1 Let's say it's 7:25 pm and you're going home (alone of course) after an unusually hard day on the job.
2 You're really tired, upset and frustrated.
3 Suddenly you start experiencing severe pain in your chest that starts to drag out into your arm and up in to your jaw. You are only about five km from the hospital nearest your home.
4 Unfortunately you don't know if you'll be able to make it that far.
5 You have been trained in CPR, but the guy that taught the course did not tell you how to perform it on yourself.
6 HOW TO SURVIVE A HEART ATTACK WHEN ALONE? 
Since many people are alone when they suffer a heart attack without help, the person whose heart is beating improperly and who begins to feel faint, has only about 10 seconds
left before losing consciousness.
7 However, these victims can help themselves by coughing repeatedly and very vigorously. A deep breath should be taken before each cough, and the cough must be deep and
prolonged, as when producing sputum from deep inside the chest.
A breath and a cough must be repeated about every two seconds without let-up until help arrives, or until the heart is felt to be beating normally again.
8 Deep breaths get oxygen into the lungs and coughing movements squeeze the heart and keep the blood circulating. The squeezing pressure on the heart also helps it regain
normal rhythm. In this way, heart attack victims can get to a hospital.
9 Tell as many other people as possible about this. It could save their lives!

Disclaimer!   I am not a doctor.   a $500 emergency room visit is cheaper than a $5000 funeral.

...right....!  If you're having a heart attack, and actually figure out you're really having a heart attack, about the last thing you're going to want to do is start coughing.  Deep breaths, MEH, depending on where the most PAIN is, and how it is affecting you, about the only thing you can muster is trying to minimize the pain... which is unavoidable!

It could be:
intense heartburn, that no heartburn medicine helps;
intense body/chest heat (ice cold shower time).
pain in the arm (under/inside it, from elbow to shoulder, maybe up to the neck);
a feeling of chest compression, shortness of breath (like you can't take a deep breath);
turning whitesh/blue, cool clammy sweat & feeling so lightheaded no body position helps (curiously, walking did help);

In order, that's how it hit me.   4-way bypass and I'm doing fine.  I had 100%, 100%, 95%, 90% blockages, with new little veins growing...  no damage at all.   A real quirk - 92 cholesterol (that got a lot of visitors, and questions, "What the hell are you doing here!?")

If you think you're having a heart attack  relax and dial 911.  Better to find out it was Papa John's, than suffer permanent damage.   Some things are hereditary, and it doesn't matter how good of shape you're in.   Bypass is nothing to be afraid of, now days, it's so routine, surgeons-in-training do it.   Sure the recovery time is longer than a Stent, but the difference is 30 years vs 5-10 years.   It is simply amazing what can be done today!

My step-dad (who is a Doctor), gave me this advice:  LISTEN TO YOUR DOCTOR & DO WHAT HE SAYS!  My birth dad died of a heart attack, in his own bed, 5 years after his 3-way bypass.