Condition Basics
What is supraventricular tachycardia (SVT)?
Supraventricular tachycardia (SVT) means that from time to time your heart beats very fast for a reason other than exercise, high fever, or stress. 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 100 beats a minute and may reach 250 beats a minute or more. After treatment or on its own, the heart usually returns to a normal rate of about 60 to 100 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.
What causes it?
Most episodes of SVT are caused by faulty electrical connections in the heart. Some types of SVT may run in families, such as Wolff-Parkinson-White syndrome. SVT also can be caused by certain health problems, heart and lung medicines, or surgery.
What are the symptoms?
When your heart is beating fast from SVT, you may feel a fluttering in your chest (palpitations) and have a fast pulse. You may feel lightheaded, be short of breath, or feel discomfort in the chest. Some people with SVT have no symptoms.
How is it diagnosed?
Your doctor may diagnose SVT based on a physical exam, your symptoms and history, and a test called an electrocardiogram (EKG, ECG). You may need other tests such as an electrophysiology study, blood tests, chest X-rays, or an echocardiogram to identify what type of SVT you have or find the cause.
How is SVT treated?
SVT does not always need to be treated. If needed, treatment options include medicine, cardioversion, and a procedure called catheter ablation. Your doctor may also teach you how to slow your heart rate on your own with physical actions called vagal maneuvers. You and your doctor can decide what treatment is right for you.
