Cicada phenomenon

Cicada phenomenon is a common electrocardiographic phenomenon of heart disease. In addition to bilateral bundle branch block, it also exists in the dual pathways of atrioventricular node, between atrioventricular accessory pathway and main pathway, and between atrial conduction bundles. The generation mechanism is interference and collision. The formation condition is that there are two anatomical or functional pathways with different refractory periods and different conduction velocities in the heart. When the basic heart rate suddenly accelerates or pre systole, Premature supraventricular activation is blocked or delayed by one of the pathways with a long effective refractory period, and also produces functional block.