title: Action potential duration gradients in the heart ventricles and the cardiac electric field during ventricular repolarization (a model study).
abstract: BACKGROUND
  We simulated contributions of transmural, apicobasal, anteroposterior and interventricular action potential duration (APD) gradients to the body surface potential distribution (BSPD) with constant or varied magnitudes of the transmural and apicobasal gradients.
  
  
  METHODS
  Simulations were done in the framework of the discrete computer model of the rabbit heart ventricles on the basis of realistic activation sequence and APDs. The APD gradients were set constant at 20 ms or varied in the range of ±80 ms.
  
  
  RESULTS
  The apicobasal, transmural and interventricular APD gradients of 20 ms produced similar BSPDs, whereas the BSPD inversion was caused by the inverted apicobasal or transmural 80 ms gradients. The transmural APD gradient produced transversal and mainly apicobasal T-wave vectors due to wall curvature and cancellation effects. The "normal" transversal and apicobasal repolarization gradients were decreased and increased by activation sequence, respectively.
  
  
  CONCLUSIONS
  The different APD gradients contributed consistently to the development of BSPD.
authors.affiliation: Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50, Pervomayskaya St., Syktyvkar, Russia.
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Arteyeva
authors.affiliation: Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50, Pervomayskaya St., Syktyvkar, Russia; Department of Physiology, Medical Institute of Syktyvkar State University, 11, Babushkin St., Syktyvkar, Russia. Electronic address: j.azarov@gmail.com.
authors.forename: Jan E
authors.initials: JE
authors.lastname: Azarov
authors.affiliation: Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50, Pervomayskaya St., Syktyvkar, Russia; Department of Physiology, Medical Institute of Syktyvkar State University, 11, Babushkin St., Syktyvkar, Russia.
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Vityazev
authors.affiliation: Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 50, Pervomayskaya St., Syktyvkar, Russia.
authors.forename: Dmitry N
authors.initials: DN
authors.lastname: Shmakov
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D018780:Body Surface Potential Mapping / Q000379:methods*; D003198:Computer Simulation; D006329:Heart Conduction System / Q000502:physiology*; D008955:Models, Cardiovascular; D011817:Rabbits; D016276:Ventricular Function / Q000502:physiology*
keywords: APD gradient; Activation; Body surface potential distribution; Rabbit; Repolarization; T-vector