Second degree AV block type II

Revision as of 04:29, 25 July 2016 by Neil.m.young (talk | contribs) (Text replacement - "==Diagnosis==" to "==Evaluation==")

Background

  • Significant risk of hemodynamic instability, symptomatic bradycardia, and decompensation into Third Degree AV Block
  • Risk of asystole 35% per year[1]
2nd degree AV Block Type 2 (4:3 conduction)

Clinical Features

Differential Diagnosis[2][3]

AV blocks

Evaluation

  • 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)
2nd degree AVB, 2:1 conduction, LBBB with buried p-waves in t-waves

Management

  • Standard ACLS guidelines for bradycardia to include[4]
    • Atropine 0.5mg IV q3-5min prn
    • Transcutaneous pacing, followed by transvenous pacing
  • Treat underlying etiology
  • Avoid AV nodal blocking agents (beta blockade in myocardial infarction)

Disposition

  • Admission for pacing and monitoring
  • Subsequent permanent pacemaker
  • 2:1[4] and 3:1 blocks

See Also

AV blocks

References

  1. Burns E. AV Block: 2nd degree, Mobitz II. Life in the Fast Lane. http://lifeinthefastlane.com/ecg-library/basics/mobitz-2/.
  2. Hampton, JR. The ECG in Practice (5th edition), Churchill Livingstone 2008.
  3. Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.
  4. 4.0 4.1 Sovari AA et al. Second-Degree Atrioventricular Block Treatment & Management. eMedicine. Apr 28, 2014. http://emedicine.medscape.com/article/161919-treatment#showall.