Side effect of blood pressure medication?

[alanp46]

I have been engaging in a fitness routine at my local gym for over 5 years. My routine starts with 30 minutes of cardio on an elliptical or treadmill, followed by another 10-15 minutes on a stationary bike. I then follow with 30-45 minutes of weight training. A few months ago I was diagnosed with high blood pressure (142/90) and prescribed Accuretic 10-12.5. At that dosage, I didn't really notice any effect of the medication on my workout routine. However, recently my doctor increased the Accuretic to 20-12.5 and I have noticed that I am unable to sustain the same intensity level in my cardio routine. Where my heart rate would previously climb to around 138-142bpm while on the elliptical, I now find that my heart rate climbs 145-150bpm (or higher) during the same period. At one point last week I felt very energetic and was pushing myself a little harder than usual and started to feel palpitations. I immediately slowed down and took my pulse and my heart rate was 163. I now keep better tabs on my heart rate and slow my pace when it starts going higher than 142. Could the increased dosage of Accuretic make my heart rate increase like this?

[alanp46]

Addendum to this question post. I am a 56 yr old male, non-smoker.