmias, including atrial tachycardia, flutter and fibrillation are common cardiac arrhythmias, and responsible for reduction of patients’ quality of life in long term. The most common treatment is by radiofrequency catheter ablation, where a catheter with electrodes is introduced inside the atria chamber, and in contact with t...

The location of driver mechanisms in supra-ventricular tachyarrhythmias can be difficult to perform by human observers or in an automated manner, mainly when it comes to non-invasive methods. In this study, we investigated an automated methodology to locate two of the most common: Atrial Fibrillation (AF), driven by functional rotors; and atrial ta...

La capacidad de búsqueda y valoración de la información y el aprendizaje autónomo de estudiantes y profesionales son de gran relevancia en una sociedad en la que el conocimiento es amplísimo y se genera de forma muy rápida. Con objeto de trabajar estos aspectos relacionados con la competencia aprender a aprender (AaA) y la gestión de la información...

La capacidad de búsqueda y valoración de la información y el aprendizaje autónomo de estudiantes y profesionales son de gran relevancia en una sociedad en la que el conocimiento es amplísimo y se genera de forma muy rápida. Con objeto de trabajar estos aspectos relacionados con la competencia aprender a aprender (AaA) y la gestión de la información...

Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Ministerio de Ciencia, Innovación y Universidades; Generalitat Valenciana Background Electrocardiographic Imaging (ECGI) allows evaluating the cardiac substrate non-invasively. However, the inverse solution is strongly dependent on the noise of the body surface signal...

Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Generalitat Valenciana Grants Ministerio de Ciencia, Innovación y Universidades Background Personalized cardiac digital twins have been proposed as a clinical tool to plan ablation strategies during cardiac arrhythmias. However, these personalization frameworks normal...

Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported by the European Union NextGenerationEU/PRTR. Background – The non-invasive characterization of complex atrial tachyarrhythmias, including atrial flutter (AFL) and focal atrial tachycardia (AT) is challenging. Conventional...

Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This project has received funding from the European Union's Horizon Research and Innovation Programme under the Marie-Sklodowska Curie Grant Agreement No. 860974 Background Recurrence rates after atrial fibrillation (AF) ablation are still unsat...

Background and objective Electrocardiographic imaging (ECGI) has been used for guiding atrial fibrillation (AF) ablation, identifying reentrant activity by phase analysis with promising results. The objective of this study is to identify the best post-processing configuration for reentrant activity detection that better differentiates AF patients w...

Introduction Electrocardiographic Imaging is a non-invasive technique that requires cardiac Imaging for the reconstruction of cardiac electrical activity. In this study, we explored imageless ECGI by quantifying the errors of using heart meshes with either an inaccurate location inside the thorax or an inaccurate geometry. Methods Multiple‑lead bo...

The study by Strocchi et al. adds evidence that choosing the cardiac resynchronization therapy (CRT) according to the cardiac substrate of each patient could be beneficial. Perhaps the most appropriate approach in CRT would be to find the appropriate niche for each pacing method. It may be less about demonstrating the superiority of conduction syst...

Pulmonary vein isolation (PVI) is the most successful treatment for atrial fibrillation (AF) nowadays. However, not all AF patients benefit from PVI. In this study, we evaluate the use of ECGI to identify reentries and relate rotor density in the pulmonary vein (PV) area as an indicator of PVI outcome. Rotor maps were computed in a set of 29 AF pat...

The inverse problem of electrocardiography or electrocardiographic imaging (ECGI) is a technique for reconstructing electrical information about cardiac surfaces from noninvasive or non-contact recordings. ECGI has been used to characterize atrial and ventricular arrhythmias. Although it is a technology with years of progress, its development to ch...

Atrial fibrosis plays a key role in the initiation and progression of atrial fibrillation (AF). Atrial fibrosis is typically identified by a peak-to-peak amplitude of bipolar electrograms (b-EGMs) lower than 0.5 mV, which may be considered as ablation targets. Nevertheless, this approach disregards signal spatiotemporal information and b-EGM sensit...

Background and objective The prevalence of atrial fibrillation (AF) has tripled in the last 50 years due to population aging. High-frequency (DFdriver) activated atrial regions lead the activation of the rest of the atria, disrupting the propagation wavefront. Fourier based spectral analysis of body surface potential maps have been proposed for DFd...

Introduction: Electrocardiographic Imaging (ECGI) allows computing the electrical activity in the heart non-invasively using geometrical information of the patient and multiple body surface signals. In the present study we investigate the influence of the number of nodes of geometrical meshes and recording ECG electrodes distribution to compute ECG...

Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Instituto de Salud Carlos III, and Ministerio de Ciencia, Innovación y Universidades (supported by FEDER Fondo Europeo de Desarrollo Regional PI17/01106), Agencia Estatal de Investigación (RYC2018-024346B-750 and PID2020-119364RB-100), Generalitat Valen...

Atrial fibrillation (AF) is characterized by complex and irregular propagation patterns, and AF onset locations and drivers responsible for its perpetuation are the main targets for ablation procedures. ECG imaging (ECGI) has been demonstrated as a promising tool to identify AF drivers and guide ablation procedures, being able to reconstruct the el...

Background Electrocardiographic imaging (ECGI) allows evaluating the complexity of the reentrant activity of atrial fibrillation (AF) patients. In this study, we evaluated the ability of ECGI metrics to predict the success of pulmonary vein isolation (PVI) to treat AF. Methods ECGI of 24 AF patients (6 males, 13 paroxysmal, 61.8 ± 14 years) was re...

La capacidad de búsqueda y valoración de la información y el aprendizaje autónomo, son aspectos clave relacionados con la competencia aprender a aprender (AaA) y cada vez son de mayor relevancia para estudiantes y profesionales. Para el diseño de actividades formativas es de suma importancia identificar los aspectos concretos que requiren de mayor...

Electrocardiographic imaging (ECGI) is a technique to reconstruct non-invasively the electrical activity on the heart surface from body-surface potential recordings and geometric information of the torso and the heart. ECGI has shown scientific and clinical value when used to characterize and treat both atrial and ventricular arrhythmias. Regarding...

Background Multipoint pacing (MPP) in cardiac resynchronization therapy (CRT) activates the left ventricle from two locations, thereby shortening the QRS duration and enabling better resynchronization; however, compared with conventional CRT, MPP reduces battery longevity. On the other hand, electrocardiogram‐based optimization using the fusion‐opt...

Atrial fibrillation (AF) is characterized by complex and irregular propagation patterns. Noninvasive electrocardiographic imaging (ECGI) has been tested during AF conditions with promising results. However, current regularization methods face important challenges in this type of unstable electrical activity scenarios. Combination of intracardiac an...

Developed and under-developed countries are facing several challenges related to public health and sustainability of health care systems. New challenges demand of the collaborative action of multiple stakeholders with different backgrounds. In the late years, telecommunication engineers are involved in a wide range of companies and institutions to...

Background The cardiac late sodium current (INaL) has been increasingly implicated in the initiation of atrial fibrillation (AF). In fact, it has been reported that the augmentation of INaL in pathophysiological conditions prolongs repolarization and facilitates the appearance of afterdepolarizations, which can act as triggers of arrhythmic activit...

Background Mechanical stretch increases Na⁺ inflow into myocytes, related to mechanisms including stretch-activated channels or Na⁺/H⁺ exchanger activation, involving Ca²⁺ increase that leads to changes in electrophysiological properties favoring arrhythmia induction. Ranolazine is an antianginal drug with confirmed beneficial effects against cardi...

Purpose Recent investigations failed to reproduce the positive rotor-guided ablation outcomes shown by initial studies for treating persistent atrial fibrillation (persAF). Phase singularity (PS) is an important feature for AF driver detection, but algorithms for automated PS identification differ. We aim to investigate the performance of four diff...

Purpose: Atrial tachycardia (AT), flutter (AFL) and fibrillation (AF) are very common cardiac arrhythmias and are driven by localized sources that can be ablation targets. Non-invasive body surface potential mapping (BSPM) can be useful for early diagnosis and ablation planning. We aimed to characterize and differentiate the arrhythmic mechanisms b...

Objective: Atrial dominant frequency (DF) maps undergoing atrial fibrillation (AF) presented good spatial correlation with those obtained with the non-invasive body surface potential mapping (BSPM). In this study, a robust BSPM-DF calculation method based on wavelet analysis is proposed. Approach: Continuous wavelet transform along 40 scales in...

Background: It is difficult to non-invasively phenotype atrial fibrillation (AF) in a way that reflects clinical endpoints such as response to therapy. We set out to map electrical patterns of disorganization and regions of reentrant activity in AF from the body surface using electrocardiographic imaging (ECGI), calibrated to panoramic intracardiac...

Body surface potential mapping (BSPM) can be an important tool in ablation therapy planning. Results obtained with high resolution (HR) computer models must be translated to realistic numbers of leads. This study aims to evaluate the impact on atrial tachycardia (AT), flutter (AFL) and fibrillation (AF) characterization by reducing the number of BS...

Atrial tachycardia (AT), atrial flutter (AFL) and atrial fibrillation (AF) are among the most common cardiac ar-rhythmias and evidences suggest that they are driven by localized sources (ectopic focus in AT, macro-reentrant circuit in AFL and rotors in AF) that can be targeted for abla-tion. We aimed to characterize such mechanisms from the non-inv...

Background Alternans have been associated with the development of ventricular fibrillation and its control has been proposed as antiarrhythmic strategy. However, cardiac arrhythmias are a spatiotemporal phenomenon in which multiple factors are involved (e.g. calcium and voltage spatial alternans or heterogeneous conduction velocity) and how an anti...

Background: Several metabolic conditions can cause the Brugada ECG pattern, also called Brugada phenotype (BrPh). We aimed to define the clinical characteristics and outcome of BrPh patients and elucidate the mechanisms underlying BrPh attributed to hyperkalemia. Methods and Results: We prospectively identified patients hospitalized with severe hy...

Atrial Flutter (AFL) termination by ablating the path responsible for the arrhythmia maintenance is an extended practice. However, the difficulty associated with the identification of the circuit in the case of atypical AFL motivates the development of diagnostic techniques. We propose body surface phase map analysis as a noninvasive tool to identi...

Atrial fibrillation (AF) is the most prevalent heart arrhythmia in the world, being ablation of driver regions (focal sources and/or functional reentrant circuits) the most common therapy. Such regions can be detected and located non-invasively using body surface potential mapping (BSPM) systems, often using phase analysis. Narrow bandpass filterin...

Atrial fibrillation (AF) is the most prevalent heart arrhythmia in the world, being ablation of driver regions (focal sources and/or functional reentrant circuits) the most common therapy. Such regions can be detected and located non-invasively using body surface potential mapping (BSPM) systems, often using phase analysis. Narrow bandpass filterin...

Electrocardiographic imaging (ECGI) reconstructs the electrical activity of the heart from a dense array of body-surface electrocardiograms and a patient-specific heart-torso geometry. Depending on how it is formulated, ECGI allows the reconstruction of the activation and recovery sequence of the heart, the origin of premature beats or tachycardia,...

Safety pharmacology aims at detectingundesirable effect of drugs during its development. However, limitations are present at both in-vitro and in-silico level because of its low detection efficacy during this process. In this work,the effect of drugs at tissue levelwas studiedand inducibility in a multivariable scenario including 127 models tested...