[The function of the left heart in blockade of the left bundle of His].

A complex Doppler echocardiographic study was performed in 134 patients with complete block of the left bundle branch, its anterior branch or with concurrence of these two types of intraventricular conduction disturbance. The authors identified 5 types of paradoxical ventricular septal motion, which were related to the specific features of intraventricular asynchronism and ventricular electric systole. Type I shows the greatest decrease in left ventricular contractility, left atrial overload and phasic destruction of left ventricular systole, which reflects the processes of depolarization and repolarization propagation in the myocardium. Type IV is characterized by the lowest number of hemodynamic abnormalities. Cardiac hemodynamics is also related to the type of intraventricular block, being the least changed in isolated anterior left bundle-branch and the most changed in concurrent anterior branch and entire left bundle-branch block.