The prevalence of right bundle branch block in the population ranged from 1.15% to 3.19%. In a prospective study of 855 male patients followed for 30 years the prevalence of right bundle branch block in the population was 0.8% at age 50 years and 9.9% at age 77 years and 11.3% at age 80 years. The study suggests that bundle branch block is very age-related and is a marker of slowly progressive degenerative disease that can affect the myocardium. Right bundle branch block is seen in normal but less frequent individuals. It is more common in children and young adults, and incomplete right bundle branch block is more common. About 1% of normal young adults have incomplete right bundle branch block. Incomplete right bundle branch block can be seen in patients with congenital heart disease, especially in atrial septal defects, and also in ventricular septal defects with biventricular enlargement and pulmonary vein malformations; it can occur in about 1/3 of patients with mitral stenosis in rheumatic heart disease. Incomplete right bundle branch block is often seen in the following pathophysiological conditions: ① congenital cardiovascular malformations; ② some coronary artery disease and cardiomyopathy; ③ some chronic pulmonary disease with mild right ventricular hypertrophy or dilatation; ④ some healthy individuals, mostly young adults, incomplete right bundle branch block may be due to damage to the distal fibers of the right bundle branch while the septum and right ventricle are de-polarized and normal. The pathogenesis of right bundle branch conduction block: In the normal heart, the right bundle branch has about 16% longer nonstop period than the left bundle branch, and the longest nonstop period of each branch is right bundle branch > left anterior branch > left posterior branch > left septal branch. The difference in conduction velocity between the left bundle branch and the right bundle branch was within 25 ms, and the QRS waveform was normal. When the right bundle branch overstay is prolonged and the conduction velocity is 25-40ms slower than that of the left bundle branch, the QRS time frame may be slightly widened and the graphical change of partial conduction block is observed, i.e. incomplete right bundle branch block is produced. If it exceeds 40ms (mostly 40-60ms) or if the right bundle branch block is interrupted, the QRS time limit is significantly widened (time limit ≥120ms), which means complete right bundle branch block is produced. Clinical manifestations of right bundle branch conduction block: Right bundle branch conduction block itself does not produce obvious hemodynamic abnormalities, so it is often asymptomatic clinically. If symptoms are present, they are usually symptoms of the primary disease. The diagnosis of right bundle branch conduction block: 1. Complete right bundle branch conduction block The QRS waves in V1 and V2 leads (or V3R and V4R) are of rSR′ type or broad and tangential R waves in V5 and V6 leads with significantly broad S waves and QRS time limit ≥0 and 12 s. The ST segment in V1 and V2 leads is depressed and the T wave is inverted; the ST segment in V5 and V6 leads is elevated and the T wave is upright. The ⅠaVL and Ⅱ leads are mostly wide and not deep S waves. 2. Incomplete right bundle branch block has the same characteristics as complete right bundle branch block except that the QRS wave time limit is <0 and 12s. The treatment of right bundle branch conduction block is mainly aimed at the treatment of the cause and the underlying disease. Because right bundle branch block itself has no significant effect on hemodynamics, it is often clinically asymptomatic and may not require special treatment. Prognosis: Right bundle branch block is very common in people without organic heart disease, and the prognosis is good in patients with intraventricular block combined with clear organic heart disease. Prevention: 1, active treatment of the cause, such as treatment of coronary artery disease, hypertension, pulmonary heart disease, myocarditis, etc., can prevent the occurrence and development of intraventricular block. 2, appropriate labor and rest, diet, regular living, and appropriate participation in physical exercise. Clinically, it is often asymptomatic and may not require special treatment.