Ok so first thing first: what you SHOULD do when you think you have a cardiac event is call a fucking ambulance. That is absolutely the first step here. Get the professionals on the way so that you don’t fucking die. The most effective method to prevent dying from a heart attack (aside from regular checkup and being moderately active) is to learn to recognize what a heart attack presents like (the ‘classic’ presentation strikes true in less than fifty percent of the cases!) and be cautious.
Now what do the professional say about the cough thing? Well, the American Heart Association doesn’t endorse it as a standard practice, neither does its British pendant. And there’s a reason for that. Well, reasons. Number one is that it requires a conscious person. The next is that it actually takes a considerable bit of force to cough hard enough to pump blood into your brain, which is what the thing aims to do: put outside pressure onto your heart to keep your brain oxygenated during arrhythmia.
Now note how I explicitly said ‘arrhythmia’ up there. That’s because not every cardiac event, even if it causes lasting damage to the heart muscle, actually sends you into arrhythmia. If you ARE arrhythmic aka ‘your heart is no longer pumping anything at all’ then you are going to be unconscious very very quickly. Potentially a lot quicker than you can get start on the whole cough thing because panic brain is stupid brain.
if you’re still up and about then chances are, your heart is still beating and pumping, in which case the coughing won’t do shit anyways.
THEORETICALLY, if you manage to overcome panic brain and do the cough thing on yourself, while being arrhythmic, and you do it right (forceful and often enough to actually help. Please remember how fast CPR goes….) then it might help you stay conscious for a bit
BUT THEN YOU STILL NEED PROFESSIONAL HELP. Your heart doesn’t usually go arrhythmic for no reason. Something’s fucked. Something’s so fucked that one of the most vital organs in your body is clocking the fuck out on you. It can be an embolism in the chamber, or a clogged vein, or the nerves that make your heart go fucking up, but NONE of these things are actually fixed by coughing. The underlying source ALWAYS needs medical intervention. Some of these issues might resolve themselves if you’re lucky but banking on that would be foolish. Meaning that you would now, theoretically, have to call your ambulance, while coughing, and wait for said ambulance, also while coughing.
So really the first thing you should be doing IS ‘call an ambulance’
followed by ‘lay the fuck down so that your heart has less work to do’ and/or if possible ‘call neighbour/landlord/friend and have them sit by you’ because if you do pass the fuck out you’re going to need someone else to launch into the CPR like, on the spot.
The key to surviving cardiac arrest outside of a setting full of professionals is ‘someone is close by and does CPR until the professionals come’. You and your nearest and dearest being able to perform CPR, and perform good and correct CPR is going to be really, truly helpful and potentially live saving.
So like, hit up the reputable internet sources like the above linked two groups and check out what they got to say about the issue. I promise you they’re more informed than some fuck on the internet.