3D-Mapping of QRS Loops: Visualizing the Ventricular Electrical Activities

This paper presents innovative visualization tools for the analysis and interpretation of three-dimensional vectorcardiogram (VCG), focusing on the QRS complex of the cardiac cycle. Traditional electrocardiography (ECG) lacks the spatial detail necessary for comprehensive cardiac evaluations; however, VCG provides a three-dimensional representation of electrical activity in the heart, allowing for a nuanced understanding of cardiac dynamics. We propose five distinct methodologies for representing spatial QRS VCG loops: (1) unmodified spatial VCG loops that track the progression of ventricular depolarization, (2) fixed-scale VCG loops that facilitate direct comparisons across individuals and conditions, (3) orientation of QRS loop with respect to three orthogonal planes in the 3D space. (4) octant-specific plots that offer insights into spatial distributions, and (5) unit vector and unit sphere representations that emphasize directional movement while normalizing magnitude. Each method has unique strengths in elucidating ventricular electrodynamics in normal and in cardiac conditions such as anterior wall myocardial infarction and inferior wall myocardial infarction, highlighting differences in loop size, directionality of propagation, orientation, and morphology. Together, these methodologies provide a robust framework for advancing VCG research and enhancing clinical assessments of cardiac function. Preliminary findings highlight the potential of these innovative tools.