Sinus Tachycardia: Sinus Node, Causes, Symptoms and Persons Prone to Manifest

The nervous system stimulates the Sinus Node to shoot faster during times of increased activity, for example, during exercise.

Sinus Tachycardia is a faster heart rate than normal. It is responsible for generating the electrical impulses that stimulate the contraction of the heart muscle.

Sinus node

This system is very carefully regulated by the brain. During normal activity, the firing rate of the Sinus Node is maintained in accordance with the body’s metabolic need.

Similarly, the Sinus Nodule triggers more slowly during periods of decreased metabolic rate, for example, during sleep.

In a healthy adult, it usually means a heart rate of more than 100 beats per minute. Babies and children have resting heart rates faster than adults, so the criteria for Sinus Tachycardia are different.

For a baby, it usually means a heart rate greater than 160-170 beats per minute. In a school-age child, Sinus Tachycardia is generally considered a heart rate of more than 120 beats per minute.


The following are situations in which Sinus Tachycardia is normal:

  • Response to the exercise (even running down a flight of stairs).
  • Emotional discomfort or anxiety
  • When you have a fever
  • When the patient is pregnant.
  • When ingesting caffeine or alcohol.
  • When smoking

There are also situations in which the rhythm is in response to an abnormal physiological condition such as the following:

  • Hypotension / Hypertension.
  • Congestive heart failure.
  • Shock.
  • In the presence of heart diseases.
  • During a heart attack .


Patients who experience Sinus Tachycardia may complain of a sensation of acceleration, palpitations, dizziness, lightheadedness or any of a variety of related symptoms. In general, no treatment is necessary in the presence of Sinus Tachycardia.

However, if Sinus Tachycardia is an inappropriate response (for example, the patient is sitting and has Sinus Tachycardia), medications may be indicated.

Most of the time, Sinus Tachycardia is not a problem but a normal physiological response of the body. The brain is very good at controlling heart rate based on the body’s metabolic needs.

During exercise, for example, the metabolic requirements of the body and muscles increase dramatically. Therefore, the brain indicates that the heart rate increases to deliver more blood and oxygen to the body.

Sinus Tachycardia is an expected finding in this context. It is also very common in other body stress responses. For example, pain, fever or emotion cause the body to release adrenaline, which increases the heart rate .

What people are more likely to manifest it?

Occasionally, it is observed that a child has a heart rate faster than expected, and then it is referred to a pediatric cardiologist to assess Sinus Tachycardia.

More commonly, a child can be referred because he has the feeling of palpitations. In this environment, the child feels that his heart beats fast.

The pediatric cardiologist then works to determine if these symptoms are due to expected Sinus Tachycardia or something else related to supraventricular tachycardia.

Primary sinus tachycardia in children is rare. Almost always, it is caused by a secondary problem outside the heart. For example, fever, infection, hypothyroidism , anemia or any other problem that increases the metabolic rate can cause Sinus Tachycardia.

Also, it can be seen in any state that produces a greater amount of adrenaline, for example, with anxiety or other emotional disorders.

Primary sinus tachycardia caused by a problem related to the heart is usually due to some type of infectious or inflammatory condition with the heart.

Inflammation of the heart muscle (myocarditis) or the lining of the heart (pericarditis) can produce Sinus Tachycardia.

This type of tachycardia itself usually does not require treatment. Again, it is usually a physiological response or normal reflection to the body and, therefore, perfectly adequate.