Do I need a cardiologist?

I am a 57 year old healthy female.  Other than gallbladder removal (4 years ago) and a broken foot last summer,
I have had no medical problems.  About a month ago I went to a church blood drive and was turned down as a donor
because of a high pulse rate (over 100). BP was fair, a little eleveated in the high 120s and low 130s over high 70s and low 80s. After monitoring bp and rate for 2 days at home I saw my internist.  He ordered blood tests, including thyroid function and magnesium and potassium levels.  I also wore a Holter for 24 hours.  All blood tests came back normal and the Holter showed an average heart rate of over 100.  My doctor prescribed 25 mg of Toprol xl one time a day.  I have monitored bp and rate several times daily, and bp is good (117/67, for example) but pulse rate is still in 90's or low 100's.  I called his office today and he increased the dose to 2 times a day.  What I need to know is whether or not this is something that takes a while for the meds to take hold of, or should I follow my instinct (this IS the only heart I have) and consult a cardiologist?
Thank you for any advice you can offer.

[RNRita]

Hi there.  Toprol and the rest of the beta blockers are generally prescribed for high blood pressure.  They also help a fast heart rate so many doctors do use them for that reason.  I take atenelol and have for 21 years.  I had a resting heart rate of 96 so I know how you feel.  The atenelol worked wonders for me.  The day I started it (it was a high dose) my heart rate went down to 47.  My hubby wanted to take me to the ER and I told him to just let me alone....it felt so darned good!  Eventually, my HR went to around 72 on 25 mg.  You just need to get your dose right or find the right beta blocker.  Some do not take the heart rate down in certain people!