3rd degree and advanced 2nd degree AV block at any anatomic level associated with bradycardia with symptoms (including heart failure) or ventricular arrhythmia presumed to be due to AV block

Class I

3rd degree and advanced 2nd degree AV block at any anatomic level associated with arrhythmias and other medical conditions that require drug therapy that results in symptomatic bradycardia

Class I

3rd degree and advanced 2nd degree AV block at any anatomic level in awake, symptom-free patients in sinus rhythm, with documented periods of asystole greater than or equal to 3.0 s, or any escape rate <40 bpm, or with an escape rhythm that is below AV node

Class I

3rd degree and advanced 2nd degree AV block at any anatomic level in awake, symptom-free patients with atrial fibrillation and bradycardia with one or more pauses of at least 5 s or longer

Class I

3rd degree and advanced 2nd degree AV block at any anatomic level associated with postoperative AV block that is not expected to resolve after cardiac surgery

Class I

3rd degree and advanced 2nd degree AV block at any anatomic level after catheter ablation of the AV junction

Class I

3rd degree and advanced 2nd degree AV block at any anatomic level associated with neuromuscular diseases with AV block

Class I

2nd degree AV block with associated symptomatic bradycardia regardless of type or site of block

Class I

Asymptomatic persistent 3rd degree AV block at any anatomic site with average awake ventricular rates of 40 bpm or faster if cardiomegaly or LV dysfunction is present or if site of block is below the AV node

Class I

2nd or 3rd degree AV block during exercise in the absence of myocardial ischemia

Class I

Persistent 3rd degree AV block with an escape rate greater than 40 bpm in asymptomatic adult patients without cardiomegaly

Class IIa

Asymptomatic 2nd degree AV block at intra- or infra- His levels found at electrophysiological study

Class IIa

1st or 2nd degree AV block with symptoms similar to those of pacemaker syndrome or hemodynamic compromise

Class IIa

Asymptomatic type II 2nd degree AV block with a narrow QRS

Class IIa

Neuromuscular diseases with any degree of AV block (including 1st degree AV block), with or without symptoms

Class IIb

AV block in the setting of drug use and/or drug toxicity when the block is expected to recur even after the drug is withdrawn

Class IIb

Advanced 2nd degree AV block or intermittent 3rd degree AV block

Class I

Type II second-degree AV block

Class I

Alternating bundle-branch block

Class I

Syncope not demonstrated to be due to AV block when other likely causes have been excluded, specifically ventricular tachycardia

Class IIa

Incidental finding at electrophysiological study of a markedly prolonged HV interval >100 ms in asymptomatic patients

Class IIa

Incidental finding at electrophysiological study of pacing-induced infra-His block that is not physiological.

Class IIa

Neuromuscular diseases with bifascicular block or any fascicular block, with or without symptoms