HI Thank for asking to HCM Your query really appreciated, as long as heart disease are concern it is less likely in this age unless it is the congenital kind of disease and for that I would advise to get done the cardiac evaluation that includes EKG, ECHO and with that the doubt of irregular heart beat and others, in your case dizziness could be due to hypoglycemia, or anxiety, else it may not be due to any illness, if such symptoms of pass out goes on happening on and often then better to get done the CT of brain, hope this information helps.