View source for Left posterior fascicular block

[[File:hemiblocks.png|thumb|His-Purkinje system and hemiblocks]]

==Criteria==
Diagnostic criteria include<ref>Surawicz B, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances. Journal of the American College of Cardiology. 2009; 53(11): 976–981.</ref>: 
#Right axis deviation (>110) 
#QRS < 120ms
#qR in III and aVF
#rS in I and aVL

===LAFB vs LPFB<ref>Mattu A and Brady WJ. ECG's for the Emergency Physician. BMJ Books. Sep 19, 2003.</ref>===
{| {{table}}
| align="center" style="background:#f0f0f0;"|'''''
| align="center" style="background:#f0f0f0;"|'''LAFB'''
| align="center" style="background:#f0f0f0;"|'''LPFB'''
|-
| Axis||Left axis deviation||Right axis deviation
|-
| I and aVL||Upright QRS||Downgoing QRS
|-
| III||Downgoing QRS||Upright QRS
|-
|}

==Significance==
*Usually associated with disease
*Isolated LPFB associated with MI<ref>Godat FJ and Gertsch M. Isolated left posterior fascicular block: a reliable marker for inferior myocardial infarction and associated severe coronary artery disease. Clin Cardiol. 1993; 16(3):220-226.</ref>
*Exclude other causes of RAD (PE, COPD, RVH, Lateral MI)

==See Also==
*[[ECG (Basics)]]
*[[Left anterior fascicular block]]

==References==
<references/>

[[Category:Cardiology]]