SVT is a regular rhythm disturbance that originates either from the upper chambers of the heart (the atria) or the electrical connections between the top and bottom chambers.
It is most frequently caused by an extra electrical connection that can form a short circuit. This circuit runs faster than the normal pacemaker of the heart and produces the sensation of palpitations. Usually with SVT, the palpitations start abruptly and stop just as quickly as they started. Episodes can be as frequent as daily attacks or infrequent as once a year. They can be treated with tablets and most are curable by modifying the abnormal circuit using ablation treatment.