RESUMO
[Abstract ] Objective Modern pharmacological studies confirmed Zhigancao Decoction total extract, single active ingredients and their combinations could obviously inhibit arrhythmia.This study was to investigate the effects of Zhigancao Decoction medicated serum combined with myocardial tissue/silicon substrate microelectrode arrays (MEA) on rapid atrial pacing(RAP). Methods New Zealand white rabbits were randomly divided into normal control group, normal serum control group, Zhigancao Decoction medica-ted serum group and water decoction group, 8 in each group.After the establishment of an atrial fibrillation rabbit model, the field ac-tion potential duration ( fAPD) of the right atrial appendage ( RAA ) tissue was measured and the effections of Zhigancao Decoction medicated serum and water decoction on the fAPD of RAA were observed. Results The successful modeling of rapid atrial pacing induced atrial fibrillation in rabbits contributed to the significant shortening of fAPD 12 h after pacing compared to that before pacing ([174.30 ±1.36]ms vs[162.48 ±0.88]ms, P<0.05).After giving 10%~25% Zhigancao Decoction medicated serum and water decoction, the fAPDs of RAA tissue in rabbits with atrial fibrillation were prolonged, which represented positive dose-response relation-ship.The fAPDs of the rabbits given serum containing 10%, 15%, 20%and 25%Zhigancao Decoction were respectively (170.81 ± 0.61)ms, (171.00 ±0.46)ms, (179.08 ±0.67)ms, (179.76 ±2.26)ms, which were longer than those of water decoction group ([163.82 ±0.780]ms, [163.66 ±0.95]ms, [174.06 ±1.32]ms, [176.84 ±1.19]ms), and the difference was statistically sig-nificant (P<0.05). Conclusion The fAPD can be taken as one index of cardiac electrophysiological change, and 10%~25%Zh-igancao Decoction medicated serum can lead to fAPD extension in rabbit model of atrial fibrillation, which might be the electrophysio-logical mechanism of anti-atrial fibrillation.