Cayenne pepper, known to everyone may be convenient to stop acute bleeding externally [and likely also internally, but avoid the last situation without medical training]
It may also be lifesaving during heart attacks by putting a tiny bit under the tongue, according to Ayurvedic medicine..
For people with a dominant Pitta constitution, it should be avoided for heart attacks.

Ayurveda reconizes 3 main Doshas[constitutions: Vata,Pitta and Kapha.
It may be good to try to find out on the Internet what your main Dosha is, that means to what constitution you belong [or better, what seems to be your primary [ or maybe mixed] constitution]

If you are very stong Pitta the avoid Cayenne pepper.