Trifascicular Block: Difference between revisions
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==Background== | ==Background== | ||
*First degree AV block, right bundle branch block, and left anterior hemiblock | |||
*Conduction disease of all three fascicles: fight bundle branch, and left posterior and left anterior fascicles | *Conduction disease of all three fascicles: fight bundle branch, and left posterior and left anterior fascicles | ||
*Trifascicular blocks can deteriorate into high grade blocks | *Trifascicular blocks can deteriorate into high grade blocks | ||
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===Diagnosis=== | ===Diagnosis=== | ||
*Prolongation of the PR interval (first degree AV block) AND | |||
**Right bundle branch block AND | |||
**Either left anterior fascicular block or left posterior fascicular block | |||
*'''ECG will show more atrial complexes than ventricular complex indicating high grade heart block''' | *'''ECG will show more atrial complexes than ventricular complex indicating high grade heart block''' | ||
*'''Right budle branch block + extreme left axis deviation (left anterior fascicular block) + atrioventricular heart block''' | *'''Right budle branch block + extreme left axis deviation (left anterior fascicular block) + atrioventricular heart block''' | ||
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==See Also== | ==See Also== | ||
*[[Heart block]] | |||
==External Links== | ==External Links== | ||
Latest revision as of 15:31, 21 December 2020
Background
- First degree AV block, right bundle branch block, and left anterior hemiblock
- Conduction disease of all three fascicles: fight bundle branch, and left posterior and left anterior fascicles
- Trifascicular blocks can deteriorate into high grade blocks
Clinical Features
- ECG will show a bifascicular block and a prolonged PR interval
Differential Diagnosis
Differential includes ischemic events, electrolyte abnormalities, and medication overdoses in addition to rheumatologic conditions[1][2]
- Anterior MI
- Rheumatic fever
- Myocarditis
- Lyme disease
- Lenegre's disease
- Lev's disease
- SLE
- Systemic sclerosis
- Amyloidosis
- Hemochromatosis
- Sarcoidosis
- Hyperkalemia
- Toxicology
AV blocks
- First degree AV block
- Second degree
- Third degree AV block
- AV dissociation without complete heart block
Bundle and Fascicular Blocks
- Right Bundle Branch Block
- Left Bundle Branch Block
- Left Anterior Fascicular Block
- Left Posterior Fascicular Block
- Trifascicular Block
Premature Beats
Evaluation
Workup
Diagnosis
- Prolongation of the PR interval (first degree AV block) AND
- Right bundle branch block AND
- Either left anterior fascicular block or left posterior fascicular block
- ECG will show more atrial complexes than ventricular complex indicating high grade heart block
- Right budle branch block + extreme left axis deviation (left anterior fascicular block) + atrioventricular heart block
Management
- If symptomatic, standard ACLS guidelines for symptomatic bradycardia to include[3]
- Atropine 0.5mg IV q3-5min PRN total dose of 3mg
- Transcutaneous pacing, followed by transvenous pacing
- Dopamine IV consider for low BP 3mcg/kg/minute titrate up to 20 mcg/kg/minute
- Dobutamine IV consider for heart failure at 5mcg/kg/minute titrate up to 20mcg/kg/minute if needed for HR and BP augmentation
- Treat underlying etiology
- Avoid AV nodal blocking agents (e.g. β-blockers)
Disposition
- Symptomatic patients should be admitted for monitoring and evaluation for a permanent pacemaker
- Cardiology consult
See Also
External Links
References
- ↑ Hampton, JR. The ECG in Practice (5th edition), Churchill Livingstone 2008.
- ↑ Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.
- ↑ Sovari AA et al. Second-Degree Atrioventricular Block Treatment & Management. eMedicine. Apr 28, 2014. http://emedicine.medscape.com/article/161919-treatment#showall.