>heart attack guns exist
True.
Electrolasers:
https://en.wikipedia.org/wiki/Electrolaser
https://www.army.mil/article/82262/
They are used to trigger cardiac arrest (heart failure) and kill the target, those targets often being holistic doctors:
https://everydayconcerned.net/2015/08/13/holistic-doctors-sudden-cardiac-arrest-targeted-individuals-remote-radiation-heart-attack-weaponry-how-to-protect-yourself/
source:http://2012portal.blogspot.com/2018/02/directed-energy-weapons.html (site comp'd sometime after 2018)