Effects of antiarrythmic drug lidocaine on ventricular electrical activity. a computer modelling study

Lidocaine is a class Ib antiarrythmic drug that acts blocking the fast sodium current. In this work, a mathematical model of lidocaine effects has been developed. This model has been incorporated to the Luo Rudy model of guinea pig ventricular action potential and the effect of different basic cycle lengths (BCL) and concentrations of drug on the action potential characteristics has been studied. Our results show that at BCL 300 ms lidocaine reduces maximum current sodium to 7% and 39% for 10 muM and 100 muM respectively. If we increase BCL, the blockade is reduced. In addition, lidocaine reduces the maximal upstroke velocity, for BCL 500 ms the inhibition is 0.9%, 7% and 38% for 1muM, 10 muM and 100 muM respectively. This reduction depends on BCL. Conduction velocity is also affected by lidocaine, It is reduced to 4% and 23% for 10 muM and 100 muM respectively (BCL 300 ms); lower concentrations do not affect the conduction velocity