Tachycardia

Tachycardia (tak-ih-KAHR-dee-uh) is the medical term for a heart rate over 100 beats a minute. Many types of irregular heart rhythms (arrhythmias) can cause tachycardia.

A fast heart rate isn't always a concern. For instance, the heart rate typically rises during exercise or as a response to stress.

Tachycardia may not cause any symptoms or complications. But if left untreated, some forms of tachycardia can lead to serious health problems, including heart failure, stroke or sudden cardiac death.

Treatment for tachycardia may include specific maneuvers, medication, cardioversion or surgery to control a rapid heartbeat.

Types

There are many different types of tachycardia. Sinus tachycardia refers to a typical increase in the heart rate often caused by exercise or stress.

Other types of tachycardia are grouped according to the part of the heart responsible for the fast heart rate and the cause. Common types of tachycardia caused by irregular heart rhythms (arrhythmias) include:

• Atrial fibrillation (A-fib). This is the most common type of tachycardia. Chaotic, irregular electrical signals in the upper chambers of the heart (atria) cause a fast heartbeat. A-fib may be temporary, but some episodes won't end unless treated.
• Atrial flutter. Atrial flutter is similar to A-fib, but heartbeats are more organized. Episodes of atrial flutter may go away themselves or may require treatment. People who have atrial flutter also often have atrial fibrillation at other times.
• Ventricular tachycardia. This type of arrhythmia starts in the lower heart chambers (ventricles). The rapid heart rate doesn't allow the ventricles to fill and squeeze (contract) 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 be life-threatening.
• Supraventricular tachycardia (SVT). Supraventricular tachycardia is a broad term that includes arrhythmias that start above the ventricles. Supraventricular tachycardia causes episodes of a pounding heartbeat (palpitations) that begin and end abruptly.
• Ventricular fibrillation. Rapid, chaotic electrical signals cause the ventricles to quiver instead of contracting in a coordinated way. This serious problem can lead to death if the heart rhythm isn't restored within minutes. Most people who have ventricular fibrillation have an underlying heart disease or have experienced serious trauma, such as being struck by lightning.

Symptoms

When the heart beats too fast, it may not pump enough blood to the rest of the body. As a result, the organs and tissues may not get enough oxygen.

In general, tachycardia may lead to the following signs and symptoms:

• Sensation of a racing, pounding heartbeat or flopping in the chest (palpitations)
• Chest pain
• Fainting (syncope)
• Lightheadedness
• Rapid pulse rate
• Shortness of breath

Some people with tachycardia have no symptoms. The condition may be discovered when a physical exam or heart tests are done for another reason.

When to see a doctor

A number of things can cause a rapid heart rate (tachycardia). If you feel like your heart is beating too fast, make an appointment to see a health care provider.

Seek immediate medical help if you have shortness of breath, weakness, dizziness, lightheadedness, fainting or near fainting, and chest pain or discomfort.

A type of tachycardia called ventricular fibrillation can cause blood pressure to drop dramatically. Collapse can occur within seconds. Soon the affected person's breathing and pulse will stop. If this occurs, do the following:

• Call 911 or the emergency number in your area.
• If you or someone nearby is well trained in CPR, start CPR. CPR can help maintain blood flow to the organs until an electrical shock (defibrillation) can be given.
• If you're not trained in CPR or worried about giving rescue breaths, then provide hands-only CPR. Push hard and fast on the center of the chest at a rate of 100 to 120 compressions a minute until paramedics arrive. You don't need to do rescue breathing.
• If an automated external defibrillator (AED) is available nearby, have someone get the device for you, and then follow the instructions. An AED is a portable defibrillation device that can deliver a shock to reset the heart rhythm. No training is required to use the device. The AED will tell you what to do. It's programmed to give a shock only when appropriate.

Causes

Tachycardia is an increased heart rate for any reason. It can be a usual rise in heart rate caused by exercise or a stress response (sinus tachycardia). Sinus tachycardia is considered a symptom, not a disease.

Tachycardia can also be caused by an irregular heart rhythm (arrhythmia).

Things that may lead to tachycardia include:

• Fever
• Heavy alcohol use or alcohol withdrawal
• High levels of caffeine
• High or low blood pressure
• Imbalance of substances in the blood called electrolytes — such as potassium, sodium, calcium and magnesium
• Medication side effects
• Overactive thyroid (hyperthyroidism)
• Reduced volume of red blood cells (anemia), often caused by bleeding
• Smoking
• Use of illegal drugs, including stimulants such as cocaine or methamphetamine

Sometimes the exact cause of tachycardia can't be determined.

How does the heart beat?

To understand the cause of tachycardia, it may be helpful to know how the heart typically works.

The heart is made of four chambers — two upper chambers (atria) and two lower chambers (ventricles).

The heart's rhythm is controlled by a natural pacemaker (the sinus node) in the right upper chamber (atrium). The sinus node sends electrical signals that normally start each heartbeat. These electrical signals move across the atria, causing the heart muscles to squeeze (contract) and pump blood into the ventricles.

Next, the signals arrive at a cluster of cells called the AV node, where they slow down. This slight delay allows the ventricles to fill with blood. When the electrical signals reach the ventricles, the chambers contract and pump blood to the lungs or to the rest of the body.

In a typical heart, this heart signaling process usually goes smoothly, resulting in a resting heart rate of 60 to 100 beats a minute.

Risk factors

In general, growing older or having a family history of certain heart rhythm problems (arrhythmias) may increase the risk of arrhythmias that commonly cause tachycardia.

Lifestyle changes or medical treatment for related heart or other health conditions may decrease the risk of tachycardia.

Complications

Complications of tachycardia depend on:

• The type of tachycardia
• How fast the heart is beating
• How long the rapid heart rate lasts
• If there are other heart conditions

Some people with tachycardia have an increased risk of developing a blood clot that could cause a stroke (risk is highest with atrial fibrillation) or heart attack. Your health care provider may prescribe a blood-thinning medication to help lower your risk.

Other potential complications of tachycardia include:

• Frequent fainting or unconsciousness
• Inability of the heart to pump enough blood (heart failure)
• Sudden death, usually only associated with ventricular tachycardia or ventricular fibrillation

Prevention

The best ways to prevent tachycardia are to maintain a healthy heart and prevent heart disease. If you already have heart disease, monitor it and follow your treatment plan. Be sure you understand your treatment plan, and take all medications as prescribed.

Lifestyle changes to reduce the risk of heart disease may help prevent heart arrhythmias that can cause tachycardia. Take the following steps:

• Eat a healthy diet. Choose a diet rich in whole grains, lean meat, low-fat dairy, and fruits and vegetables. Limit salt, sugar, alcohol, and saturated fat and trans fats.
• Exercise regularly. Try to exercise for at least 30 minutes on most days.
• Maintain a healthy weight. Being overweight increases the risk of developing heart disease.
• Keep blood pressure and cholesterol levels under control. Make lifestyle changes and take medications as prescribed to control high blood pressure (hypertension) or high cholesterol.
• Stop smoking. If you smoke and can't quit on your own, talk to your health care provider about strategies or programs to help break the 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 and up to two drinks a day for men. For some health conditions, it's recommended that you completely avoid alcohol. Ask your health care provider for advice specific to your condition.
• Don't use illegal drugs or stimulants, such as cocaine. Talk to your health care provider about an appropriate program for you if you need help ending illegal drug use.
• Use medications with caution. Some cold and cough medications contain stimulants that may trigger a rapid heartbeat. Ask your health care provider 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).
• Manage stress. Find ways to help reduce emotional stress. Getting more exercise, practicing mindfulness and connecting with others in support groups are some ways to reduce stress.
• Go to scheduled checkups. Have regular physical exams and report any changes in your heartbeat to your health care provider. If your symptoms change or get worse or you develop new ones, tell your health care provider immediately.

Diagnosis

To diagnose tachycardia, a health care provider will usually do a physical exam and ask questions about your symptoms, health habits and medical history.

Tests

Tests, including cardiac imaging tests, may be done to confirm an unusually fast heartbeat and look for conditions that can cause an irregular heart rhythm (arrythmia). Tests to diagnose tachycardia may include:

• Electrocardiogram (ECG or EKG). This quick and painless test measures the electrical activity of the heart. During an ECG, sensors (electrodes) are attached to the chest and sometimes to the arms or legs. An ECG measures the timing and duration of each electrical phase in the heartbeat. Your health care provider can look for signal patterns to determine the type of tachycardia and how problems in the heart may be causing the fast heart rate.

  Some personal devices, such as smartwatches, offer electrocardiogram monitoring. Ask your health care provider if this is an option for you.

• Holter monitor. Your health care provider may recommend monitoring your heartbeat at home. This portable ECG device can be worn for a day or more to record the heart's activity during daily activities.
• Event monitor. This portable ECG device is intended to be worn for up to 30 days or until you have an arrhythmia or symptoms. You typically press a button when symptoms occur.
• Echocardiogram. An echocardiogram uses sound waves to create pictures of the heart in motion. It can identify problems with blood flow, the heart valves and the heart muscle.
• Chest X-ray. A chest X-ray can show the condition of the heart and lungs.
• Cardiac magnetic resonance imaging (MRI). A cardiac MRI can provide still or moving pictures of blood flow through the heart. This test is most often done to determine a cause of ventricular tachycardia or ventricular fibrillation.
• Computerized tomography (CT). CT scans combine several X-ray images to provide a more detailed cross-sectional view of the area being studied. A CT scan of the heart (cardiac CT) may be done if a health care provider is looking for a cause of ventricular tachycardia.
• Coronary angiogram. A coronary angiogram is done to check for blocked or narrowed blood vessels in the heart. It uses a dye and special X-rays to show the inside of the coronary arteries. A coronary angiogram may be done to look at the heart's blood supply in people who have ventricular tachycardia or ventricular fibrillation.

• Electrophysiological (EP) testing and mapping. This test, also called an EP study, may be done to confirm a diagnosis of tachycardia or to determine where in the heart the faulty signaling occurs. An EP study is mostly used to diagnose isolated arrythmias. Less commonly, it may be used to evaluate sinus tachycardia.

  In this test, a health care provider threads thin, flexible tubes (catheters) tipped with electrodes through the blood vessels to different areas within the heart. Once in place, the electrodes can map the spread of electrical signals through the heart.

• Stress test. Some types of tachycardia are triggered or worsened by exercise. During a stress test, the heart's activity is typically monitored while riding on a stationary bicycle or walking on a treadmill. Other heart tests may be done with a stress test. If you have difficulty exercising, a drug may be given to stimulate the heart in a way that's similar to exercise.
• Tilt table test. This test is sometimes used to help better understand how tachycardia contributes to fainting. Heart rate and blood pressure are monitored while lying flat on a table. Then, under careful supervision, the table is tilted to a position that mimics standing. The health care provider watches how the heart and the nervous system that controls it respond to the changes in position.

Treatment

The goals of tachycardia treatment are to slow a rapid heartbeat when it occurs and to prevent future episodes of a fast heart rate.

If another medical condition is causing tachycardia, treating the underlying problem may reduce or prevent episodes of a fast heartbeat.

Slowing a fast heart rate

A fast heart rate may correct itself. But sometimes medication or other medical treatments are needed to slow down the heartbeat.

Ways to slow a fast heart rate include:

• Vagal maneuvers. Vagal maneuvers include coughing, bearing down as if having a bowel movement and putting an ice pack on the face. Your health care provider may ask you to perform these specific actions during an episode of a fast heartbeat. These actions affect the vagus nerve, which helps control the heartbeat.
• Medications. If vagal maneuvers don't stop the fast heartbeat, medication may be needed to restore the heart rhythm.
• Cardioversion. This medical procedure is usually done by sending electric shocks to the heart through sensors (electrodes) placed on the chest. The shock affects the heart's electrical signals and restores a normal heartbeat. Cardioversion is generally used when emergency care is needed or when vagal maneuvers and medications don't work. It's also possible to do cardioversion with medications.

Preventing future episodes of a fast heart rate

The treatment of tachycardia involves taking steps to prevent the heart from beating too fast. This may involve medication, implanted devices, or other surgeries or procedures.

• Medications. Drugs to control the heart rate and restore a normal heart rhythm are typically prescribed for most people with tachycardia.

• Catheter ablation. In this procedure, a health care provider threads one or more thin, flexible tubes (catheters) through an artery, usually in the groin, and guides them to the heart. Sensors (electrodes) on the tip of the catheter use heat or cold energy to create tiny scars in the heart to block irregular electrical signals and restore the heart rhythm. It's often done when an extra signaling pathway is responsible for an increased heart rate.

  Catheter ablation doesn't require surgery to access the heart, but it may be done at the same time as other heart surgeries.

• Pacemaker. A pacemaker is a small device that's surgically implanted under the skin in the chest area. When the device senses an irregular heartbeat, it sends an electrical pulse that helps the heart resume the correct rhythm.

• Implantable cardioverter-defibrillator (ICD). Your health care provider may recommend this device if you're at high risk of developing ventricular tachycardia or ventricular fibrillation.

  An ICD is a battery-powered unit that's implanted under the skin near the collarbone — similar to a pacemaker. The ICD continuously monitors the heart rhythm. If the device detects an irregular heartbeat, it sends out low- or high-energy shocks to reset the heart's rhythm.

• Maze procedure. In this procedure, a surgeon makes tiny incisions in the upper half of the heart (atria) to create a pattern (or maze) of scar tissue. The heart's signals can't pass through scar tissue. So the maze can block stray electrical heart signals that cause some types of tachycardia.
• Surgery. Sometimes open-heart surgery may be needed to destroy an extra electrical pathway causing tachycardia. Surgery is usually done only when other treatment options don't work or when surgery is needed to treat another heart disorder.

Lifestyle and home remedies

If you have tachycardia or any type of heart disease, your health care provider will likely recommend following a heart-healthy lifestyle. Take these steps:

• Eat a healthy diet
• Don't smoke
• Get regular exercise
• Maintain a healthy weight
• Limit or avoid alcohol

Alternative medicine

Stress-relief techniques, such as meditation and yoga, might help slow the heartbeat and reduce tachycardia symptoms

Coping and support

If you have a plan in place to manage an episode of a fast heartbeat, you may feel calmer and more in control when one occurs. Ask your health care provider:

• How to take your pulse and what heart rate is best for you
• When and how to use vagal maneuvers, if appropriate
• When to call a health care provider
• When to seek emergency care

Seeking support from family and friends also may help reduce stress and better manage tachycardia.

Preparing for an appointment

If you have tachycardia, you'll likely be referred to a doctor trained in heart conditions (cardiologist).

Because there's often a lot to discuss, it's a good idea to be prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from the health care provider.

What you can do

Make a list ahead of time that you can share with your health care provider. Your list should include:

• Any symptoms, including those that may seem unrelated to your heart
• Key personal information, including any major stresses or recent life changes
• All medications you take and the dosages, including vitamins and supplements and drugs bought without a prescription
• Questions to ask your health care provider

Basic questions to ask your health care provider include:

• What is the likely cause of my fast heart rate?
• What kinds of tests are needed?
• 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?

In addition to the questions that you've prepared to ask your health care provider, don't hesitate to ask additional questions.

What to expect from your doctor

Your health care provider is likely to ask you a number of questions. Being ready to answer them may save time to go over any details you want to spend more time on. Your health care provider may ask:

• When did you first begin having 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 irregular heart rhythms (arrhythmias)?
• Has anyone in your family had cardiac arrest or died suddenly?
• Do you smoke?
• How much alcohol or caffeine do you use, if any?
• Do you use stimulant drugs?
• Are you being treated for high blood pressure, high cholesterol or other conditions that may affect your heart health?
• What medications do you take for these conditions, and do you take them as prescribed?

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