Modifications r waves early in the right precordial leads when a left locking occurs due to abnormal excitation current in the septum. The way of activation wave progresses in the regions engaged by the lock and the abnormal orientation of the vectors representing the electric forces in these regions, may explain the QRS-T changes observed in the electrocardiograms at the left locking ensue . Analysis of correlative changes "Waves B" or waves and blocking waves represent the normal ventricular activation clarification pathogenesis of the left blocks. The left blocks are manifested electrocardiographically as "intramural". The different lock types are to be left to the extent and magnitude of functional impairment of specialized muscle fibers in which the activation proceeds very quickly. For its size the left blocks are "partial" or "total". The duration of the ventricular complex does n...