Optical Mapping System for Visualizing Arrhythmias in Isolated Mouse Atria

Abstract

Optical mapping has become an important technique in the study of cardiac electrophysiology, especially in terms of investigating the mechanisms of cardiac arrhythmias. The increasing availability of transgenic mice as models for cardiovascular disease is driving the need for instrumentation suitable for the study of electrical activity in the mouse heart. In this paper we evaluate our optical mapping system's ability to clearly record induced arrhythmic activity in an isolated mouse atrial preparation. Preliminary results indicate that the signal quality is high enough that individual optically recorded action potentials can be discerned in many pixels, even without post-processing for noise removal. The optical mapping video is clear enough for general observations regarding the patterns of electrical propagation during arrhythmic behaviour. The induced arrhythmias appear to have a regular pattern of activity, and are likely best classified as atrial tachycardias.

A novel system for mapping regional electrical properties and characterizing arrhythmia in isolated intact rat atria

“…Numerous optical mapping studies have been carried out in isolated murine atrial preparations, because they are sufficiently thin walled for adequate metabolic support to be provided by superfusion. As atrial geometry is complex, mapping of mouse and rat atria has either been restricted to small regions (8,12,13) or the atria have been dissected and flattened (2,(14)(15)(16)(17)(18)(19). Although the latter approach offers a better view of global activity, dissection can alter the structural integrity of atrial myocardium and interrupt electrical pathways that may contribute to reentry.…”