Inappropriate sinus tachycardia

Europace. 2019 Feb 1;21(2):194-207. doi: 10.1093/europace/euy128.


Inappropriate sinus tachycardia (IST) is a clinical syndrome, oftentimes debilitating, defined by fast sinus rates (>100 b.p.m. at rest or >90 b.p.m. on average over 24 h and not due to underlying causes) associated with symptoms that may include palpitations, as described in some guidelines and consensus documents. While heart rates may vary by patient, especially based upon gender and age, some individuals experience sinus tachycardia or persistent fast sinus rates with no symptoms; these individuals would not necessarily be considered to have the syndrome of IST. Various explanations for IST have been considered but a definitive common mechanism is not yet known; the true aetiology may be multifactorial. A thorough evaluation of secondary causes of tachycardia is required in the work-up of all cases and if found, must be treated before a diagnosis of IST can be made. Finally, effective treatments vary but can include ivabradine, beta-blockers, or calcium channel antagonists; ablation is seldom advised.

Publication types

  • Review

MeSH terms

  • Ablation Techniques
  • Adult
  • Age Factors
  • Animals
  • Anti-Arrhythmia Agents / therapeutic use
  • Female
  • Heart Rate* / drug effects
  • Humans
  • Male
  • Middle Aged
  • Risk Factors
  • Sex Factors
  • Sinoatrial Node / drug effects
  • Sinoatrial Node / physiopathology*
  • Sinoatrial Node / surgery
  • Syndrome
  • Tachycardia, Sinus / diagnosis
  • Tachycardia, Sinus / etiology
  • Tachycardia, Sinus / physiopathology*
  • Tachycardia, Sinus / therapy
  • Time Factors
  • Treatment Outcome


  • Anti-Arrhythmia Agents