What Increases Your Risk?

Supraventricular tachycardia (SVT) can happen to anyone. If you have an episode of SVT, the problem with your heart's electrical system can be temporary and triggered by several factors. Examples include:

• Drinking too much caffeine or alcohol (energy drinks with high caffeine levels are a common cause)
• Smoking
• Untreated thyroid disorders
• Going through psychological and physical stress
• Using illegal drugs
• Having family members who have a history of rapid heart rate (tachycardia)

In addition, certain conditions can increase your risk of developing SVT:

• Congenital heart defect or prior heart surgery
• Anemia
• Chronic respiratory illness
• Abnormally high thyroid function (hyperactive thyroid)
• Coronary heart disease
• Certain cardiac medications

Some other medications, such as digoxin or antihistamines, can increase risks of developing SVT, too.

When to Call a Doctor

Generally, SVT is not life-threatening. Sometimes, SVT does not cause any symptoms, and you may not need any treatment. However, you should talk to your health care professional or go to the emergency room if you have any concerning symptoms. Those include:

• Dizziness
• Lightheadedness
• Fainting (syncope) or near fainting
• Chest pain

Techniques called "vagal maneuvers" can help slow down or stop an episode of SVT. Some examples of these maneuvers:

• Exhaling strongly through a small tube or closed airway
• Coughing or gagging
• Putting your face into ice-cold water
• Holding your breath and bearing down (Valsalva maneuver)

If these steps fail to end or slow down your rapid heart rate, you should talk to your health care professional or go to an emergency department.