Good day dr!, I am ena san diego, 31 years old female, I have a resting heart rate of 105 rpm, it gets to 120-140 with a little physical activity. I tested negative for hyperthyroidism and pheochromocytoma. I also undergone stress test and 2D-echo, my cardiologist told me that I have normal heart with a fast heart rate. He prescribed ivabradine 7.5 but didn’t give any diagnosis. Is this Inapropriate Sinus Tacychardia? Aside from a fast heart beat, I also feel tired most of the time, I am hypertensive, I have GERD, constipation, heat and cold intolerance. All of these symptoms came 3 years ago, and I have been to different doctors and no one can diagnose what I have, most of them will say everything is normal. How come it will be normal when I feel all these symtoms, help me doctor, thank you