I have had 3 occasions in my life in the past 12 years where i suddenly collapsed to the floor . Nobody could figure out what was wrong . NOW I have had occasions where I wander off to my left but now it's worse . I will be standing and suddenly it's as if my left leg goes into a deep hole . It starts like something has pushed the back of my knee area . We used to play like that in school , it was fun to see the person go limp ...it's not now . It also starts to come on me when walking ...rubbery like warns me and then ...kaboom,, .left leg goes out from under me . Doc has ordered a 2nd EKG because she saw something bad in the 1st and wants to verify it ...did not tell me what it is .