View source for Second degree AV block type II

==Background==
[[File:Second degree heart block.png|thumb|Types of second degree AV block]]
*A disturbance of atrial impulse conduction, usually in the distal conduction system<ref>Jones, W., and Napier, L. Atrioventricular block second-degree. Statpearls. Jan 2019</ref>
*Often associated with structural heart disease
*Significant risk of hemodynamic instability, symptomatic bradycardia, and decompensation into [[Third Degree AV Block]] and subsequent cardiac arrest
**Risk of asystole 35% per year<ref>Burns E. AV Block: 2nd degree, Mobitz II. Life in the Fast Lane. http://lifeinthefastlane.com/ecg-library/basics/mobitz-2/.</ref>

==Clinical Features==
*Most patients are asymptomatic
*Symptomatic patients may present with:
**[[Chest pain]]
**[[Hypotension]]
**[[Bradycardia]]
**[[Altered mental status]]
**[[Syncope]], [[weakness]]

==Differential Diagnosis==
{{Heart block DDX}}

==Evaluation==
{{Heart block evaluation workup}}
===Diagnosis===
*[[ECG]] findings:
**Fixed PR interval for conducted QRS complexes
**Intermittent non-conducted P-waves
**P waves march through (beware of p-waves consistently buried in T-waves)

==Management==
*If symptomatic, standard [[ACLS guidelines for symptomatic bradycardia]] includes<ref name="Sovari">Sovari AA et al. Second-Degree Atrioventricular Block Treatment & Management. eMedicine. Apr 28, 2014. http://emedicine.medscape.com/article/161919-treatment#showall.</ref>
**[[Atropine]] 0.5mg IV q3-5min PRN
**[[Transcutaneous pacing]], followed by [[transvenous pacing]]
*Treat underlying etiology
*Avoid AV nodal blocking agents (e.g. [[β-blockers]])

==Disposition==
*Admission for pacing and monitoring
*Subsequent permanent pacemaker
*2:1<ref name="Sovari" /> and 3:1 blocks
**May be unable to determine if [[Second Degree AV Block Type I]] or type II
**Admit to cardiology and assume type II

==See Also==
*[[AV blocks]]

==References==
<references/>

[[Category:Cardiology]]