What is a rapid heartbeat?

A rapid heartbeat, also called tachycardia, is a condition in which the heart is beating fast, generally more than 100 beats per minute for an adult. A rapid heartbeat can be normal, or it can result from a disease, disorder or other harmful condition.

The heart pumps blood to the lungs and the rest of the body by contracting its four chambers. The two upper chambers are called atria and the two lower chambers are called ventricles. The sinus node, a small group of cells in your right atrium, transmits an electrical impulse through the heart, causing the atria to contract. The impulse travels through the ventricles, enabling them to contract and pump blood throughout the body. The number of times the heart beats per minute is called the heart rate. The rate of these contractions is determined by nerve impulses and hormones in the blood. The rate at which your heart beats varies continuously, rising and falling in response to many conditions and situations. For example, your heart rate will rise during strenuous activity in order to ensure that all the cells of the body receive sufficient amounts of oxygen-rich blood. The heartbeat may also become faster in response to stressful situations or when you are in pain. Your heartbeat is normally lower during periods of relaxation or sleep. The average adult resting heart rate falls within the range of 60 to 80 beats per minute.

Your heart rate is affected by many factors, including age, general physical condition, aerobic conditioning, and altitude. Infants and children normally have a more rapid heartbeat than adults. A rapid heartbeat can also be caused by many diseases, disorders and conditions, such as heart disease, congenital heart defects, and hyperthyroidism.

Treatment of an abnormally rapid heartbeat varies depending on the specific type of underlying heart rhythm, its underlying cause, your age and medical history, and other factors.

Types of rapid heartbeats

A rapid heartbeat (tachycardia) is a type of cardiac arrhythmia. There are a variety of types of rapid cardiac arrhythmias:

  • Atrial fibrillation (AF) is caused by an irregular, rapid quivering of the atria, the upper chambers of the heart. AF can result in ineffective pumping of blood, pooling of blood in the atria, and the formation of blood clots.

  • Sinus tachycardia is a rapid, regular heartbeat that is over 100 beats per minute in adults. Sinus tachycardia may be normal in many cases and occurs as a response to many common conditions, such as exercise, stress, caffeine, illness, pain, or medication side effects.

  • Supraventricular tachycardia (SVT)is an extremely rapid heart rhythm that can compromise blood flow to the body if it is not treated rapidly. While anyone can develop SVT, it is more common in children. SVT is often intermittent, meaning that it comes and goes over time. Episodes may last from several minutes to several hours.

  • Ventricular tachycardia (VT) originates in the ventricles, the lower chambers of the heart. VT is life threatening because the heart contracts before filling with enough blood, resulting in an inadequate blood flow to the brain and other parts of the body. In many cases, this rapidly leads to loss of consciousness and the need for cardiopulmonary resuscitation (CPR) and advanced life-saving measures. VT can be caused by a variety of conditions, such as heart disease.

Certain types of rapid heartbeats or cardiac arrhythmias are serious or immediately life threatening. Seek immediate medical care (call 911) if you think that you, or someone you are with, have a rapid heartbeat with dizziness, fainting, or change in alertness, chest pain, or shortness of breath.

SYMPTOMS

What other symptoms might occur with a rapid heartbeat?

A rapid heartbeat may occur with or without noticeable symptoms, which can vary depending on the underlying cause. If you know how to take your own pulse, you will generally feel a rapid pulse at the wrist with a rapid heartbeat. However, in some types of serious rapid heartbeats, such as atrial fibrillation, it may be difficult to feel and count an accurate pulse because the heart is not pumpi... Read more about rapid heartbeatsymptoms

CAUSES

What causes a rapid heartbeat?

A rapid heartbeat can be caused by a wide variety of conditions. Your heartbeat will normally speed up during exercise or physical activity and slow down during periods of rest. Sometimes a rapid heartbeat occurs for no known reason.

A rapid heartbeat can also result from certain medical conditions and other causes including:

  • Caffeine

    Read more about rapid heartbeatcauses

Medical Reviewer: Cynthia Haines, MD Last Annual Review Date: Aug 8, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Heart, Blood and Circulation