Relationship between duration of QRS complex in ECG and echocardiographic ejection fraction in patients with Left bundle Branch Block

Background&Objective: Prolongation of QRS duration particularly in Left bundle Branch Block (LBBB) is commonly associated with many cardiac diseases. Electrocardiographic study of QRS duration and electrical axis may be predictors of sever LV systolic dysfunction. Materials&Methods: In this prospective Study conducted in cardiac ward CCU and out- patient clinic of Sh. Beheshti hospital in Babol (1999-2001), 150 patients with diagnosis of LBBB divided to two groups (one QRS≥0.16 second and the other with QRS