In 1985, Rivers appeared on 'Good Morning America', where Joan Lunden asked about her heart arrhythmia, a condition in which the heart unexpectedly beats out of sync, reported People magazine.
"All of a sudden you'll be on stage and hear 'tha-thud! It scares the hell out of me," Rivers told Lunden in the video.
Rivers then explained that the condition poses a very specific concern.
"When you go under, say for plastic surgery or something like that, that's when your heart can go out of kilter. So I'm always very careful," she said.