Sinus Tachycardia

Sinustachycardia
{{{locatieafbeelding}}}
Atrial rate	100-180 bpm
Ventricular rate	same
Regularity	{{{regularity}}}
Origin	sinus node
P-wave	positive in II, AVF
Effect of adenosine	no (can lead to temporary AV block)
Example ECG:
Example ECG2: {{{example2}}}

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

Sinustachycardia is an examples of a supraventricular rhythm. In sinustachycardia the sinus node fires between 100 and 180 beats per minute and thus faster than normally. The maximal heartrate decreases with age from around 200 bpm to 140 bpm. The maximal heartrage can be estimated by subtracting the age in years from 210. Sinustachycardia normally has a gradual start and ending. Most often sinustachycardia is caused by an increase in the body's demand for oxygen, such as during exercise, stress, infection, blood loss and hyperthyroidism. It can also express an effort of the heart to compensate for a reduced stroke volume, as occurs during cardiomyopaty.

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

This is part of: Supraventricular Rhythms