(SVT)
a fast heart beat stemming from an abnormal area in the atria of the heart. It is often benign and relatively easily treated. However, it may be so fast that it reduces the pumping efficiency of the heart, causing a fall in blood pressure or heart failure. See also arrhythmia.
* * *
(SVT) any regular tachycardia in which the point of stimulation is located above the bundle branches, either in the sinus node, atria, or atrioventricular junction; it may also include those arising from large reentrant circuits encompassing both atrial and ventricular sites.Medical dictionary. 2011.