LONGECITY

We know how a "heart attack" --> Myocardial infarction happens, shouldnt it be possible to build a device which can scan for these signs and give a warning, so that the there would be a better chance for survival?

Heart diseases are the most likely diseases to kill people, shouldnt we do soemthing about that?

I believe a cardiogram does just that, but of course you're talking about a portable 'home device'. maybe there are such -? the best heart disease preventative, as far as I know, is good oral care and hygiene.

Indeed there are multiple such consumer devices, you can find some just by googling. It's not a bad idea - I've understood that often people are uncertain if they're experiencing heart-related symptoms, and sometimes dismiss the initial symptoms as something minor. A portable ECG device would be an easy fix for that. 

 

Best preventative would be exercise, I think

You are right, but sometimes even People who exercise can get Heart Problems.

I once saw an ECG device which was built in a Phone, it consisted of "pins" on the backside of the cell phone and those pins were placed on the chest so that an ECG could be taken.

I dont know if this thing was very accurat, and i havent seen it anywhere lately.