WORK GOAL: to determine the influence of Left branch block Hissa (LBBB) on: (a) the degree of heart weakness according to NYHA classification; (b) structural remodelling based on echocardiographic, and (c) functional remodelling based on EFLV i FS (echo), comparing patients with heart failure (HF) and the left branch block Hissa (LBBB) on EKG with heart failure with heart failure (HF) without the left branch block Hissa (LBBB). METHODS AND WORK: We selected group of So hospital patients with heart weakness of NYHA class II-IV with and 50 without the left branch block Hissa on EKG (LBBB). RESULTS: There was a clinical and echocardiographic evaluation of all patients and we determined their correlation related to the sex, NYHA class, structural and functional remodelling of heart cavities, EFLV, FS and survival and the number of hospitalisation in the last three years. The results where shown in a form of a table SAS 9.13 was used for statistic analysis. DISCUSSION AND CONCLUSION: LBBB is an important component of electric heart remodeling in patients with heart failure and represent an important clinic data in evaluation of patients and therapeutic approach. Because all our variables were expressed as a frequencies, chi square and Fisher exact test were used to test for potential differences. It particularly stressed the correlation of LBBB with echocardiographic movability parameters of i.v. septum and left atrium dimension (p < 0.001) while septum fibrosis (p < 0.001), paradoxal septum movability (p = 0.193) and EFLV (p < 0.001) point to a close correlation with LBBB. Other analysed parameters showed no correlation with LBBB.