What is svt in medical terms

Supraventricular tachycardia is an abnormally fast heartbeat. It occurs when faulty electrical connections in the heart set off a series of early beats in the upper chambers of the heart atria. SVT starts above the heart's ventricles supraventricular in the two upper chambers or a cluster of cells called the atrioventricular AV node. To understand how this occurs, it can be helpful to understand how the heart beats.

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 the sinus node in the right upper chamber atrium.

The sinus node sends out electrical signals that normally start each heartbeat. These electrical signals move across the atria, causing the heart muscles to squeeze and pump blood into the ventricles.

Next, the signals arrive at the AV node. The AV node slows down the electrical signals. This slight delay allows the lower heart chambers to fill with blood. When the electrical signals finally get to the muscles of the ventricles, the lower heart chambers squeeze contract , which pumps blood to the lungs or to the rest of the body.

In a healthy heart, this heart signaling process usually goes smoothly, resulting in a normal resting heart rate of 60 to beats a minute. SVT occurs when faulty electrical connections in the heart set off a series of early beats in the atria. When this happens, the heart rate becomes so fast so quickly, the heart doesn't have enough time to fill with blood before the chambers contract.

As a result, you may feel light-headed or dizzy because your brain isn't getting enough blood and oxygen. Supraventricular tachycardia is the most common type of arrhythmia in infants and children. It also tends to occur more often in women, particularly pregnant women, though it may occur in anyone. Over time, untreated and frequent episodes of supraventricular tachycardia may weaken the heart and lead to heart failure, particularly if there are other coexisting medical conditions. In extreme cases, an episode of supraventricular tachycardia may cause unconsciousness or cardiac arrest.

To prevent an episode of supraventricular tachycardia, it's important to know what triggers the episodes to occur and try to avoid them. Healthy lifestyle changes can help protect your heart. You might want to try:. For most people with supraventricular tachycardia, moderate amounts of caffeine do not trigger an episode of SVT.

Due to an increased risk of sudden cardiac death, people with Wolfe-Parkinson White syndrome are advised to have curative catheter ablation. Wolff-Parkinson-White syndrome is congenital , developing in utero. Although present from birth, the tachycardias rapid heartbeats that result from the abnormal electrical connection often take years or decades before they become a problem.

Atrial tachycardia is responsible for about 5 percent of PSVTs. It occurs when an electrical impulse fires rapidly from a site outside the sinus node and circles the atria, often due to a short circuit.

Palpitations a feeling of fluttering in the chest. Fainting syncope. To "catch" an episode, your doctor may give you an ECG monitor to wear at home that will record your heart rhythm over time. These include:. Holter monitor : a portable ECG you wear continuously for one to seven days to record your heart rhythms over time.

Event monitor : a portable ECG you wear for one or two months, which records only when triggered by an abnormal heart rhythm or when you manually activate it. A normal resting heart rate is 60 to beats per minute bpm. But with SVT your heart rate suddenly goes above bpm.

This can happen when you're resting or doing exercise. It's important to get it checked out. You might need a test, such as an electrocardiogram ECG , to find out what's going on. Conditions that affect the lungs, such as chronic obstructive pulmonary disease COPD , pneumonia, heart failure, and pulmonary embolism, can raise your risk for multifocal atrial tachycardia MAT , a type of supraventricular tachycardia. Many experts believe that Wolff-Parkinson-White syndrome may in some cases be inherited.

If you have a first-degree relative, which is a parent, brother, or sister, with this disorder and he or she has symptoms, talk with your doctor about your risk for this abnormal heart rhythm. Call or seek emergency services immediately if you have a fast heart rate and you:. Call your doctor if you are having fluttering in your chest palpitations that persists and does not go away quickly or if you have frequent palpitations.

Call your doctor right away if you have symptoms that could mean your device is not working properly, such as:. Most people who have supraventricular tachycardia need to see a cardiologist or electrophysiologist for follow-up care. An exact diagnosis is important because the treatment you receive depends on the type of tachycardia you have.

Supraventricular tachycardia can sometimes be diagnosed simply on the basis of a medical history and physical exam and a few simple tests.

Tests that may be done to monitor your heart and diagnose the type of fast heart rate that you have include:. After finding tachycardia, your doctor may need to search for its cause. The specific tests needed depend on the particular tachycardia. These tests may include:. Your treatment for supraventricular tachycardia SVT depends on a few things.

They include what type of SVT, how often you have episodes, and how severe your symptoms are. The goals of treatment are to prevent episodes, relieve symptoms, and prevent problems.

When episodes of supraventricular tachycardia SVT start suddenly and cause symptoms, you can try vagal maneuvers. Your doctor will teach you how to do vagal maneuvers safely. These are things such as bearing down or putting an ice-cold, wet towel on your face. Your doctor may also prescribe a short-acting medicine that you can take by mouth if vagal maneuvers don't work.

This allows some people to manage their SVT without having to visit the emergency room repeatedly. If your heart rate cannot be slowed using vagal maneuvers, you may have to go to your doctor's office or the emergency room, where a fast-acting medicine can be given to slow your heart rate. If the arrhythmia does not stop and symptoms are severe, electrical cardioversion , which uses an electrical current to reset the heart rhythm, may be needed.

If you have recurring episodes of supraventricular tachycardia, you may need to take medicines, either on an as-needed basis or daily. Medicine treatment may include beta-blockers , calcium channel blockers, or other antiarrhythmic medicines. In people who have frequent episodes, treatment with medicines can decrease recurrences. But these medicines may have side effects.

Many people with supraventricular tachycardia have a procedure called catheter ablation. This procedure can stop the rhythm problem in most people. Ablation is considered safe, but it has some rare, serious risks.

If supraventricular tachycardia occurs in someone who has significant coronary artery disease , the heart may not receive enough blood to keep up with the demands of the increased heart rate. If this occurs, the heart may not get enough oxygen, potentially causing angina symptoms such as chest pain or pressure or a heart attack.

Mild supraventricular tachycardia, with short episodes that don't happen often, doesn't typically weaken the heart or lead to heart failure. But some people have a higher risk of getting heart failure, such as those who have a heart valve disease. If tachycardia is left untreated, repeated and long episodes of tachycardia can lead to heart failure known as a tachycardia-mediated cardiomyopathy.

But this heart failure might be stopped, or reversed, if the supraventricular tachycardia is stopped with treatment. You can reduce your risk of having episodes of supraventricular tachycardia by avoiding certain stimulants or stressors, such as nicotine, some medicines for example, decongestants , illegal drugs stimulants, like methamphetamines and cocaine , and excess alcohol. If fast heart rates continue, long-term medicines may be used to help prevent a recurrence of the fast heart rate.

Home care includes monitoring your supraventricular tachycardia SVT and trying to slow your heart when a fast heart rate occurs. To monitor your condition, you may find it helpful to keep a diary of your heart rate and your symptoms. Your doctor may suggest that you try vagal maneuvers —such as holding your breath and bearing down or putting an ice-cold, wet towel on your face—to slow your heart rate.

Your doctor will help you learn these procedures so you can try them at home when your fast heart rate occurs. Check your pulse when you have symptoms, and record the information in your diary. Be aware that if your heart is beating rapidly, it may be hard to feel your pulse and get an accurate count of your actual heart rate.

By keeping a diary of your heart rate and symptoms, you may be able to identify stressors—such as drinking alcohol or smoking—that trigger episodes. Also, it's usually important to avoid overuse of nicotine or alcohol and the use of illegal drugs, such as stimulants like cocaine, ecstasy, or methamphetamine. Doctors also warn against using diet pills or "pep" pills, ephedrine, ephedra, the herb ma huang, or other stimulants.

So most people do not have to avoid chocolate, caffeinated coffee, tea, or soft drinks. For severe symptoms, such as chest pain, shortness of breath, or feeling faint, you may be given fast-acting antiarrhythmic medicines by health professionals in the hospital emergency department, where your heart can be monitored.

Fast-acting antiarrhythmic medicines commonly used to slow the heart rate during an episode include:. Long-term use of an antiarrhythmic medicine may also be needed to reduce the chance of having more episodes of supraventricular tachycardia or to reduce the heart rate during these episodes.