Hello. Thank you for your question and welcome to HCM. I understand your concern. All the symptoms, like tightness in your throat, thirst etc. are part of the anxiety you experienced from an episode that was new and worrying to you. This is a property of all types of anxieties. Therefore, I think you should fall back asleep with no worries, should this happen again. Because, during sleep happens a phase that is called rapid eye movement (REM) phase. To put it simple, this is the phase during which dreams occur and it is characterized by a flush of adrenalin and noradrenalin in the system, hence the high heart rate. Some colleagues like to call it the nightmare heart rate . My opinion is that there is nothing to worry about. I hope I was helpful. Best regards. Dr. Meriton