I Have Been Fit, Ate Carefully, And Exercised All My

I have been fit, ate carefully, and exercised all my life. My weight now is less than it was when I was 18. but for a few months I had atrial fibrillation. a cardioversion to address this problem failed but I was put on medication which controlled the a-fib. about a month later, I had an ablation, which was successful but apparently my heart stopped, resulting in the need for CPR. consequently, I underwent an electrophysiological study during which the specialist performed another successful ablation but recommended a pacemaker, which was placed in my chest about two weeks ago. now I have had a few instances of sudden sharp pain in the right side of my chest. what is causing this and will it go away?