Suggest Treatment For Supra Ventricular Tachycardia

I have been diagnosed with supra ventricular tachycardia. I have been also having PVC s. I have continued with regular exercise and my pulse have been varying a lot. This evening while doing nothing but relaxing it was 118. I take Benadryl for allergies in the evening. My cardiologist has told me they are all benign and not dangerous. Shouldn t resting pulse be much lower after 4 weeks of cardio exercise. Some time it is in the 60 one minute and then back in the 80 to 100 range 5 minutes later?