What is Tachycardia?

What is tachycardia?

Tachycardia is a condition in which the heart rate is over 100 beats per minute. Tachycardia or palpitations is a symptom, not a disease. Many irregular heart rhythms, known as arrhythmias, can cause tachycardia or palpitations. In this type of palpitations, treating the underlying arrhythmia can stop the palpitations. The heart rate may also increase in response to stress, caffeine intake, excitement, fear or other non-cardiac diseases.

For a better understanding, you can look at the classification of tachycardia.

Types of tachycardia
Types of tachycardia

What are the types of tachycardia?

The arrhythmias that cause tachycardia can be classified as sinus tachycardia, supraventricular tachycardias, atrial fibrillation, a form of svt, and ventricular tachycardias.

What is sinus tachycardia?

Sinus tachycardia is when the rate of the focus that initiates the electrical impulse in the heart is greater than 100 per minute. Sinus tachycardia is an acceleration that occurs when walking, running, getting angry or excited. It is usually caused by stress or exercise. When these conditions are over, the heart rate slows down again. Stimulants such as excessive tea and coffee can speed up the sinus node and you may feel palpitations. Sometimes stimulants such as illicit drugs, cocaine, methamphetamine, marijuana can cause sinus tachycardia. They can also cause more dangerous arrhythmias.

Other diseases can also cause sinus tachycardia. Such as fever, anaemia, overactive thyroid.

In so-called inappropriate sinus tachycardia, the sinus node is constantly working fast for no reason. During the day the rate is over 100 and the 24-hour average is over 90. The rate returns to normal during sleep. It greatly impairs quality of life. You should contact your doctor for medical help.


Rhythm disorders originating from the atria causing the heart to accelerate excessively are called SVT or Supraventricular tachycardia. It is usually a regular palpitation. In other words, when it starts, the patient notices this palpitation that starts suddenly and continues regularly. It is terminated spontaneously or by giving medication in hospital. There are various subtypes.

  • AVNRT (AV Nodal Re-Entran Tachycardia)
  • AVRT (Atrioventricular Re-Entran Tachycardia)
  • AT (Atrial tachycardia)
  • Atrial Flutter
  • Nodal Tachycardia

Atrial Fibrillation or AFib

Atrial fibrillation is also a type of SVT but is classified separately because it is chaotic and irregular. In this rhythm disorder, the atria work very fast and irregularly. The transition to the ventricles is also irregular, so the pulse is also irregular. It increases the risk of stroke to varying degrees, depending on the person’s age and risk factors such as diabetes, hypertension, heart failure and coronary artery disease. It may also pose a risk of heart failure.

Ventricular Tachycardia

You can find detailed information about ventricular tachycardia here.

What are the Symptoms of Tachycardia?

Patients feel heart palpitations in tachycardia. Along with palpitations, complaints of dizziness, fainting, feeling faint, chest pain, difficulty breathing may occur. These usually indicate more risky arrhythmias. Pulse irregularity may also be a sign of arrhythmia.

What Causes Tachycardia?

When we run, get excited, with emotional stresses (psychologically), your heart rate increases in a completely normal way. This is not a disease but something that should happen. If you have a fever, your pulse rate increases. If your temperature rises by 1 degree, your pulse rate increases by 10. If your thyroid is overactive, if you have anaemia, your pulse rate increases. These are also a response of the heart to other diseases.

Tachycardia can also be caused by abnormalities in the electrical system of the heart. These are called heart rhythm disorders or arrhythmias. They can originate in the atria or ventricles. Tachycardias (palpitations) due to arrhythmias can lead to heart failure, stroke and sometimes death, as well as impairing quality of life. Therefore, you should pay attention to palpitations and consult your physician.

Severe arrhythmias can occur if you have a structural heart disease (e.g. heart failure, previous heart attack, valve disease) or congenital electrical abnormalities of the heart (such as Brugada syndrome, Long or Short QT syndrome, WPW syndrome).

Tachycardia Treatment?

Tachycardia treatment is aimed at correcting the cause of tachycardia. If there is another disease causing tachycardia (overactive thyroid, anaemia, etc.), tachycardia may be relieved by correcting that disease. If the cause of the tachycardia is a rhythm disorder, the rhythm disorder should be terminated with drug treatment or ablation. Ablation is performed with a 70-99% success rate in many rhythm disorders.

Drugs to be used in tachycardia vary depending on the disease. Drugs can be used to reduce the heart rate or to prevent the occurrence of arrhythmia.

AVNRT (AV Nodal Re-Entran Tachycardia) ECG

Reference: Tachycardia

Update: Feb 14, 2024

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Picture of Prof. Dr. Taylan Akgün
Prof. Dr. Taylan Akgün

He is a cardiologist specialised in the diagnosis and treatment of heart rhythm problems (ablation), pacemaker procedures.
He works in Istanbul province.

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