CRT cardiac resynchronization therapy (CRT) is a treatment for heart failure patients with asynchronous ventricular contractions by means of biventricular pacing. CRT adds left ventricular pacing to the traditional dual-chamber pacing to restore synchronized ventricular contraction and reduce mitral regurgitation through multi-site pacing. Xie Ruiqin, Department of Cardiovascular Medicine, Second Hospital of Hebei Medical University For patients with heart failure with ventricular desynchronization, this treatment can improve the patient’s cardiac function, improve exercise tolerance as well as quality of life, and also has the effect of reversing left ventricular remodeling. In patients with systolic insufficiency with heart failure, those with wide QRS tend to have interventricular or intraventricular conduction disturbances and ventricular contraction with intraventricular or interventricular desynchronization. 2005 ACC/AHA published guidelines for the diagnosis and treatment of chronic heart failure in adults include CRT as a Class I indication for the treatment of patients with heart failure. The indications are as follows: cardiac resynchronization in patients with complete left bundle branch block in sinus rhythm with cardiac desynchronization and QRS > 120 ms, unless contraindicated, with optimally treated LVEF <= 35%, cardiac function NYHA class II-IV. However, 20-30% of patients do not respond to CRT therapy, so selecting the right patient to maximize their benefit is an important issue for physicians.