I47.21 Torsades de pointes

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Use additional code

• code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Code also

• , if applicable, long QT syndrome (I45.81)

Applies from I47 Paroxysmal tachycardia

Excludes1 (never code together)

• tachycardia NOS (R00.0)
• sinoauricular tachycardia NOS (R00.0)
• sinus [sinusal] tachycardia NOS (R00.0)

Code first

• tachycardia complicating:
• abortion or ectopic or molar pregnancy (O00-O07, O08.8)
• obstetric surgery and procedures (O75.4)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 238 — Specified Heart Arrhythmias
• CMS-HCC V22: HCC 96 — Specified Heart Arrhythmias
• ESRD V24: HCC 96

MS-DRG index

Defines the logic of DRG(s) 308-310 in MDC 05.

Code annotations containing back-references to I47.21

Back-references to I47.2

• Use Additional: G90.81 Serotonin syndrome ("ventricular tachycardia (I47.2-)")
• Code First: I21.A1 Myocardial infarction type 2 ("paroxysmal tachycardia (I47.0-I47.9)")

Back-references to I47

• Code First: I5A Non-ischemic myocardial injury (non-traumatic) ("paroxysmal tachycardia (I47.-)")
• Code Also: M35.81 Multisystem inflammatory syndrome ("cardiac arrhythmia (I47-I49.-)")
• Type 2 Excludes: R00 Abnormalities of heart beat ("specified arrhythmias (I47-I49)")
• Type 1 Excludes: R00.0 Tachycardia, unspecified ("paroxysmal tachycardia (I47.-)")

Diagnosis Index entries for I47.21

• Torsades de pointes

Nearby codes

• I47.10 Supraventricular tachycardia, unspecified
• I47.11 Inappropriate sinus tachycardia, so stated
• I47.19 Other supraventricular tachycardia
• I47.2 Ventricular tachycardia
• I47.20 Ventricular tachycardia, unspecified
• I47.21 Torsades de pointes (this code)
• I47.29 Other ventricular tachycardia
• I47.9 Paroxysmal tachycardia, unspecified