Hello. I read your concerns. Thank you for your query. Now, I spotted two possible cause for these symptoms, from the brief information you provided. First, as it is know sometimes happening to patients suffering from diabetes, who are on glucose-lowering agents (glibenclamid, insulin), the sugar can be lowered below normal range and this is a response to low glucose levels provided to the brain. If this is the case, patient feels weak, is covered in sweat, feels a tremor on his knees. This situation can be overcome with eating a candybar or drinking a glass of juice. Second, it can happen by various pacemaker dysfunctions (end-of-life battery, lead dislodgement), i.e. every problem with the pacemaker, which makes it not work properly when needed. To investigate this, you should go to you doctor s office, and test the pacemaker to see if it is working properly. I hope I was helpful. Take care. Feel free to consult again. Good day.