Add the following entries to your user key bindings.
{ "keys": "ctrl+alt+left"], "command": "move_to", "args": {"to": "bol", "extend": false} },
{ "keys": "ctrl+alt+right"], "command": "move_to", "args": {"to": "eol", "extend": false} }
For future reference, you can rebind any keys you want in a similar fashion. Simply look up the command in the key binding file. Alternatively, if you know of a key combination that executes the command you want, you may enter “sublime.log_commands(True)” in the console. Then press the appropriate key binding. This will print out the command being executed to the console and the associated arguments.