[Different sensitivities of two mechanisms of excitation waves in heart tissue to anti-arrhythmia agents--blockers of fast sodium currents].

In experiments with rabbit ventricular tissue sensitivity of two kinds of spiral wave sources of excitation to fast sodium current inhibition was compared. These spiral wave sources were circulation in a ring around an obstacle and circulation in tissue without an obstacle (reverberator). It was observed that after application of antiarrhythmic drugs lidocaine or mexiletine there was a prominent growth of cycle length of reverberator during first few seconds of circulation and a little change of cycle length for the circus movement around obstacle. It is proposed that different sensitivity of both kinds of spiral wave sources to antiarrhythmic drugs can be used for their distinguishing in clinical practice.