I was recently diagnosed with PSVT (specifically AVNRT based on the ECG) and I am considering radiofrequency ablation since I can't take the medication that can help as I already have a lower resting heart rate. (but ironically borderline high blood pressure.) My question is, I was found to have transient first degree heart block at various times, as well as 3.5 second pauses during sleep while on monitor. Is it any more likely that ablation of the slow pathway for AVNRT would increase the chance that I could develop higher degree heart block and need a pacemaker at some point after the surgery? I have read that heart block sometimes develops after ablation and can go away...since I already have first degree heart block I wonder if the procedure is more risky? (Btw, the heart block was detected on monitor after taking a calcium channel blocker for my bp...it seemed to go away when I quit the meds but the EP says the med didn't cause it...likely it was already there and just brought it out). Not sure if this helps but when I have a normal ECG sometimes I tend to have a slightly longer QRS complex (I think that's what its called). Mine registers on ECG at 202...so barely longer than normal. My EP seems to think that if this happens after ablation for AVNRT then I probably already needed a pacemaker then or would have eventually, but I am pretty young and so if avoiding the ablation longer could prolong needing one, so be it. (I should note that he is not referring to me needing a pacer because of over-ablation of my AV node...I know that is a very small risk of surgery. I am referring to any risk of progressive heart block due to my existing condition) Thanks!