During an episode of SVT , your heart beats about to times per minute, but it can occasionally beat faster or slower. Most people with supraventricular tachycardia live healthy lives without restrictions or treatment.
For others, lifestyle changes, medication and heart procedures may be needed to control or eliminate the rapid heartbeats and related symptoms. The main symptom of supraventricular tachycardia SVT is a very fast heartbeat beats a minute or more that may last for a few minutes to a few days. The fast heartbeat may come and go suddenly, with stretches of normal heart rates in between.
Some people with SVT have no signs or symptoms at all. In infants and very young children, signs and symptoms may be difficult to identify. They include sweating, poor feeding, pale skin and a rapid pulse.
If your infant or young child has any of these symptoms, ask your child's doctor about SVT screening. Supraventricular tachycardia is generally not life-threatening unless you have heart damage or other heart problems. However, in extreme cases, an episode of SVT may cause unconsciousness or cardiac arrest.
Call your doctor if you have an episode of a very fast heartbeat for the first time, and if the abnormal heartbeat lasts longer than a few seconds. Some signs and symptoms may be related to a serious health condition.
Call or your local emergency number if you have an episode of SVT that lasts for more than a few minutes, or if you have an episode with any of the following symptoms:. SVT occurs when the electrical signals that coordinate your heartbeats don't work properly. For some people, a supraventricular tachycardia episode is related to an obvious trigger, such as exercise, stress or lack of sleep. Some people may not have a noticeable trigger.
In a typical heart rhythm, a tiny cluster of cells at the sinus node sends out an electrical signal. The signal then travels through the atria to the atrioventricular AV node and into the ventricles, causing them to contract and pump blood. 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.
You may have to temporarily wear a portable EKG to pick up events as they occur. Another maneuver can be described as blowing into your fist as if it is a trumpet mouthpiece. If you cannot resolve the SVT on your own, you may need to see your doctor or go to the ER for a fast-acting medication or even electrical cardioversion, a procedure that uses an electric current to reset the heart's rhythm.
However, for more stubborn cases, there is a procedure called catheter ablation , which destroys the part of the heart that causes the problem. This procedure is the gold standard and has a 99 percent success rate. We do this procedure more than any other ablation. There are ways to prevent SVT at home by avoiding certain triggers. Common triggers include alcohol, caffeine, smoking, some over-the-counter decongestants, diet pills, and drugs such as cocaine and methamphetamine.
For most people who have SVT, the heart still works normally to pump blood through the body. During an episode of SVT, the heart's electrical system doesn't work right, causing the heart to beat very fast. The heart beats at least beats a minute and may reach beats a minute. After treatment or on its own, the heart usually returns to a normal rate of 60 to beats a minute.
SVT may start and end quickly, and you may not have symptoms. SVT becomes a problem when it happens often, lasts a long time, or causes symptoms. Most episodes of SVT are caused by faulty electrical connections in the heart. SVT also can be caused by certain medicines.
Examples include very high levels of the heart medicine digoxin or the lung medicine theophylline. Other types of SVT may be caused by certain health problems, medicines, or surgery.
Other symptoms include near-fainting or fainting syncope , shortness of breath, chest pain, throat tightness, and sweating.
Your doctor will diagnose SVT by asking you questions about your health and symptoms, doing a physical exam, and perhaps giving you tests. Your doctor:. If you do not have an episode of SVT while you're at the doctor's office, your doctor probably will ask you to wear a portable electrocardiogram EKG , also called an ambulatory electrocardiogram.
When you have an episode, the device will record it. Your doctor also may do tests to find the cause of the SVT. These may include blood tests, a chest X-ray , and an echocardiogram , which shows the heart in motion. Some SVTs don't cause symptoms, and you may not need treatment. If you do have symptoms, your doctor probably will recommend treatment.
If these treatments don't work, you may have to go to your doctor's office or the emergency room. You may get a fast-acting medicine to slow your heart rate. If the SVT is serious, you may have electrical cardioversion , which uses an electrical current to reset the heart rhythm.
The goals of treatment are to prevent episodes, relieve symptoms, and prevent future problems. You and your doctor can decide what type of treatment is right for you. Your options may include:. You can try some things at home to help prevent SVT by avoiding the things that trigger it. Examples of things you can try:. To find your triggers, keep a diary of your heart rate and your symptoms.
You might find, for example, that smoking or alcohol causes your SVT episodes. For most people, moderate amounts of caffeine do not trigger SVT. So most people do not have to avoid chocolate or caffeinated coffee, tea, or soft drinks. Two common types of supraventricular tachycardia—atrioventricular reciprocating tachycardia AVRT and atrioventricular nodal reentrant tachycardia AVNRT —are caused by an abnormal electrical pathway in the heart and often occur in people who do not have any other type of heart disease.
What causes this abnormal pathway might not be clear. Some lifestyle factors can raise your risk of having an episode of supraventricular tachycardia SVT , such as overuse of nicotine or alcohol, or use of illegal drugs, such as stimulants like cocaine or methamphetamine. Decongestants that contain stimulants should also be avoided, including oxymetazoline such as Afrin and other brands and pseudoephedrine such as Sudafed and other brands.
Doctors also warn against using nonprescription diet pills or "pep" pills, because many contain ephedra, ephedrine, the herb ma huang, or other stimulants. Congenital heart defects can raise the risk of having supraventricular tachycardia. 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.
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