How true is this?

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.