Simulation of Reentrant Propagation in Cardiac Tissue

Abstract

A uniform and continuous ring model of cardiac tissue was used to simulate reentry around a fixed obstacle. Stable one-dimensional reentry was obtained with a sufficiently long ring, and complete block occurred below a minimum ring length. Irregular reentry was observed at intermediate ring lengths, in the form of recurrent or quasi-periodic patterns. Sustained quasi-periodic reentry was associated with a zone of slow conduction which was located on a different part of the ring at each turn. Reentry in two-dimensional myocardium was simulated by means of a rectangular sheet of parallel uniform and homogeneous identical cables. Stable two-dimensional reentry occurred around an arc of functional unidirectional block which varied in size and location at each turn. Irregular two-dimensional reentry was associated with regions of slow conduction which led to a fragmentation of the arc of unidirectional block and the generation of multiple activation fronts. Overall our simulation results with the ring model closely resemble experimental observations in a canine atrial tissue ring around the tricuspid orifice (1). Similarly our results on simulated two-dimensional reentry are in accord with experimental observations in isolated strips of myocardium (2).