For me, I've found anxiety to be a result of the physical effect. I wrote about this in another thread.... I have a heart condition that causes compromised function and while I have not had a heart attack that I know of I've had some scary episodes related to a combination of low blood pressure...
I know this is an old thread but I felt I needed to to create an account to reply to this with my own experience.
I don't think that there is a cardiac link per se but I do think there is a correlation in that MJ acts as a vaso-dilator. I've read that this dilation is what causes the munchies...