What is a rapid heartbeat?
A rapid heartbeat, or 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 the atria and the two lower chambers are the 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.
What are the different types of rapid heartbeats?
A rapid heartbeat (tachycardia) is a type of cardiac arrhythmia. There are different types of rapid cardiac arrhythmias, including:
- 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.
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 pumping blood effectively enough to produce a strong pulse.
If you are exercising and are in general good health, you might have a fast pulse and feel mildly short of breath during exertion. Normally, the rapid heartbeat and shortness of breath go away quickly after you slow down or stop your workout.
Serious symptoms that might indicate a life-threatening condition
A rapid heartbeat (cardiac arrhythmia) may occur with other symptoms that can indicate a serious or life-threatening condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have a rapid heartbeat associated with any of the following symptoms:
- Change in level of consciousness or alertness, such as passing out (fainting) or unresponsiveness
- Change in mental status or sudden behavior change, such as confusion, delirium, lethargy, hallucinations or delusions
- Pallor (very pale or gray skin and lips) or cyanosis (bluish discoloration of the lips, nails or skin)
- Rapid, irregular or weak pulse
- Respiratory or breathing problems, such as shortness of breath, difficulty breathing, labored breathing, wheezing, not breathing, or choking
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:
- Excessive alcohol use
- Medication side effect
- Stress, anxiety, and anxiety disorders
Serious or life-threatening causes of a rapid heartbeat
In some cases, a rapid heartbeat may be caused by a serious or life-threatening condition, such as:
- Cardiovascular disease, including coronary artery disease (CAD), abnormal heart valve function, congenital heart disease, hypertension, and heart failure
- Hyperthyroidism (overactive thyroid)
- Street drugs, such as cocaine, crack, methamphetamine and LSD
What are the potential complications of a rapid heartbeat?
Complications of a rapid heartbeat can be serious and life threatening. Failure to seek treatment can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan you and your health care professional design specifically for you to reduce the risk of potential complications including:
- Heart failure
- Ventricular fibrillation and cardiac arrest