I am 64 yr old female, 116 lbs weight, have sinus tachycardia , heart rates range from 95 when reclined to 155 when standing. I also experience extreme shakiness, dizzines and faint. I was once told that I had a heart murmur. My doctor has run a number of tests recently and she cannot find the cause, my blood pressure is also elevated. Should I have a cardiologist evaluate?