Definitions for "Supraventricular tachycardia"
An arrhythmia similar to A-Fib in which the heart beats fast (100 to 240 beats per minute). SVT usually begins and ends suddenly. SVT often begins in childhood or adolescence. It is commonly caused by a variation in the electrical system of the heart. It is usually not dangerous, but can cause a drop in blood pressure and lightheadedness.
supraventricular tachycardia: rapid heart rhythms that originate in the atria or upper chambers of the heart
The most common type of SVT is atrial fibrillation, an irregular and rapid heartbeat in the upper chambers of the heart (or atria).