2021 ICD-10-CM Diagnosis Code I45.81

Long QT syndrome

    2016 2017 2018 2019 2020 2021 Billable/Specific Code
  • I45.81 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2021 edition of ICD-10-CM I45.81 became effective on October 1, 2020.
  • This is the American ICD-10-CM version of I45.81 - other international versions of ICD-10 I45.81 may differ.
The following code(s) above I45.81 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to I45.81:
  • I00-I99
    2021 ICD-10-CM Range I00-I99

    Diseases of the circulatory system

    Type 2 Excludes
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    • systemic connective tissue disorders (M30-M36)
    • transient cerebral ischemic attacks and related syndromes (G45.-)
    Diseases of the circulatory system
Approximate Synonyms
  • Acquired long qt syndrome
  • Acquired long qt syndrome (heart)
  • Congenital long qt syndrome
  • Congenital long qt syndrome (at birth)
  • Prolonged qt interval syndrome
  • Torsades de pointes
  • Torsades type ventricular tachycardia
Clinical Information
  • A condition that is characterized by episodes of fainting (syncope) and varying degree of ventricular arrhythmia as indicated by the prolonged qt interval. The inherited forms are caused by mutation of genes encoding cardiac ion channel proteins. The two major forms are romano-ward syndrome and jervell-lange nielsen syndrome.
  • A ventricular arrhythmia characterized by syncopal episodes and a long qt interval, sometimes leading to sudden death due to paroxysmal ventricular arrhythmia. This arrhythmia is associated with a prolongation of repolarization following depolarization of the cardiac ventricles. The prolongation of the q-t interval combined with torsades de pointes manifests as several different forms; some may be acquired or congenital; some may lead to serious arrhythmia and sudden cardiac death.
  • Prolongation of q-t interval combined with torsades de pointes and manifests as several different forms; may be acquired or congenital; may lead to serious arrhythmia and sudden cardiac death.
ICD-10-CM I45.81 is grouped within Diagnostic Related Group(s) (MS-DRG v38.0):
  • 308 Cardiac arrhythmia and conduction disorders with mcc
  • 309 Cardiac arrhythmia and conduction disorders with cc
  • 310 Cardiac arrhythmia and conduction disorders without cc/mcc

Convert I45.81 to ICD-9-CM

Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
  • 2021 (effective 10/1/2020): No change
Code annotations containing back-references to I45.81:
  • Type 1 Excludes: R94.31
    ICD-10-CM Diagnosis Code R94.31

    Abnormal electrocardiogram [ECG] [EKG]

      2016 2017 2018 2019 2020 2021 Billable/Specific Code
    Type 1 Excludes

Diagnosis Index entries containing back-references to I45.81:
  • Jervell-Lange-Nielsen syndrome I45.81
  • Long
    • QT syndrome I45.81
  • Romano-Ward I45.81 (prolonged QT interval)
  • Syndrome - see also Disease
    • Jervell-Lange-Nielsen I45.81
    • long QT I45.81
    • QT interval prolongation I45.81
    • Romano-Ward I45.81 (prolonged QT interval)

ICD-10-CM Codes Adjacent To I45.81
I45.0 Right fascicular block
I45.1 Other and unspecified right bundle-branch block
I45.10 Unspecified right bundle-branch block
I45.19 Other right bundle-branch block
I45.2 Bifascicular block
I45.3 Trifascicular block
I45.4 Nonspecific intraventricular block
I45.5 Other specified heart block
I45.6 Pre-excitation syndrome
I45.8 Other specified conduction disorders
I45.81 Long QT syndrome
I45.89 Other specified conduction disorders
I45.9 Conduction disorder, unspecified
I46 Cardiac arrest
I46.2 Cardiac arrest due to underlying cardiac condition
I46.8 Cardiac arrest due to other underlying condition
I46.9 Cardiac arrest, cause unspecified
I47 Paroxysmal tachycardia
I47.0 Re-entry ventricular arrhythmia
I47.1 Supraventricular tachycardia
I47.2 Ventricular tachycardia

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.