Left bundle branch complete conduction block, in general, does not require treatment. If the usual ECG physical examination, all show left bundle branch conduction block, no treatment is needed. If the left bundle branch complete conduction block is new, with symptoms of panic, chest tightness and shortness of breath, and if there is a cold in about two weeks, it is important to consider whether there is viral myocarditis. Cardiac ultrasound and myocardial enzymology are recommended to confirm the diagnosis of myocarditis, and treatment for myocarditis is needed. If the patient has significant chest tightness, chest pain, and a feeling of suffocating in the precordial region, and sweating on the body, it is recommended to review the electrocardiogram dynamically, and to draw blood for cardiac enzymes and cardiac ultrasound, and to suspect myocardial infarction if there is an increase in cardiac enzymes. Emergency coronary angiography and, if necessary, stenting are recommended.