Alternative Name for High-Grade AV Block
High-grade AV block is also called "advanced second-degree AV block." 1
Terminology and Definition
Advanced second-degree AV block is the standard alternative terminology used in major cardiology guidelines, including the ACC/AHA/HRS guidelines for device-based therapy 1
This term specifically refers to blockage of two or more consecutive P waves (but not all P waves, which would be complete/third-degree block) 1
High-grade AV block represents a more severe form of conduction disease than typical Mobitz Type I or Type II second-degree block, where only single P waves are blocked 1
Clinical Distinction from Other AV Blocks
Complete heart block (third-degree AV block) is a separate entity where no atrial impulses reach the ventricles, whereas high-grade/advanced second-degree block still has some conducted beats 1, 2
The guidelines consistently group "third-degree and advanced second-degree AV block" together for treatment recommendations, reflecting their similar clinical significance and management 1
Clinical Significance
Both terms carry the same clinical implications: these patients require permanent pacemaker implantation when symptomatic (Class I indication) or even when asymptomatic with certain high-risk features 1
High-grade/advanced AV block is associated with increased mortality risk, particularly in the setting of acute myocardial infarction, where it occurs in approximately 1.5% of STEMI patients undergoing primary PCI 3
The prognosis and management approach for high-grade AV block mirrors that of complete heart block, distinguishing it from lower-grade conduction abnormalities 1