Your heart has its own pacemaker—a system of electrical impulses that helps control the rhythm and the number of times your heart beats per minute. As it beats, the heart muscle squeezes oxygen-rich blood out to the body and then relaxes to fill with blood again. Usually, this happens 60 to 80 times per minute. But if you have supraventricular tachycardia, or SVT, it means your heart beats faster than normal—usually more than 100 beats per minute.
Many people feel their heart race from time to time, for example when they exercise or are under extreme stress. However, SVT is due to a problem with your heart’s electrical system. SVT begins in the upper two chambers called the atria. With SVT, your heart is pumping so fast that it does not relax enough to be able to completely fill with blood. This reduces the amount of blood supplied to the brain and body. As a result, you may feel chest tightness, short of breath or dizzy, although some people have no symptoms at all.
In most cases, SVT is not cause for alarm. But if you notice your heart racing or fluttering, you should call your doctor or seek immediate medical care. Learn all you can to stay in tune with your heart’s rhythm. Use this condition center to learn more about living with supraventricular tachycardia. You can also read about the latest research, create a list of questions to ask your doctor and much more.
Overview
Supraventricular tachycardia, also known as SVT, is a common abnormal heart rhythm that can affect all ages. When you have SVT, the electrical system in your heart isn’t working right. You might experience a sudden rapid heartbeat, which can lead to shortness of breath, chest pain and, in rare cases, loss of consciousness.
SVT often ends suddenly. It stops either on its own or when you take an action to slow your heart rate. These are called vagal maneuvers and include gagging or coughing. In some cases, you might need medication injected into a vein by emergency medical services or when you are in the ER.
While there are some known triggers for SVT, such as caffeine, stress and exercise, often an episode has no clear triggers. For example, SVT could occur while you are relaxed watching TV or it could wake you up from sleep.
After the first episode of SVT, sometimes no treatment is needed. The next attack could occur several years down the road and might not justify taking medication every day. When patients experience more than one episode, medicines could help reduce the number of times they occur. The most commonly used medications are beta-blockers and calcium channel blockers. Other medications such as anti-arrhythmic drugs also could be used. But sometimes medications are not that effective, and you could still experience SVT.
Another treatment option for SVT is to have an ablation. Ablation is a procedure that is usually done while you are sedated but still conscious. The goal is to find the tissue causing the rapid heartbeat and destroy it (burn). This procedure doesn’t require a long stay in the hospital, has a high success rate, and a low complication rate. It can be considered as first-line therapy for SVT because it can cure SVT and remove the need for medical therapy. Talk with your health care professional about the treatment options, risks and benefits to decide what is right for you.