Atrioventricular delay is a normal physiologic phenomenon in the conduction of cardiac excitation and can occur in any normal person. The atrioventricular delay is due to the normal process of atrioventricular conduction in the heart, whereby excitatory signals traveling from the atria to the ventricles need to pass through the atrioventricular node, which has a very slow rate of conduction. AV delay is a normal physiologic phenomenon that occurs in any normal heart. The atrioventricular delay has important physiologic and pathologic significance. 1. Physiological significance: the agitation signal of the atria is immediately transmitted to the ventricles, thus ensuring the effective flow of blood from the contracted atria to the diastolic ventricles, and facilitating the filling and ejection of the heart. 2. Pathological significance: excessive atrioventricular delay due to various reasons can lead to atrioventricular block; patients with preexcitation syndrome do not have atrioventricular delay and so on. Pay attention to any discomfort and consult the doctor in time to avoid delay.