Hello, The most common cause of syncope is heart issues such as heart arrhythmia. Another common cause is vaso-vagal syncope a very common syncope due to overactivity of the parasympathetic nervous system often triggered by pain or intense emotions. Other possible causes would include metabolic alterations which you seem to have been checked about. In many cases when it is a matter of an isolated episode no cause is identified. If this remains a single episode I don t think you should continue with any more tests, your doctors seem to have done all the necessary. Only if repeated episodes would go with more investigations such as prolonged heart rhythm monitoring. As for cholesterol-lowering Mediterranean diet and physical activity are the best means, if not enough medication with statins may be added. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Olsi Taka, Neurologist