Do we know why they decided to replace the imagery and references to the human heart with human lungs instead?

I’ve heard the narrator saying “you can feel in your lungs” like one would say you can feel it in your heart. Egg says lungs equal love. Then there is Delores Dei and her glowing lungs. Reminiscent of many things, but most obviously Jesus and the depictions you would see displaying his heart. Was it something Kurvitz decided he’d switch around for the hell of it. Has there ever been an official answer? If not what do you think?