The Effect of Tanshinone ⅡA on the Transmembrance Action Potential of Myocardial Cells in LQT2 Rabbit Models

Objective To determine the effect of tanshinone ⅡA on the transmembrance action potential of three layers of myocardial cells in LQT2 rabbit models. Methods Whole-cell patch clamp technique was used to record the action potential duration 90 (APD90) and the transmural dispersion of repolarization(TDR) of the epicardium, mid-myocardium and endocardium in the LQT2 rabbits. Results Of the three layers of myocardial cells, the mid-myocardium had the longest APD90 and the epicardium had the shortest APD90. The APD90 of all three layers of myocardial cells were shortened with infusion of 10 mg/mL tanshinone ⅡA. Their TDR values also reduced by the infusion. Conclusion Tanshinone ⅡA shortens APD90 and reduces TDR values.