A heart attack is known as the silent killer. 

Here is a remedy I found while researching.

You have to have made a tincture of African Bird Peppers. (350,000 hu) heat units. Take a handful, blend them in a blender using wood alcohol, aka 80 proof vodka as your liquid. Blend together for one minute.

Put in a mason jar, cover and leave for 14 days. Then it's ready.

If you have an attack, place a dropper full under your tongue. (oh it burns) but it will stop the heart attack.

Keep a small bottle with an eye dropper in it so someone else can administer it if you are passed out and carry one in your glove compartment.