Non-Invasive Characterization of Cardiac Activation Patterns: Contributions of Body Surface Potential Mapping in Healthy Volunteers

João Salinet1, Jimena Paredes2, Marcelo Mazzetto3, Victor Gonçalves Marques4, Nelson Samesima5, Carlos Alberto Pastore6, Idágene Cestari3
1CECS, Federal ABC University, 2Biomedical Engineering, Engineering, Modelling and Applied Social Sciences Centre, Federal University of ABC, Brazil, 3Bioengineering Department, Heart Institute (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, 4Federal University of ABC, 5Clinical Unit of Electrocardiography, Heart Institute (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, 6Instituto do Coracao (InCor), Hospital das Clinicas FMUSP, Faculdade de Medicina, Universidade de Sao Paulo


Abstract

Introduction: Recently, we have developed a body surface potential map-ping (BSPM) system with 62-channel, but validation in humans is still lack-ing. In this study, we validated the system in healthy volunteers prior to ex-panding the clinical studies for patients with cardiac disorders. Methods: Sixty-two body surface electrodes are used to record 2 minutes from 21 volunteers with no previous history of cardiovascular diseases. 4 consecutive beats from the 12-lead ECG + 2 leads on the back were segmented to obtain P, QRS and T peaks and segments duration. Orthogonal vectorcardiograms (VCG) and their respective Frontal, Horizontal and Sagit-tal planes are obtained directly (DM) from electrodes positioned according to the Frank’s lead system and indirectly by three distinct methods Inverse Dower (ID), Uijen (UI) and Willems (WI). 17 instants of time during one heart beat (P-QRS-T) are used to generate sequential isopotential maps to investigate of highest and lowest potentials propagation. Results: Volunteers (age: 27±6 years, IMC: 23.96±3.06) were all male. P-QRS-T wave peaks and intervals (R-R, PR, QRS, ST and QT) are within the expected values. The P-QRS-T loops showed propagation on both clock and anti-clockwise directions, with percentages similar to those previously re-ported. Quadrant's loop locations are concentrated on both 1st or 4th. ID, UI and WI methods agreed with DM (quadrant location and rotation). UI showed a greater similarity with DM. A higher similarity (> 80%) was ob-served between ID and EU methods. Propagation of minima and maxima showed location of the receding and approaching depolarization surfaces (P and QRS), polarity is reversed during repolarization (T wave). Conclusion: The developed equipment now validated in healthy volunteers is the first in Brazil and showed results similar to those previously observed in the literature. Now the system is going to be used in patients with heart rhythm disorders.