title: Feasibility of high-density electrophysiological study using multiple-electrode array in isolated small animal atria.
abstract: 1. High-density cardiac electrophysiological study (EPS) of small animal atria has been limited to optical mapping techniques, which require complex and expensive equipment setup. We aim to evaluate the feasibility of carrying out EPS in isolated atrial tissues using a custom made high-density multiple-electrode array (MEA). 2. Isolated rat atrial preparations were studied. The MEA (4 × 5 mm) consisted of 90 silver chloride coated electrodes (0.1 mm diameter, 0.5 mm pitch) and was connected to a conventional EP system yielding 80 bipolar signals. Atrial tissues were placed over the MEA in a dish bubbled with 100% oxygen and superfused with modified HEPES solution at pH 7.35 and 37°C. Then, 1 mmol of 2,3-butanedione monoxime was added to suppress motion artifacts from muscle contractions. Custom plaque analysis software was used for offline conduction analysis. 3. Isolated atrial tissues showed good viability of > 30 min, allowing ample time for complete EPS. High quality electrograms with excellent signal to noise ratio were obtained. All electrophysiological parameters showed good reproducibility: effective refractory period, conduction velocity and heterogeneity index. Tachycardia was also inducible in these normal atria. 4. The present study shows the feasibility of performing high-density EPS of small isolated atrial tissues with a conventional electrode-based technique. The MEA system is compatible with standard electrophysiology recording systems and provides a novel, inexpensive option for detailed EPS in small animal models. In particular, it presents new research avenues to further explore the mechanisms of atrial arrhythmias in various transgenic and knockout rodent models.
authors.affiliation: Cardiovascular Research Centre, Department of Cardiology, Royal Adelaide Hospital, Disciplines of Medicine and Physiology, University of Adelaide, Adelaide, Australia.
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Lau
authors.forename: Lorraine
authors.initials: L
authors.lastname: Mackenzie
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Shipp
authors.forename: Pawel
authors.initials: P
authors.lastname: Kuklik
authors.forename: Hany
authors.initials: H
authors.lastname: Dimitri
authors.forename: Bruce L W
authors.initials: BL
authors.lastname: Lobb
authors.forename: Muayad
authors.initials: M
authors.lastname: Alasady
authors.forename: Han S
authors.initials: HS
authors.lastname: Lim
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Kelly
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Brooks
authors.forename: David A
authors.initials: DA
authors.lastname: Saint
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
mesh_terms: D000818:Animals; D016275:Atrial Function / Q000502:physiology*; D022062:Electrophysiologic Techniques, Cardiac / Q000295:instrumentation* / Q000379:methods*; D005240:Feasibility Studies; D006325:Heart Atria; D017736:Ion-Selective Electrodes; D051381:Rats; D011921:Rats, Inbred WKY