2009 ICD-9-CM Diagnosis Code 426.2
Left bundle branch hemiblock
- An impairment of transmission of the cardiac electrical impulse along the fibers of the left anterior fascicle. In left anterior fascicular block (LAFB) the posteroinferior regions of the left ventricular endocardium are activated abnormally before the anterosuperior left ventricular area. After emerging from the posteroinferior division of the left bundle branch, the impulse first propagates in an inferior, rightward, and usually anterior direction for a short period of time. This orientation is responsible for the small q waves in leads I and aVL and for the r waves in leads II, III, and aVF.
- An impairment of transmission of the cardiac electrical impulse along the fibers of the left anterior fascicle. In left anterior fascicular block (LAFB) the posteroinferior regions of the left ventricular endocardium are activated abnormally before the anterosuperior left ventricular area. After emerging from the posteroinferior division of the left bundle branch, the impulse first propagates in an inferior, rightward, and usually anterior direction for a short period of time. This orientation is responsible for the small Q waves in leads 1 and aVL and for the R waves in leads II, III, and aVF. (NCI)
- An impairment of transmission of the cardiac electrical impulse along the fibers of the left posterior fascicle. In pure left posterior fascicular block (LPFB), the impulse emerges from the unblocked anterosuperior division, thus producing small q waves in leads II, III, and aVF. Thereafter, the impulse moves through the electrically predominant left ventricle in an inferior and rightward direction, thus explaining the S waves in leads I and aVL as well as the R waves in leads II, III, and aVF.
- An impairment of transmission of the cardiac electrical impulse along the fibers of the left posterior fascicle. In pure left posterior fascicular block (LPFB), the impulse emerges from the unblocked anterosuperior division, thus producing small q waves in leads II, III, and aVF. Thereafter, the impulse moves through the electrically predominant left ventricle in an inferior and rightward direction, thus explaining the S waves in leads I and aVL as well as the R waves in leads II, III, and aVF. (NCI)
- Short description: LEFT BB HEMIBLOCK.
- ICD-9-CM 426.2 is a billable medical code that can be used to specify a diagnosis on a reimbursement claim.
- You are viewing the 2009 version of ICD-9-CM 426.2.
- More recent version(s) of ICD-9-CM 426.2: 2010 2011 2012 2013.
426.2 Alternative Terminology
Applies To
Convert 426.2 to ICD-10-CM 
ICD-9-CM Volume 2 Index entries containing back-references to 426.2:
bundle branch (complete) (false) (incomplete) 
with
