There is much that occurred in those few hours...much sadness...столько боли...
It would take much time to explain, for you all to understand.
*Slowly makes his way out of the room, and steps outside to recollect his thoughts*
(Oh, GOSH is this a hard question. This is one of the MOST dramatic events to occur in the Russian Revolution in my opinion; when the Romanov family was massacred on July 17th, 1918. What's even more chilling, is that the 95th anniversary was just yesterday....I didn't realize that until now. O__O"
I don't know if Ivan actually committed the murders or not, but in my mind, I'm pretty sure they gave the task to him. As a sort of 'rebirth', if you will, and as a sign of him wholly committing himself to the new Soviet government, by snuffing out any chance of the Tsars ever returning to claim the throne. It's a cruel thing to do to one's own country, but...in a way, I believe Ivan would have preferred to do this event himself anyways.
It's not because he loathes or hates the Romanov's themselves, but simply because he is aware of the tortures this family could go through, if he does not complete this task himself. If Ivan wouldn't do it, then someone else would. And would most likely make it more painful for them.
So in the end, Ivan knew this event had to be done, and did so with a cold outlook, to hide the torture he was going through inside. Like he states above, it's a family he helped to raise, and a way of life he nurtured for over 700 hundred years. Being the executioner of something you've held dear for such a long time....such a loss can effect you in drastic ways, I would think.
I wouldn't be surprised if Ivan suffered from heart pains and migraines for days after this event; the Tsar and his family, the center of the monarchy which had run the country for such centuries, had died. And was replaced with a completely new regime of order. It takes time to adjust to such drastic changes.
I may or may not be thinking too hard about this question...but I like giving legitimate answers. Please excuse my rambling~ I personally consider this a very serious topic. v__v)
Translation : "Я сожалею ..." = "I am sorry..."