PVC’s (premature ventricular contractions or extra heart beats) and Rapamycin?

New to rapamycin 1mg weekly. I have a history of frequent PVC’s (premature ventricular contractions or extra heart beats). They were measured as about 1000 per hour with two 24-hr Holter monitor sessions and responded very well to Flecainide (antiarrhythmic). Normally if I miss a dose and PVCs start so I never miss a dose. Started having bouts of tri- and quadrigeminy on the third day. Only last an hr or so. Wondering if anyone else has experienced this? Otherwise, sleeping like a baby, still doing my 9000 stair steps per day on the backside of our local dam daily. No change in exercise tolerance.