Objective: To determine the effect of tanshinone II A 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 II A. Their TDR values also reduced by the infusion.
Conclusion: Tanshinone II A shortens APD90 and reduces TDR values.