High levels of AV block are mainly referred to as second degree type II AV block as well as third degree AV block. The characteristics of second degree II AV block mainly include the PR interval of the ECG is constant, not gradually prolonged like second degree I AV block, but every few P waves, one P wave appears to be unable to pass down, resulting in QRS wave dislodgement, this phenomenon is called Wen’s type II, also called second degree II AV block. In the other case, it is a type III AV block. In a type III AV block, the P waves and QRS waves appear separately without any obvious relationship with each other, and a large cannon sound in the precordial region can be heard on auscultation. If the patient is diagnosed with persistent second degree type II and third degree AV block, a pacemaker implantation should be actively performed to prevent accidents if there is no cause for recovery.