Hello. Thank you for your question and welcome to HCM. I understand your concern. Most of the people sense the heart beat as normal and understand this and accept it as a normal, physiological phenomenon. Some people, like yourself, sense this as a pathological phenomenon. I understand that. Every minimal change in perceived physiological or normal functioning, is interpreted like pathological things. This is a cause for anxiety or fear (situational anxiety) in these people and may or may not be followed with a panic attack due to one questioning him/herself am I going to die? what is wrong with me? etc. Every time we assume a lying down position, our heart, that beats by vibrating our chest wall, comes closer to a certain area of the ribcage. If lying on the left side it is so close to the chest wall that can even vibrate the bed you are lying on. All the other symptoms you mentioned are triggered by the anxiety attack you have, because all types of anxieties have one thing in common: flush of adrenalin and noradrenalin in the system, which then produce the symptoms you perceive. Every thing you feel is real, but it is not pathological. Therefore, if the heart rate is regular, every symptom is attributed to the anxiety, which I depicted above. If this is the case, then there is nothing to worry about. But, if this phenomenon affects your quality of sleep, by reducing its hours, then I would recommend a consult with a psychiatrist about the possibility of being put on a trial with sedatives for one to two weeks. I hope I was helpful with my answer. Take care. Kind regards, Dr. Meriton