title: Singular Value Decomposition of Optically-Mapped Cardiac Rotors and Fibrillatory Activity.
abstract: Our progress of understanding how cellular and structural factors contribute to the arrhythmia is hampered in part because of controversies whether a fibrillating heart is driven by a single, several, or multiple number of sources, and whether they are focal or reentrant, and how to localize them. Here we demonstrate how a novel usage of the neutral singular value decomposition (SVD) method enables the extraction of the governing spatial and temporal modes of excitation from a rotor and fibrillatory waves. Those modes highlight patterns and regions of organization in the midst of the otherwise seemingly-randomly propagating excitation waves. We apply the method to experimental models of cardiac fibrillation in rabbit hearts. We show that the SVD analysis is able to enhance the classification of the heart electrical patterns into regions harboring drivers in the form of fast reentrant activity and other regions of by-standing activity. This enhancement is accomplished without any prior assumptions regarding the spatial, temporal or spectral properties of those drivers. The analysis corroborates that the dominant mode has the highest activation rate and further reveals a new feature: A transfer of modes from the driving to the passive regions resulting in a partial reaction of the passive region to the driving region.
authors.affiliation: Physics Department, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Rabinovitch
authors.affiliation: Physics Department, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Biton
authors.affiliation: Physics Department. Sami Shamoon College of Engineering, Beer-Sheva, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Braunstein
authors.affiliation: Department of Information Systems Engineering, Ben-Gurion University, Beer Sheva 84105, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Friedman
authors.affiliation: Physics Department, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
authors.forename: I
authors.initials: I
authors.lastname: Aviram
authors.affiliation: Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yandrapalli
authors.affiliation: Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: S V
authors.initials: SV
authors.lastname: Pandit
authors.affiliation: Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: O
authors.initials: O
authors.lastname: Berenfeld
keywords: Singular Value Decomposition; dominant frequency; phase analysis; rotors; ventricular fibrillation