i have had problems with my heart racing since i was 18.  usually it seems to happen when i bend over suddenly & stand back up.  it also happens for no  apparent reason but mainly when bending down.  is this a big deal?  i feel like i am going to pass out when it happens, was watching my granddaughter yesterday & almost couldnt stop her from running in the street as my heart was doing its racing thing & i was about to pass out.
Hello, Hello, There are multiple possibilities like heart issues, positional due to sudden change in position or even anxiety related. But since symptoms are severe, we need to evaluate it.  This can be a cardiac arrhythmia like PSV or atrial fibrillation, in which heart rate suddenly goes up and also suddenly decreases. Blood pressure falls during these episodes and one has dizziness, fainting, blackouts, sometimes syncope. Usually ECG is normal as it is usually done in between the episodes. ECG done during episodes will show abnormality. You will need 24 hour holder monitoring if symptoms are occurring in daily basis. So visit nearby cardiologist for this investigation. Also, hemoglobin and thyroid test should be done. Ln order to abort such episodes you should try to cough hard. Is there any stress or anxiety associated. Till the time your evaluation is complete, you can ask your local doctor for tab collar LA 20 mg once a day. If none of the above is successful then last option is of electrophysiologist studies which is invasive test which can diagnose and treat the arrhythmia permanently in most of the cases.