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Last Updated: Mar 1, 2019


Tachycardia is an abnormally fast heart rate. In adults, the heart normally beats 60-100 times per minute. A heart rate greater than 100 beats per minute is termed tachycardia.

Tachycardia may occur in children as well as adults. In newborns and infants, tachycardia is defined as a heart rate greater than 150 beats per minute.

There are numerous causes of tachycardia and the condition is very common. Although some forms are harmless, others are potentially lethal.

Basic heart functions

The heart comprises four chambers: two upper chambers (atria) and two lower chambers (ventricles). The heart’s natural pacemaker, the sinoatrial node (SA node), is a tiny collection of cells located in the right atrium that produces each heartbeat.

The SA node generates the electrical signals that control the speed (heart rate) and pattern (rhythm) of the heartbeats. These impulses cause the atria to contract and pump blood into the ventricles. The SA node also sends electrical impulses to another collection of cells, the atrioventricular node (AV node). The AV node conducts the impulses down an electrical pathway to the ventricles, which contract and pump blood out of the heart to the lungs and the rest of the body.

Any type of abnormal heart rate or rhythm is termed an arrhythmia. Tachycardia is a type of arrhythmia where the electrical signals controlling the heart travel across the heart faster than normal, triggering the heart to beat too rapidly.

Types and Causes of Tachycardia

Numerous conditions can cause tachycardia. The severity of these problems can range from benign to life threatening. Common causes include:

Types of tachycardia

Symptoms of Tachycardia

Certain non-life-threatening types of tachycardia evoke no apparent symptoms. However, more deleterious forms interfere with the heart’s pumping ability, resulting in a number of serious events.

Common symptoms

Complications of tachycardia


When a patient’s symptoms and physical examination suggest an arrhythmia, a physician performs tests to diagnose the disorder and assess for the presence of underlying diseases.


Treatment depends on the severity of the arrhythmia and the presence of underlying diseases.


Some forms of tachycardia are avoidable by controlling lifestyle factors that lead to heart disease. Recommendations include quitting smoking, increasing rest, and avoiding alcohol and drug abuse.


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Tina Shahian, PhD

Tina is a writer for Innerbody Research, where she has written a large body of informative guides about health conditions.


A communication specialist in life science and biotech subjects, Tina’s successful career is rooted in her ability to convey complex scientific topics to diverse audiences. Tina earned her PhD in Biochemistry from the University of California, San Francisco and her BS degree in Cell Biology from U.C. Davis. Tina Shahian’s Linkedin profile.


In her spare time, Tina enjoys drawing science-related cartoons.