This power was used to telekinetically destroy the victim's organs. On Korriban, Darth Tyranus used Force kill on the black-market dealer Auben's heart, killing her instantly. Darth Bane also used Force kill on his father by envisioning a giant hand squeezing his father's heart resulting in a fatal heart attack.
Darth Vader knew how to use this power, and demonstrated the ability to stop a victim's heart or freeze his lungs with the Force.