Second degree AV block type II: Difference between revisions
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==Evaluation== | ==Evaluation== | ||
[[File:Second degree type 2.JPG|thumbnail|2nd degree AV Block Type 2 (4:3 conduction)]] | |||
[[File:Type 2 - buried p wave.JPG|thumbnail|2nd degree AVB, 2:1 conduction, LBBB with buried p-waves in t-waves]] | [[File:Type 2 - buried p wave.JPG|thumbnail|2nd degree AVB, 2:1 conduction, LBBB with buried p-waves in t-waves]] | ||
*[[ECG]] findings | ===Workup=== | ||
*[[ECG]] | |||
===Diagnosis=== | |||
*[[ECG]] findings: | |||
**Fixed PR interval for conducted QRS complexes | **Fixed PR interval for conducted QRS complexes | ||
**Intermittent non-conducted P-waves | **Intermittent non-conducted P-waves |
Revision as of 11:27, 30 March 2019
Background
- A disturbance of atrial impulse conduction, usually in the distal conduction system[1]
- 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[2]
Clinical Features
- Most patients are asymptomatic
- Symptomatic patients may present with:
Differential Diagnosis[3][4]
- Anterior MI
- Rheumatic fever
- Myocarditis
- Lyme disease
- Lenegre's disease
- Lev's disease
- SLE
- Systemic sclerosis
- Amyloidosis
- Hemachromatosis
- Sarcoidosis
- Hyperkalemia
- Toxicology
AV blocks
- First degree AV block
- Second degree
- Third degree AV block
- AV dissociation without complete 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[5]
- 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[5] 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
References
- ↑ Jones, W., and Napier, L. Atrioventricular block second-degree. Statpearls. Jan 2019
- ↑ Burns E. AV Block: 2nd degree, Mobitz II. Life in the Fast Lane. http://lifeinthefastlane.com/ecg-library/basics/mobitz-2/.
- ↑ Hampton, JR. The ECG in Practice (5th edition), Churchill Livingstone 2008.
- ↑ Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.
- ↑ 5.0 5.1 Sovari AA et al. Second-Degree Atrioventricular Block Treatment & Management. eMedicine. Apr 28, 2014. http://emedicine.medscape.com/article/161919-treatment#showall.