Banca de DEFESA: JIMENA GABRIELA SILES PAREDES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JIMENA GABRIELA SILES PAREDES
Data: 25/08/2026
HORA: 14:00
LOCAL: Sala 107 Bloco Zeta Campus São Bernardo do Campo
TÍTULO:

DUAL OPTICAL AND ELECTRICAL MAPPING REVEALS ELECTROPHYSIOLOGICAL PATTERNS OF CARDIAC ARRHYTHMIAS: FROM ANIMAL TO HUMAN MODELS

PÁGINAS: 150
RESUMO:

Introduction: Cardiac arrhythmias affect one in three people worldwide, with atrial fibrillation (AF) impacting over 37.6 million individuals and ventricular arrhythmias, such as ventricular tachycardia (VT) and fibrillation (VF), remaining major causes of sudden cardiac death. A better understanding of their underlying mechanisms is crucial to refine clinical metrics and improve patient management. Thus, it is hypothesized that integrating high-resolution optical mapping with conventional electrical mapping can reveal electrophysiological patterns that enhance the interpretation of arrhythmia mechanisms.

Methods: This study was conducted in three experimental stages. First, a panoramic epicardial approach was developed in Langendorff-perfused rabbit hearts to characterize arrhythmogenic mechanisms beyond single-site analyses. Three synchronized high-speed cameras were arranged 120° apart around the heart. Simultaneously, three custom-designed multielectrode arrays (MEAs) were placed on the right atrium, left atrium, and ventricular surfaces. This setup enabled time-domain and phase analyses during sinus rhythm and atrial/ventricular arrhythmias. In the second stage, a dual optical-electrical mapping platform was implemented to assess transmural differences in healthy porcine and structurally pathological human hearts. Optical signals were recorded from both endocardial and epicardial surfaces using two optical cameras, while two custom MEAs were placed in direct tissue contact. Action potential duration (APD) at 70%, 80%, and 90% repolarization was compared with activation–recovery interval (ARI) calculated using Wyatt and alternative methods across 16 sites and three consecutive beats. Finally, the third stage investigated arrhythmic vulnerability by constructing APD80-based restitution curves during incremental pacing.

Results: The panoramic mapping system successfully analyzed sinus rhythm with AV block (SR/AVB), VT with premature atrial contraction, and AF. Cycle lengths were nearly identical in SR/AVB, showed moderate discrepancies in VT (5–20 ms), and exhibited greater variability in AF. Comparisons between APD and ARI revealed layer -and species- dependent differences, with pathological human hearts showing greater variability. Porcine hearts displayed stable restitution curves, transitioning directly from 1:1 rhythm to VF without alternans, whereas pathological human hearts exhibited marked endocardial alternans with large APD variations.

Conclusion: Dual optical-electrical mapping provides a comprehensive experimental framework to investigate arrhythmogenic mechanisms across species and cardiac surfaces. By revealing electrophysiological patterns that complement conventional electrical analysis, this approach enhances the understanding of arrhythmia dynamics and offers valuable insights for future translational applications.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 2231661 - JOAO LOURES SALINET JUNIOR
Membro Titular - Examinador(a) Interno ao Programa - 1600858 - HERCULANO DA SILVA MARTINHO
Membro Titular - Examinador(a) Externo ao Programa - 1188948 - JOAO LAMEU DA SILVA JUNIOR
Membro Titular - Examinador(a) Externo à Instituição - ROBERT SCOTT MACLEOD
Membro Titular - Examinador(a) Externo à Instituição - OMER BERENFELD
Membro Suplente - Examinador(a) Externo à Instituição - JURANDIR NADAL - UFRJ
Membro Suplente - Examinador(a) Externo à Instituição - RODRIGO WEBER DOS SANTOS - UFJF