He does that anyway

I remember an old man who used to live in our neighborhood. He went paddling for about an hour or so, and started feeling this minor pain in his arm (which one I don't remember). We was sent to hospital and later died after one day had passed.

Therefore, my question to you is: Are you old too, Andrespetmonkey? Are you???

It's nothing (like a slightly arrogant doctor would say). It's definitely not the heart and nothing you need to check up unless it occurs frequently again or unless the symptoms significantly change.

Routinely in the US, high school and college/uni students die by undiagnosed heart aliments.  Too often the signs of danger are ignored.

Activity is great, but long periods of inactivity is not.  As BurningHouse mentioned.  Repeated long periods of inactivity, especially if you have blood that abnormally clots (Systemic Lupus Erythematosus), and or are dehydrated can result in blood clots that accumulate in your legs (deep vein thrombosis).  The length of activity isn't important, the length of inactivity, namely sitting, that can be a problem.  Once those clots begin forming, they don't easily breakup.  They take time.  In the meantime, continued inactivity only adds to their size.

DVTs can cause strokes, heart attacks, or pulmonary embolisms.

Your age doesn't make a difference.  Anyone of any age can experience a DVT and do.

I would talk to a doctor, just he/she knows and can make a determination if you need a CT Scan of your heart.  A doctors visit would be 30 minutes, and a CT Scan about the same if he/she felt it was appropriate.  Ignoring something doesn't make it go away.  I ignored an initial PE, a week later I was in the hospital barely able to breathe.  An hour isn't a lot to ask if it's the difference between life or death.  And if it ends up being nothing, or something minor, then you know.

It's obvious you have no knowledge about the human body whatsoever because the symptons he described are 100% certainly related to the heart.

I get that all the time, man up and ignore it. It's just your bodies way of saying fuck you! that's it.

That's what all the "Men" say. Men can be so stupid, my Dad was like this for awhile and he ended up having something really, really wrong. (Not going to explain it.) So don't be a stupid "Man", please.

Reading the OP, I assume he died.

Why people make threads regarding serious health conditions instead of going to a doctor is beyond me.

No I can assure you they aren't. I am a doctor and I meet patients with breast aches several times a week. Andrespetmonkey does not have a problem with his heart.

First of all heart related pain is never sharp or only a second long. Heart pain is diffuse and widespread rather than localised (and often of relatively mild intensity. But it can be very intense too) and it's prolonged (at least we are talking minutes of duration).

The numbness in his arm could have been an alarming symtom and heart related if the rest of the symptoms made sense, but numbness in an arm is also very commonly a benign symptom.

He probably had a stroke.