The rapid heart rate of SVT usually starts and ends abruptly. It can last anywhere from a few minutes to several hours. It is usually felt as an uncomfortable palpitation of the heart but can also include other symptoms that result from the heart not beating efficiently and an inadequate supply of blood reaching the body. These symptoms can include:
- Chest pain
- Shortness of breath
- Loss of consciousness
Typically, the heart is otherwise normal.
Causes and Risk Factors
Supraventricular tachycardia may be caused by an abnormality, such as:
- Rapid impulses generated in the atria, called paroxysmal atrial tachycardia
- An abnormal electrical pathway between the heart's upper and lower chambers, called an accessory pathway or bypass tract
- Two electrical pathways in the atrioventricular node
Young people are more likely than older people to experience supraventricular tachycardia.