Thanks for writing in HCM.
Whenever you feel this problem count your pulse manually. If Your pulse is in between 60-100 per minute, then nothing to worry about. Heart problems have symptoms like Chest pain, palpitations, shortness of breath
associated with exertion , radiating pain
in arms or jaws. There are some risk factors for heart disease
like High Cholesterol
level, Hypertension, Diabetes Mellitus
, Family History, Smoking, Increasing age , Obesity and Stress. Most probably your problems are due to anxiety. You have to avoid stress. You can take anxiolytic medicine under the supervision of a doctor, if problem is severe. You can do holter test for missing beats precautionary. You should consult a doctor to clarify all the doubts.
Wishing you a good health.