Board Thread:Spoilers!/@comment-25361971-20150128004028/@comment-25733960-20150402195205

Rumple's body is 300 years old. While being the dark one, the curse preserved his body. While being in Storybrooke, time was frozen.

But after he was banished in 4x11, his body was under "normal" conditions for 6 weeks, for the first time since he became the dar one. I think his heart issues could be a consequence of being a 300 years old body. Humans are not supposed to live that long.