title: Triphasic and quadriphasic waveforms are superior to biphasic waveforms for synchronized beating of cardiomyocytes.
abstract: OBJECTIVE
  Within pacemaker research few attempts have been made to find an optimal waveform phase sequence that synchronizes beating of cardiomyocytes at an electrode. Multielectrode arrays (MEAs) offer electrophysiological screening of cardiomyocytes serving as a system for preliminary screening of pacing waveform design.
  
  
  METHODS
  The HL-1 cell line was cultured in MEAs until confluence and stimulated with biphasic, triphasic, and quadriphasic waveforms. The amplitudes required for synchronized beating of the cells were determined.
  
  
  RESULTS
  Triphasic and quadriphasic waveforms were more efficient in eliciting synchronized beating of the HL-1 cells compared with the biphasic waveform because it allows significant reductions in synchronizing voltage amplitudes and reductions in supplied stimulus.
  
  
  CONCLUSIONS
  The MEA system allows for a straightforward manner to investigate effects of waveform design on synchronized beating in cardiomyocytes in vitro. Increased number of phase changes in a pacing waveform seems to be the major reason for the reduction in synchronizing amplitudes.
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, The Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden. lars.enochson@gu.se
authors.forename: Lars
authors.initials: L
authors.lastname: Enochson
authors.forename: Joakim
authors.initials: J
authors.lastname: Sandstedt
authors.forename: Hans
authors.initials: H
authors.lastname: Strandberg
authors.forename: Cecilia
authors.initials: C
authors.lastname: Emanuelsson
authors.forename: Andreas
authors.initials: A
authors.lastname: Ornberg
authors.forename: Anders
authors.initials: A
authors.lastname: Lindahl
authors.forename: Camilla
authors.initials: C
authors.lastname: Karlsson
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002460:Cell Line; D004566:Electrodes; D051379:Mice; D032383:Myocytes, Cardiac / Q000502:physiology*; D010138:Pacemaker, Artificial