I am certain that you did not intend to send me into cardiac arrest. However, for the record, here in America it is never a good idea to sneak up on someone in a parking lot without a)giving them plenty of notice via some type of verbal initiation of conversation and b)without keeping enough space between you and the person you are approaching so that when they turn around they don't literally run into you.
I'm not quite sure about the crime rate in the Asian countries, but here in America crime is rampant...or so it seems....and quite a bit of it occurs in parking lots. People roam the streets with assault rifles and are not afraid to use them (unfortunately). Here in America when someone sneaks up on you in a parking lot, the first instinct is to protect your children, swing your purse, and start screaming for help. You are fortunate in that the response you got from me was a mere, "Good grief, don't ever sneak up that closely on someone in a parking lot ever again."
Seriously, you are lucky that I am one of the few who does not carry a gun, or a taser, or pepper spray (although I am now seriously considering options 2 and 3). Now, that my heart has resumed beating at its normal pace I hope you have learned your lesson. Welcome to America.