Is a sinus tachycardia same thing as supraventricular tachycardia?

No: Sinus tachycardia is the normal fast heart rate that results from a stressful situation, physically or emotionally (running, being upset, having fever, etc...). Svt is an arrhythmia that usually requires abnormalities of the electrical conduction system of the heart, and if frequent and troubling needs directed treatment. Sinus tachycardia does not require treatment of its own usually.

Not completely: "supra-ventricular" means 'above the ventricle' and the sinus node is indeed above the ventricle, so st is one type of svt. Atrial fibrillation, flutter, ectopic atrial tachycardia all fit this description. Usually when talking about svt (or psvt), we refer to a rhythm coming from another specific source, such as a re-entry loop.

No: Sinus tachycardia i a normal physiological increase in heart rate and can happen with exercise , fever etc. Supra ventricular tachycardia is an abnormal rhythm usually caused by short circuits or re- entry.

Depends: Depends on how fast or how slow, the cause for the abnormal rate and whether or not it is causing any symptoms. Both abnormally slow and fast heart beats can cause congestive heart failure and syncope (fainting). Persistent fast heart beats can cause weakness of heart muscle referred to as tachycardia induced cardiomyopathy.