What Increases Your Risk?

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

• Drinking too much caffeine or alcohol (energy drinks with high caffeine levels are a common cause)
• Smoking
• Going through psychological and physical stress
• Using drugs that stimulate the heart such as amphetamines and/or cocaine
• Having family members who have a history of SVT

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 artery disease

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. Some people have minor symptoms while experiencing SVT. 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 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
• Forcefully coughing
• Putting your face into ice-cold water
• Holding your breath and bearing down (Valsalva maneuver) like women do during labor

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.