Sinus Tachycardia

This is part of: Supraventricular Rhythms

Sinustachycardia is sinus rhythm with a rate of > 100bpm.

The maximal heart rate is considered to be 220/min minus the age (or more precisely 207-0.7xAge [1]). However this is often exceeded during vigorous exercise and has a large inter-individual variation.

Appropiate sinustachycardia can result from: [2]

• exercise
• anxiety
• alcohol / caffeine use
• drugs (e.g. beta-agonists like dobutamine)
• fever
• hypotension
• hypoxia
• congestive heart failure
• bleeding
• anemia
• hyperthyroidism
• cardiomyopathy
• myocarditis

Inappropiate sinustachycardia is characterized by tachycardia at rest and exaggerated acceleration of the heart during physiologic stress. The mechanism leading to an exaggerated response of the sinus node to minimal physiologic stress is incompletely understood.

References

1. Robergs and Landwehr. The Surprising History of the “HRmax=220-age” Equation. Journal of Exercise Physiology

   online. 2 May 2002

2. ISBN:9780721686974