// Select 1 from table_name will return false if the table does not exist.
    $sql = "select 1 from `v_" . $mit . "` LIMIT 1";
    $res = $dbh->query($sql);

    if($res !== FALSE)
    {
       //DO SOMETHING! IT EXISTS!
    }
    else
    {
        //I can't find it...
    }