I had a rapid heart rate that went from 76beats to 132 beat in forty minutes then started to come down but it took two hours to return to 84 beats per minute this happened about six months ago als then it went to 160 beats at rest what could be causing this Iam a 53 year  women
Hello, 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. ECG should be done but 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. So visit nearby cardiologist for this investigation.LN order to abort such episodes you should try to cough hard. Also, hemoglobin and thyroid test should be done. 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.