title: Functional reentry in cultured monolayers of neonatal rat cardiac cells.
abstract: Previous studies of reentrant arrhythmias in the heart have been performed in computer models and tissue experiments. We hypothesized that confluent monolayers of cardiac cells can provide a simple, controlled, and reproducible experimental model of reentry. Neonatal rat ventricular cells were cultured on 22-mm-diameter coverslips and stained with the voltage-sensitive dye RH-237. Recordings of transmembrane potentials were obtained from 61 sites with the use of a contact fluorescence imaging system. An electrical field stimulus, followed by a point stimulus, induced 39 episodes of sustained reentry and 21 episodes of nonsustained reentry. Sustained reentry consisted of single-loop (n = 18 monolayers) or figure-of-eight (n = 4) patterns. The cycle length, action potential duration at 80% repolarization, and conduction velocity were (in means +/- SE) 358 +/- 33 ms, 118 +/- 12 ms, and 12.9 +/- 1.0 cm/s for single loop and 311 +/- 78 ms, 137 +/- 18 ms, and 7.8 +/- 1.3 cm/s for figure-of-eight, respectively. Electrical termination by 6- to 13-V/cm field pulses or 15- to 20-V point stimuli was successful in 60% of the attempts. In summary, highly stable reentry can be induced, sustained for extensive periods of time, and electrically terminated in monolayers of cultured neonatal rat cardiac myocytes.
authors.affiliation: Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: Shahriar
authors.initials: S
authors.lastname: Iravanian
authors.forename: Yelena
authors.initials: Y
authors.lastname: Nabutovsky
authors.forename: Chae-Ryon
authors.initials: CR
authors.lastname: Kong
authors.forename: Sumita
authors.initials: S
authors.lastname: Saha
authors.forename: Nenad
authors.initials: N
authors.lastname: Bursac
authors.forename: Leslie
authors.initials: L
authors.lastname: Tung
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D002478:Cells, Cultured; D004558:Electric Stimulation; D004562:Electrocardiography; D004594:Electrophysiology; D005456:Fluorescent Dyes; D006321:Heart / Q000502:physiology; D009206:Myocardium / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D005456:Fluorescent Dyes