Atrial action potential heterogeneity measured by unipolar electrograms.
Vagally-induced action potential duration (APD) heterogeneity can lead to the breakdown of atrial flutter into fibrillation. The exact distribution of vagal mediated effects in the atria is unknown, however. This study analyzed canine electrograms in order to determine changes in APD. Electrograms were recorded under control, and left and right vagal nerve stimulation. Simulations in a computer model were first performed in order to determine how local acetylcholine concentrations affect electrograms. Two measures were investigated to assess APD changes. Results indicate that APD is reduced nonuniformly, and contralateral effects were seen.
Vigmond
Edward J
EJ
Dept. of Electrical & Computer Enginering, University of Calgary, Alberta, Canada.
Tsoi
Vincent
V
Pagé
Pierre
P
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D016275:Atrial Function / Q000502:physiology*; D018780:Body Surface Potential Mapping / Q000379:methods*; D003198:Computer Simulation; D004285:Dogs; D004558:Electric Stimulation / Q000379:methods; D006325:Heart Atria / Q000294:innervation; D006329:Heart Conduction System / Q000502:physiology*; D008955:Models, Cardiovascular; D014630:Vagus Nerve / Q000502:physiology*