Slow resting heart rate & elevated blood pressure

Hi,

I'm a 65 yo male and for the past 35+ years I've done yoga/meditation and swum at least 3/4 mile every day.  My resting heart rate, as might be expected, is fairly low--somewhere between 53 & 63. In the past few years, though, my blood pressure has steadily risen, and when it went over 145 at my annual exam about a year ago, my primary physician placed me on Lisinopril - 10mg.  My pressure immediately dropped into the 110-120/70-80 range, but I got dizzy when I bent over and felt like I had no energy for exercising.  I tried lowering the dose to 5 mg, but still had similar symptoms.  My doc told me to stop taking the Lisinopril, as I seemed to be someone who didn't do well with "low" blood pressure.  BTW, my cardiogram came back fine, and I have no causal factors such as stress, smoking, overweight, etc.

As I was concerned about carrying around high blood pressure, I tried 2.5 mg of Lisinopril, and that seemed to yield a happy medium where my pressure was typically in the 130-140/80-90 range and I still felt ok.  I hadn't taken my pressure for a few months, though, and about a month ago I found I was in the 150-160/100-110 range, so I'm now varying the Lisinopril dose.  In taking my pressure since then, I'm finding an almost one-to-one correlation between lowest resting heart rate and highest blood pressure readings.  When I record a 155+ reading my heart rate is in the low 50s and when my pressure's less than 125 (which still does not feel very good/ energetic) it's up around 70-72.  

I know there's a formula that indicates that heart rate X pressure is a constant, so if I want to maintain my low resting heart rate (which is good I think) am I fated to have high blood pressure (which is bad I think)?  Any comments would be most welcome. Thanks!