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][2]). However this is often exceeded during vigorous exercise and has a large inter-individual variation.

Appropiate sinustachycardia can result from: [3]

• exercise
• anxiety
• alcohol / caffeine use
• drugs (e.g. beta-agonists like dobutamine)

The following disease states can result in sinustachycardia:

• fever
• hypotension
• hypoxia
• congestive heart failure
• bleeding
• anemia
• hyperthyroidism
• cardiomyopathy (with reduced left ventricular function and compensatory tachycardia)
• myocarditis

Inappropiate sinustachycardia is rare and 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. Tanaka H, Monahan KD, and Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001 Jan;37(1):153-6. DOI:10.1016/s0735-1097(00)01054-8 |

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

   online. 2 May 2002

3. ISBN:9780721686974