What is supraventricular tachycardia?
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.
Types of SVT include:
- Atrioventricular nodal reentrant tachycardia (AVNRT).
- Atrioventricular reciprocating tachycardia (AVRT), including Wolff-Parkinson-White syndrome.
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 300 beats a minute. After treatment or on its own, the heart usually returns to a normal rate of 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.
SVT also is called paroxysmal supraventricular tachycardia (PSVT) or paroxysmal atrial tachycardia (PAT).
What causes SVT?
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.
Some types of SVT may run in families, such as Wolff-Parkinson-White syndrome. Other types of SVT may be caused by certain health problems, medicines, or surgery.
What are the symptoms?
Some people with SVT have no symptoms. Others may have:
- Palpitations, a feeling that the heart is racing or pounding.
- A pounding pulse.
- A dizzy feeling or may feel lightheaded.
Other symptoms include near-fainting or fainting (syncope), shortness of breath, chest pain, throat tightness, and sweating.