Home > 2015 ICD-9-CM Diagnosis Codes > Diseases Of The Circulatory System 390-459 > Other Forms Of Heart Disease 420-429 > Conduction disorders 426-
Specific code 2015 ICD-9-CM Diagnosis Code 426.3
Other left bundle branch block
  • 2015
  • Billable Thru Sept 30/2015
  • Non-Billable On/After Oct 1/2015
  • Questionable As Admission Dx

  • ICD-9-CM 426.3 is a billable medical code that can be used to indicate a diagnosis on a reimbursement claim, however, 426.3 should only be used for claims with a date of service on or before September 30, 2015. For claims with a date of service on or after October 1, 2015, use an equivalent ICD-10-CM code (or codes).
Convert to ICD-10-CM: 426.3 converts approximately to:
  • 2015/16 ICD-10-CM I44.7 Left bundle-branch block, unspecified
Approximate Synonyms
  • Complete left bundle branch block
  • Electrocardiogram: left bundle branch block
  • Left bundle branch block
  • Left main stem bundle branch block
Clinical Information
  • An impairment of transmission of the cardiac electrical impulse along the fibers of the left main bundle branch, or both the left anterior fascicle and left posterior fascicle. This conduction disturbance is characterized by wide (greater than 0.11s) qrs complexes. The diagnostic criteria consist of prolongation of the qrs complexes (over 0.11s) with neither a q wave nor an s wave in lead v1 and in the "properly placed" v6. A wide r wave with a notch on its top ("plateau") is seen in these leads. In hearts with an electrical (and anatomic) vertical position a small q wave may be seen in avl in the absence of mi. Right chest lead v1 may or may not show an initial r wave, but the latter should be present in lead v2
  • An impairment of transmission of the cardiac electrical impulse along the fibers of the left main bundle branch, or both the left anterior fascicle and left posterior fascicle. This conduction disturbance is characterized by wide (greater than 0.11s) qrs complexes. The diagnostic criteria consist of prolongation of the qrs complexes (over 0.11s) with neither a q wave nor an s wave in lead v1 and in the properly placed v6. A wide r wave with a notch on its top (plateau) is seen in these leads. In hearts with an electrical (and anatomic) vertical position a small q wave may be seen in avl in the absence of mi. Right chest lead v1 may or may not show an initial r wave, but the latter should be present in lead v2. (nci)
Applies To
  • Left bundle branch block:
    • NOS
    • anterior fascicular with posterior fascicular
    • complete
    • main stem
ICD-9-CM Coding Information
  • 426.3 is not usually sufficient justification for admission to an acute care hospital when used a principal diagnosis.
ICD-9-CM Volume 2 Index entries containing back-references to 426.3:
  • Block
    • bundle branch (complete) (false) (incomplete) 426.50
      • bilateral 426.53
      • left (complete) (main stem) 426.3
        • with right bundle branch block 426.53
        • anterior fascicular 426.2
          • with
            • posterior fascicular block 426.3
            • right bundle branch block 426.52
        • hemiblock 426.2
        • incomplete 426.2
          • with right bundle branch block 426.53
        • posterior fascicular 426.2
          • with
            • anterior fascicular block 426.3
            • right bundle branch block 426.51
      • right 426.4
      • Wilson's type 426.4
    • heart 426.9
      • first degree (atrioventricular) 426.11
      • second degree (atrioventricular) 426.13
      • third degree (atrioventricular) 426.0
      • bundle branch (complete) (false) (incomplete) 426.50
        • bilateral 426.53
        • left (see also Block, bundle branch, left) 426.3
        • right (see also Block, bundle branch, right) 426.4
      • complete (atrioventricular) 426.0
      • congenital 746.86
      • incomplete 426.13
      • intra-atrial 426.6
      • intraventricular NEC 426.6
      • sinoatrial 426.6
      • specified type NEC 426.6
    • intraventricular (diffuse) (myofibrillar) 426.6
      • bundle branch (complete) (false) (incomplete) 426.50
        • bilateral 426.53
        • left (see also Block, bundle branch, left) 426.3
        • right (see also Block, bundle branch, right) 426.4
  • Bundle
    • branch block (complete) (false) (incomplete) 426.50
      • bilateral 426.53
      • left (see also Block, bundle branch, left) 426.3
      • right (see also Block, bundle branch, right) 426.4
  • Degeneration, degenerative
  • Sclerosis, sclerotic
 426.2 ICD9Data.com 426.4 
ICD-9-CM codes are used in medical billing and coding to describe diseases, injuries, symptoms and conditions. ICD-9-CM 426.3 is one of thousands of ICD-9-CM codes used in healthcare. Although ICD-9-CM and CPT codes are largely numeric, they differ in that CPT codes describe medical procedures and services. Can't find a code? Start at the root of ICD-9-CM, check the 2015 ICD-9-CM Index or use the search engine at the top of this page to lookup any code.
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