If you write die of disease with a specific disease's name and the person's time of death, there must be a sufficient amount of time for the disease to progress. If the set time is too tight, the victim will die of a heart attack after 6 minutes and 40 seconds after completing the Death Note.
Let's say Y has a Death Note. He also has Shinigami Eyes, and because he's a genius he can read in Shinigami time. So he wants to kill Z.
Z, bradykardie, dies of bradykardie at 11:59 on this date: 25.07.2062. Till he dies, he will always do whatever the person he knows as A tells him to do.
(Yes, Z is destined to die at the mentioned date.)
(A won't die, since he already wrote his own name in his Death Note.)
Would this work?