How Real is the Death note?
Heart attack poison Video
Heart Attack Gun Websites
http://historybuff.com/cia-has-heart-attack-gun-because-course-they-do-3n49DyBBqQM1
http://www.military.com/video/guns/pistols/cias-secret-heart-attack-gun/2555371072001
https://www.longroom.com/discussion/389992/the-cia-s-heart-attack-gun
Just a lot of Heart attack websites you can find just by googling Heart Attack gun.. here is just a few i found
The Lrad
https://www.lradx.com/