Hi Thanks for writing in. I am a qualified and certified cardiologist. I read your mail with diligence. Let me assure you that heart rate of 120 does not lead to cardiomyopathy or congestive heart failure. Yes when you write about heart rate of 200 it concerns me you had to be investigated for the following: 1. Inappropriate Sinus Tachycardia 2. Paroxysmal Supra ventricular Tachycardia 3. Intermittent Atrial Fibrillation With or without abnormal thyroid function. Best suggestion I can give you is to seek an appointment with a cardiologist who would thoroughly examine you and apart from ECG if needed would do the appropriate test. That would be reassuring to everyone that you do not have any illness. Let me remind you normally heart beats for about 100,000 times a day (72x60x24) and one percent of these beats could be out rhythm normally and most frequently some people who are more perceptive or sensitive can get disturbed by these normally abnormal beats . Good Luck Best Wishes Dr Anil Grover