Supraventricular tachycardia

Supraventricular tachycardia (SVT) is an abnormally fast heart rhythm caused from improper electrical activity in the upper part of the heart. 
There are four main types: atrial fibrillation, paroxysmal supraventricular tachycardia (PSVT), atrial flutter, and Wolff–Parkinson–White syndrome.
Symptoms may include palpitations, feeling faint, sweating, shortness of breath, or chest pain.