<s>[INST] hi i was with my mum the other day and she was totally fine and later that evening she had what was like a fit but without the shaking she was ok one minute and gone blue and had passed out the next and came round after about 2 minutes her heart rate was high when ambulance came what as caused this [/INST] Hello Thanks for posting here. Going by your description it looks like she has got arrhythmia. Arrhythmias are disturbances in the heart rhythm which can cause such symptoms. When heart beats become fast and irregular or there is a short pause between beats, the brain does not receive blood supply for that moment. That's why she gets the episodes like fainting or fit like episodes. The fast heart rate which she got later may be due to compensatory action of the heart after an arrhythmia event. She has to get an ECG done which may show an arrhythmia event. If not detected on ECG, then a 24 hour holder monitoring which records the ECG throughout for 24 hours when the patient is home should be done.Meanwhile, a 2 D echo should be done to see whether there is any new onset cardiac event which is responsible for the same. The above symptoms can also occur due to narrowing of the heart valves which can be demonstrated by 2 D echo. Wishing her good health. Regards. </s>