Quick question: If I attack with say Hydrogedden and my opponent has a Wildheart and he activates Rush Reclessly, can I take back my attack or not?

In order to "take back" an attack, a replay is required.

A replay can only happen if the # of monsters on the defending side has changed, or if the initial monster who was being attacked was removed from the field.

Since none of these requirements are being met, a replay will not occur.

You can not "take back" your attack in this scenario.

That's why cards like Rush Recklessly are so brutal.

Oh... I see. Thats what I thought, thanks.