[Modern concepts of the ECG changes in branch block of the bundle of His and of the ramifications of the left branch].

The author reports on the modern conceptions on the structure of the interventricular conduction system, classification and the diagnostic signs of the block of pedicles of His bundle and the branches of the left pedicle. ECG signs of the block of the left and right pedicles of His' bundle are described. ECG changes in the block of the anterior and posterior branches of the left pedicle are given. The combined types of blocks are discussed: block of the right pedicle of His' bundle and the anterior branch of the left pedicle, block of the right pedicle and the posterior branch of the left pedicle. It is pointed out that the combination of the block of the left pedicle and of the anterior branch of the left pedicle is possible. The symptoms of a bilateral and three bundle blocks are given. A focal intraventricular and non-specific intraventricular blocks, and masked block of the pedicle are described. The intraventricular blocks are subdivided into complete and incomplete and their ECG characteristics are given.