Code

document.onkeydown = function (e)
{
    var diagram = Diagram.find('diagram');

    //move left
    if (e.keyCode == 37 && e.ctrlKey)
    {
        if (diagram.getActiveItem())
        {
            var item = diagram.getActiveItem();
            if (item.setBounds)
            {
                var r = item.getBounds().clone();
                r.offset(-10, 0);
                item.setBounds(r, true);
            }
        }
    }
}