Tachycardia SVT and ablation

Hi i am 33 years old mail i was diagnosed whith Thachycardia SVT at age of 22,i lived whith that for some years nothing mayor happend only few times visiting ER whith Heart rate at 220-240 BPM ,as it was geting more frequent betwin the time my doc. desided to put me for ablation,in april 06 i had an ablation and havent had tachycardia until 3 months ago,but i noticed that my heart rate was only 140-160 i went to ER but they culd not find somthing wrong EKG,all that was ok.but now i am geting irregular heart beats like every day as i enter ER room heart rythem goes normal 90-100,i had holter heart monitor for a week nothing happend,the day i took it off had one of those tachycardias.My resting Heart rate in the morning is 75-85 as i get up it can goes to 120.I dont take no medicine, my BP was 140/100 but i lost some weight and changed my livestyle now is 125/84.
I wonder am i geting panic attacks or is something with the heart?