m heart rate had go to very fast last night at 3.00 am about 120 to 130 per minutes, when i change position and go to outdoor slowly and return to bedroom, it become normal and I sleep again. Again when i weak up in morning, again heart rate is about 110 to 120. This type of happen three times in 5 months . I tested for ECG, EcoCG,EEG, Ions, CBC,BP and DC. all are normal. Also sometime when i am in standing or sitting, a sudden cardiac arrest type of event occur and I have faint, sweeting.