The thing is, the way that scene was shot, with Amy doing the compressions on something below the camera's field of vision, they could have just used a CPR dummy for the compressions and made it look authentic.You can't have the regulars going around seriously injuring each other for the sake of a scene.
Also, I wondered why the Doctor couldn't have rigged the sonic screwdriver to deliver a defibrulation jolt. Last week we saw him gunning down Silents with it, surely the sonic has a defib setting.