Exercised Induced Hypertension
You said you take Lisinopril 30mg. Did you know that if Lisinopril works too good it can cause a rapid loss of blood pressure. I am a nurse and I heard this from a doctor. Maybe your pacemaker is not the issue. Talk to your doctor about your Lisinopril and your symptoms.
I hope all works out for you. BTW, Happy Fathers Day!