See below. Supraventricular tachycardia (svt) is an episodic fast heart rate that usually originates in the upper chambers of the heart. It usually starts all of a sudden and stops all of a sudden, usually is not life threatening by itself, and is mostly rather easily treatable with a cardiac procedure called ablation which is performed by an electrophysiologist.
Arrhythmia coming . From top chambers of the heart (atria)...Can be serious depending upon symptoms. See a cardiologist and get evaluated as many treatments are available.