What do they mean when they say "...he fluttered pulses?"

Richard Cory commands attention. He is regal and graced in
all his glory. When he simply speaks good morning, he flutters pulses. The people's
hearts flutter when he speaks something as simple as a good
morning:

And
he was always quietly arrayed, 
And he was always human when he
talked; 
But still he fluttered pulses when he said, 
"Good
Morning!" and he glittered when he
walked.

The people are in awe
of Richard Cory. They hold him in high esteem. They long to be just like him. They are
astonished and fascinated by his riches. They think he is everything a person could wish
to be:

...we
thought that he was everything 
To make us wish that we were in his
place.

Just seeing Richard
Cory causes the people to long to breathe in his graces. That is why their pulses
flutter. Richard Cory makes such an impression on the people until they are enraptured
by his presence. He is schooled in grace and charm. He causes the people's hearts to
beat a little faster. That is what is meant by his ability to flutter
pulses.