Tachycardia is a common type of heart rhythm disorder (arrhythmia) in which the heart beats faster than normal while at rest.
It's normal for your heart rate to rise during exercise or as a physiological response to stress, trauma or illness (sinus tachycardia). But in tachycardia (tak-ih-KAHR-dee-uh), the heart beats faster than normal in the upper or lower chambers of the heart or both while at rest.
Your heart rate is controlled by electrical signals sent across heart tissues. Tachycardia occurs when an abnormality in the heart produces rapid electrical signals that quicken the heart rate, which is normally about 60 to 100 beats a minute at rest.
In some cases, tachycardia may cause no symptoms or complications. But if left untreated, tachycardia can disrupt normal heart function and lead to serious complications, including:
- Heart failure
- Sudden cardiac arrest or death
Treatments, such as drugs, medical procedures or surgery, may help control a rapid heartbeat or manage other conditions contributing to tachycardia.
Types of tachycardia
There are many different types of abnormal tachycardia. They're classified according to the origin and cause of the abnormally fast heartbeat. Common types of tachycardia include:
Atrial fibrillation. Atrial fibrillation is a rapid heart rate caused by chaotic, irregular electrical impulses in the upper chambers of the heart (atria). These signals result in rapid, uncoordinated, weak contractions of the atria.
Atrial fibrillation may be temporary, but some episodes won't end unless treated.
Atrial fibrillation is the most common type of tachycardia. Most people with atrial fibrillation have some structural abnormalities of the heart related to underlying conditions such as heart disease or high blood pressure. Other factors that may contribute to atrial fibrillation include a heart valve disorder, hyperthyroidism or heavy alcohol use.
Atrial flutter. In atrial flutter, the heart's atria beat very fast but at a regular rate. The fast rate results in weak contractions of the atria.
Atrial flutter is caused by irregular circuitry within the atria. Episodes of atrial flutter may resolve themselves or may require treatment.
People who experience atrial flutter also often experience atrial fibrillation at other times.
- Supraventricular tachycardia (SVT). Supraventricular tachycardia is an abnormally fast heartbeat that originates somewhere above the ventricles. It's caused by abnormal circuitry in the heart that is usually present at birth and creates a loop of overlapping signals.
Ventricular tachycardia. Ventricular tachycardia is a rapid heart rate that originates with abnormal electrical signals in the lower chambers of the heart (ventricles). The rapid heart rate doesn't allow the ventricles to fill and contract efficiently to pump enough blood to the body.
Ventricular tachycardia episodes may be brief and last only a couple of seconds without causing harm. But episodes lasting more than a few seconds can become a life-threatening medical emergency.
Ventricular fibrillation. Ventricular fibrillation occurs when rapid, chaotic electrical impulses cause the ventricles to quiver ineffectively instead of pumping necessary blood to the body. This can be fatal if the heart isn't restored to a normal rhythm within minutes with an electric shock to the heart (defibrillation).
Ventricular fibrillation may occur during or after a heart attack. Most people who experience ventricular fibrillation have an underlying heart disease or have experienced serious trauma, such as being struck by lightning.
When your heart is beating too fast, it may not pump blood effectively to the rest of your body. This can deprive your organs and tissues of oxygen and can cause the following tachycardia-related signs and symptoms:
- Shortness of breath
- Rapid pulse rate
- Heart palpitations a racing, uncomfortable or irregular heartbeat or a sensation of "flopping" in the chest
- Chest pain
- Fainting (syncope)
Some people with tachycardia have no symptoms, and the condition is only discovered during a physical examination or with a heart-monitoring test called an electrocardiogram.
When to see a doctor
A number of conditions can cause a rapid heart rate and tachycardia symptoms. It's important to get a prompt, accurate diagnosis and appropriate care. See your doctor if you or your child experiences any tachycardia symptoms.
If you faint, have difficulty breathing or have chest pain lasting more than a few minutes, get emergency care, or call 911 or your local emergency number. Seek emergency care for anyone experiencing these symptoms.
Tachycardia is caused by something that disrupts the normal electrical impulses that control the rate of your heart's pumping action. Many things can cause or contribute to problems with the heart's electrical system. These include:
- Damage to heart tissues from heart disease
- Abnormal electrical pathways in the heart present at birth (congenital heart conditions, including long QT syndrome)
- Disease or congenital abnormality of the heart
- Sudden stress, such as fright
- High or low blood pressure
- Drinking too much alcohol
- Drinking too many caffeinated beverages
- Medication side effects
- Abuse of recreational drugs, such as cocaine
- Imbalance of electrolytes, mineral-related substances necessary for conducting electrical impulses
- Overactive thyroid (hyperthyroidism)
In some cases, the exact cause of tachycardia can't be determined.
The heart's electrical system
To understand the causes of heart rate or rhythm problems such as tachycardia, it helps to understand how the heart's internal electrical system works.
Your heart is made up of four chambers — two upper chambers (atria) and two lower chambers (ventricles). The rhythm of your heart is normally controlled by a natural pacemaker called the sinus node, which is located in the right atrium. The sinus node produces electrical impulses that normally start each heartbeat.
From the sinus node, electrical impulses travel across the atria, causing the atrial muscles to contract and pump blood into the ventricles.
The electrical impulses then arrive at a cluster of cells called the atrioventricular (AV) node — usually the only pathway for signals to travel from the atria to the ventricles.
The AV node slows down the electrical signal before sending it to the ventricles. This slight delay allows the ventricles to fill with blood. When electrical impulses reach the muscles of the ventricles, they contract, causing them to pump blood either to the lungs or to the rest of the body.
When anything disrupts this complex system, it can cause the heart to beat too fast (tachycardia), too slow (bradycardia) or with an irregular rhythm.
Any condition that puts a strain on the heart or damages heart tissue can increase your risk of tachycardia. Lifestyle changes or medical treatment may decrease the risk associated with the following factors:
- Heart disease
- High blood pressure
- Sleep apnea
- Overactive or underactive thyroid
- Heavy alcohol use
- Heavy caffeine use
- Use of recreational drugs
- Psychological stress or anxiety
Other risk factors
Other factors that may increase the risk of tachycardia include:
- Older age. Aging-related wear on the heart makes you more likely to develop tachycardia.
- Family. If you have a family history of tachycardia or other heart rhythm disorders, you may have an increased risk of tachycardia.
Complications of tachycardia vary in severity depending on factors such as the type of tachycardia, the rate and duration of rapid heart rate, and the existence of other heart conditions. Possible complications include:
- Blood clots that can cause a stroke or heart attack
- Inability of the heart to pump enough blood (heart failure)
- Frequent fainting spells or unconsciousness
- Sudden death, usually only associated with ventricular tachycardia or ventricular fibrillation
The most effective way to prevent tachycardia is to maintain a healthy heart and reduce your risk of developing heart disease. If you already have heart disease, monitor it and follow your treatment plan to lower your tachycardia risk.
Prevent heart disease
Treat or eliminate risk factors that may lead to heart disease. Take the following steps:
- Exercise and eat a healthy diet. Live a heart-healthy lifestyle by exercising regularly and eating a healthy, low-fat diet that's rich in fruits, vegetables and whole grains.
- Maintain a healthy weight. Being overweight increases your risk of developing heart disease.
- Keep blood pressure and cholesterol levels under control. Make lifestyle changes and take medications as prescribed to correct high blood pressure (hypertension) or high cholesterol.
- Stop smoking. If you smoke and can't quit on your own, talk to your doctor about strategies or programs to help you break a smoking habit.
- Drink in moderation. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger. For some conditions it's recommended that you completely avoid alcohol. Ask your doctor for advice specific to your condition.
- Don't use recreational drugs. Don't use stimulants, such as cocaine. Talk to your doctor about an appropriate program for you if you need help ending recreational drug use.
- Use over-the-counter medications with caution. Some cold and cough medications contain stimulants that may trigger a rapid heartbeat. Ask your doctor which medications you need to avoid.
- Limit caffeine. If you drink caffeinated beverages, do so in moderation (no more than one to two beverages daily).
- Control stress. Avoid unnecessary stress and learn coping techniques to handle normal stress in a healthy way.
- Go to scheduled checkups. Have regular physical exams and report any signs or symptoms to your doctor.
Monitor and treat existing heart disease
If you already have heart disease, you can take steps to lower your risk of developing tachycardia or another arrhythmia:
- Follow the plan. Be sure you understand your treatment plan, and take all medications as prescribed.
- Report changes immediately. If your symptoms change or get worse or you develop new symptoms, tell your doctor immediately.
To diagnose your condition and determine the specific type of tachycardia, your doctor will evaluate your symptoms, conduct a thorough physical examination, and ask you about your health habits and medical history.
Several heart tests also may be necessary to diagnose tachycardia.
An electrocardiogram, also called an ECG or EKG, is the most common tool used to diagnose tachycardia. It's a painless test that detects and records your heart's electrical activity using small sensors (electrodes) attached to your chest and arms.
An ECG records the timing and strength of electrical signals as they travel through your heart. Your doctor can look for patterns among these signals to determine what kind of tachycardia you have and how abnormalities in the heart may be contributing to a fast heart rate.
Your doctor may also ask you to use portable ECG devices at home to provide more information about your heart rate. These devices include:
Holter monitor. This portable ECG device is carried in your pocket or worn on a belt or shoulder strap. It records your heart's activity for an entire 24-hour period, which provides your doctor with a prolonged look at your heart rhythms.
Your doctor will likely ask you to keep a diary during the same 24 hours. You'll describe any symptoms you experience and record the time they occur.
Event monitor. This portable ECG device is intended to monitor your heart activity over a few weeks to a few months. You wear it all day, but it records only at certain times for a few minutes at a time.
With many event monitors, you activate them by pushing a button when you experience symptoms of a fast heart rate. Other monitors automatically sense abnormal heart rhythms and then start recording. These monitors allow your doctor to look at your heart rhythm at the time of your symptoms.
Your doctor may recommend an electrophysiological test to confirm the diagnosis or to pinpoint the location of problems in your heart's circuitry.
During this test, a doctor inserts thin, flexible tubes (catheters) tipped with electrodes into your groin, arm or neck and guides them through your blood vessels to various spots in your heart. Once in place, the electrodes can precisely map the spread of electrical impulses during each beat and identify abnormalities in your circuitry.
Imaging of the heart may be performed to determine if structural abnormalities are affecting blood flow and contributing to tachycardia.
Types of cardiac imaging used to diagnose tachycardia include:
- Echocardiogram (echo). An echocardiogram creates a moving picture of your heart using sound waves. An echo can identify areas of poor blood flow, abnormal heart valves and heart muscle that's not working normally.
- Magnetic resonance imaging (MRI). A cardiac MRI can provide still or moving pictures of how the blood is flowing through the heart and detect irregularities.
- Computerized tomography (CT). CT scans combine several X-ray images to provide a more detailed cross-sectional view of the heart.
- Coronary angiogram. To study the flow of blood through your heart and blood vessels, your doctor may use a coronary angiogram to reveal potential blockages or abnormalities. It uses a dye and special X-rays to show the inside of your coronary arteries.
- Chest X-ray. This test is used to take still pictures of your heart and lungs and can detect if your heart is enlarged.
Your doctor may recommend a stress test to see how your heart functions while it is working hard during exercise or when medication is given to make it beat fast.
In an exercise stress test, electrodes are placed on your chest to monitor heart function while you exercise, usually by walking on a treadmill. Other heart tests may also be performed in conjunction with a stress test.
Tilt table test
This test is sometimes used to help your doctor better understand how your tachycardia contributes to fainting spells. Under careful monitoring, you'll receive a medication that causes a tachycardia episode.
You lie flat on a special table, and then the table is tilted as if you were standing up. Your doctor observes how your heart and nervous system respond to these changes in position.
Your doctor may order additional tests as needed to diagnose an underlying condition that is contributing to tachycardia and judge the condition of your heart.
Treatments for tachycardia are designed to address the cause of the condition as well as slow a fast heart rate when it occurs, prevent future episodes and minimize complications.
Stopping a fast heart rate
A fast heartbeat may correct itself, and you may be able to slow your heart rate using simple physical movements. However, you may need medication or other medical treatment to slow down your heartbeat.
Ways to slow your heartbeat include:
Vagal maneuvers. Your doctor may ask you to perform an action, called a vagal maneuver, during an episode of a fast heartbeat.
Vagal maneuvers affect the vagus nerve, which helps regulate your heartbeat. The maneuvers include coughing, bearing down as if you're having a bowel movement and putting an ice pack on your face.
Medications. If vagal maneuvers don't stop the fast heartbeat, you may need an injection of an anti-arrhythmic medication to restore a normal heart rate. An injection of this drug is administered at a hospital.
Your doctor also may prescribe a pill version of an anti-arrhythmic drug to take if you have an episode of a fast heartbeat that doesn't respond to vagal maneuvers.
- Cardioversion. In this procedure, a shock is delivered to your heart through paddles, an automated external defibrillator (AED) or patches on your chest. The current affects the electrical impulses in your heart and restores a normal rhythm. It's generally used when emergency care is needed or when maneuvers and medications aren't effective.
Preventing episodes of a fast heart rate
With the following treatments, it may be possible to prevent or manage episodes of tachycardia.
Catheter ablation. This procedure is often used when an extra electrical pathway is responsible for an increased heart rate.
In this procedure, a doctor inserts catheters into your groin, arm or neck and guides them through the blood vessels to your heart. Electrodes at the catheter tips can use extreme cold or radiofrequency energy to damage (ablate) the extra electrical pathway and prevent it from sending electrical signals.
Catheter ablation does not require surgery to access the heart, but it may also be performed in conjunction with other heart valve or artery repair surgeries.
Medications. Pill versions of anti-arrhythmic medications may prevent a fast heart rate when taken regularly.
Other types of drugs, such as calcium channel blockers and beta blockers, may be prescribed either as an alternative to or in combination with anti-arrhythmic medications.
- Pacemaker. Some types of tachycardias may be treated with a pacemaker. A pacemaker is a small device that's surgically implanted under your skin. When the device senses an abnormal heartbeat, it emits an electrical pulse that helps the heart resume a normal beat.
Implantable cardioverter. If you're at risk of having a life-threatening tachycardia episode, your doctor may recommend an implantable cardioverter-defibrillator (ICD).
The pager-sized device is surgically implanted in your chest. The ICD continuously monitors your heartbeat, detects an increase in heart rate and delivers precisely calibrated electrical shocks, if needed, to restore a normal heart rhythm.
Surgery. Open-heart surgery may be needed in some cases to destroy an extra electrical pathway causing tachycardia.
In another type of surgery, called the maze procedure, a surgeon makes small incisions in heart tissue to create a pattern or maze of scar tissue. Because scar tissue doesn't conduct electricity, it interferes with stray electrical impulses that cause some types of tachycardia.
Surgery is usually used only when other treatment options don't work or when surgery is needed to treat another heart disorder.
Preventing blood clots
Some people with tachycardia have an increased risk of developing a blood clot that could cause a stroke or heart attack. Your doctor may prescribe a blood-thinning medication to help lower your risk.
Treating an underlying disease
If another medical condition is contributing to tachycardia, such as some form of heart disease or hyperthyroidism, treating the underlying problem may prevent or minimize tachycardia episodes.
Exercise and weight loss can help limit some of the health risks associated with tachycardia by reducing the negative effects of high blood pressure and sleep apnea.
If you have a plan in place to deal with an episode of a fast heartbeat, you may feel calmer and more in control when one occurs. Talk to your doctor about:
- How to take your pulse and what a normal pulse rate is for you
- When and how to use vagal maneuvers if they are appropriate for you
- When to call your doctor
- When to seek emergency care
Seeking support from family and friends also can help you reduce stress and better manage your tachycardia.
Whether you first see your family doctor or get emergency care, you'll likely be referred to a doctor trained in heart conditions (cardiologist) for one or more appointments for a complete evaluation.
If possible, bring along a family member or friend who can give some moral support and help you keep track of new information. Because there may be a lot to discuss, it will be helpful to prepare as much as possible.
What you can do
Make a list ahead of time that you can share with your doctor. Your list should include:
- Symptoms you've experienced, including any that may seem unrelated to your heart
- Key personal information, including any major stresses or recent life changes
- Medications, including vitamins or supplements
- Questions to ask your doctor
List your questions from most important to least important in case time runs out. Basic questions to ask your doctor include:
- What is likely causing my fast heart rate?
- What kinds of tests do I need?
- What's the most appropriate treatment?
- What kind of risks does my heart condition create?
- How will we monitor my heart?
- How often will I need follow-up appointments?
- How will other conditions I have or medications I take affect my heart problem?
- Do I need to restrict my activities?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask additional questions.
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:
- When did you first begin experiencing symptoms?
- How often have you had episodes of a fast heartbeat?
- How long have the episodes lasted?
- Does anything, such as exercise, stress or caffeine, seem to trigger or worsen episodes?
- Does anyone in your family have heart disease or a history of arrhythmias?
- Has anyone in your family experienced cardiac arrest or died suddenly?
- Do you smoke?
- How much alcohol or caffeine do you use?
- Do you use recreational drugs?
- Are you being treated for high blood pressure, high cholesterol or other conditions that may affect your circulatory system?
- What medications do you take for these conditions, and do you take them as prescribed?