Abstract:Objective To analyze and discuss ECG feature and differential diagnosis and treatment of complete pre-excitation syndrome. Methods Electrocardiogram characteristics and QRS morphologies of 40 patients with complete pre-excitation syndrome were analyzed. Results Twenty five cases with atrial fibrillation(AF),8 of which were accompanied by organic heart disease,sinus rhythm was corrected by using propafenone or amiodarone administration and direct electrical cardioversion treatment respectively; 2 cases with atrial flutter occurred in the AF termination,5 cases with reverse type atrioventricular reentrant tachycardia.10 cases with complete pre-excitation syndrome during sinus rhythm,2 of which with one degree atrioventricular block,2 cases with two degree atrioventricular block,5 cases with three degree atrioventricular block,one with complete double bundle branch block,pacemaker implantation was performed in 7. Conclusion Complete pre-excitation syndrome morphologies,typical pre-excitation syndrome and various combinations of normal QRS waves were present when AF occurred. Complete pre-excitation syndrome was present when one degree or three degree atrioventricular block occurred in the normal atrioventricular pathway.