Very interesting video about the CIA that includes a section that talks about a special gun that can induce a natural looking heart attack.

CIA’s Heart Attack Gun

Former CIA employee Mary Embree discusses the infamous heart attack gun. The weapon was first made public during the Church Committee hearings in 1975. Very lethal & untraceable, using this weapon a murder is made to look natural. No doubt the CIA has been using this weapon and has most likely improved upon it since the 70’s.

clip of the 1975 Church Committee at 4:57

4:10 is particularly interesting.

Source:  https://www.youtube.com/watch?v=Uwy56QTV4cs