Sinus tachycardia: signs, symptoms, and causes

2021-08-28 08:44 PM

Tachycardia alone is a very nonspecific symptom. Its symptomatic value depends on the clinical circumstances. It has limited value in predicting volume loss. If combined with other symptoms, it is valuable in predicting pneumonia

Description

The heart rate is more than 100 beats/min.

Flow chart Tachycardia mechanism 

Cause

Sinus tachycardia is associated with many different conditions. Maybe a normal physiological response or the result of a pathological response. Those conditions include:

Popular

Do exercise.

Concerned.

Pain.

Infection.

Volume reduction.

Anemia.

Decreased cardiac output (heart failure).

Sinus rhythm dysfunction.

Pulmonary embolism.

Hyperthyroidism.

Stimulants and drugs (eg, caffeine, beta-2 agonists, cocaine).

Reduce oxygen.

Heart attack.

Less popular

Pheochromocytoma.

Mechanism

A clear understanding of the mechanism of each cause of tachycardia has not been established. Most of the pathways in cases of sinus tachycardia are by sympathetic activation and/or catecholamine release. This is typical in cases of anxiety, fear, and hypovolemia, but is not typical in cases of pheochromocytoma or drugs that release (or cause the release of) catecholamines.

Mechanism in Hyperthyroidism

The mechanism of tachycardia in hyperthyroidism is unique and results from elevated T3 levels.

T3 is both genomic (regulated and expressed by a single gene) and non-genomic in affecting production and altering the activity of myofibril protein, endoplasmic reticulum, ATPase, and Na, K, and Ca channel. The end result is increased contractility, increased heart rate, and increased cardiac output.

Significance

Tachycardia alone is a very nonspecific symptom. Its symptomatic value depends on the clinical circumstances. However, studies show that:

It has limited value in predicting volume loss.

If combined with other symptoms, it is valuable in predicting pneumonia.

In trauma, infectious pneumonia, and myocardial infarction, tachycardia has prognostic value and predictive value for increased mortality.

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Tachycardia: abnormal sinus rhythm

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Complicated pathology of sinusitis