High Grade AV Block

High-grade AV block, also known as advanced heart block, is a form of third-degree heart block.

This occurs when AV dissociation is present; however, intermittently some sinus node action potentials (P waves) are randomly conducted to the ventricles. This is different than “complete heart block," another form of third-degree heart block, where no sinus node activity conducts through the AV node to the ventricles at all.

Treatment of high-grade AV block is permanent pacemaker implantation.