I've never been entirely convinced "dying of a broken heart" is actually what's happening in that scene.
With these movies, it's always important to remember that Lucas is a visual storyteller first and foremost. His own assessment of his writing ability is mediocre to poor, so if you ever want to really understand his intent then you must forget the dialogue & the exposition and just watch what's actually happening. Look at the way the scenes are designed, framed and edited. That's his canvas.
So when I look at Padme's death I'm not seeing a random, poorly explained medical condition, I'm seeing the birth of something evil and unnatural and parasitic. What I see is her heartbeat syncing up his. With her last breath comes his first. I think what this means is the part of him that was so desperate to keep her became a twisted, hungry, grasping, clawing thing that literally (though certainly unconsciously) reaches out and drains the life out of her. On some deep level, he quite literally never let her go after he grabbed her in his fury.
This whole scene is so steeped in both the literal and the symbolic one doesn't have to dig too deep to get what's going on here.
Symbolically, Padme is dying because she represents the good in Anakin (in a sense, they're both dying.) Literally, Padme is dying because Vader is draining her life force to stay alive.
Symbolically, the twins and Vader are being born simultaneously because they represent the hope for his future and an indication that there is still a tiny piece of Anakin still alive in there. Literally: because Vader is killing Padme and her body is sacrificing what little it has left to save the twins.
So not so much a broken heart as a stolen life force.
I really like that interpretation, Rev. I just happened to stumble in here inadvertently, and It's funny because as I finished reading the first of these two posts and @Prax's just after, my IMMEDIATE thought before I even got to your follow-up was: "So what Palpatine told him was true...from a certain point of view"!If she were truly loosing the will to live, then her last words would not be a desperate plea to Obi-Wan that Anakin can still be redeemed. So like I said, that's not what's happening. Ignore the text; examine the subtext.
As for Palpatine's assertion: I've always wondered why he said that with such certainty. Did he know for a fact she was dead? Did he just say that to piss Vader off? If so then what if she happened to be still alive? Would he have had to have her hunted down and killed just to cover his arse? I think the most logical explanation is that he knew because Vader did drain the life from her and Sidious stood by and watch the whole thing, sensing exactly what was going on.
So what he told him was true, from a certain point of view.![]()

Whatever the exact mechanism/dynamic at work, it's always been quite clear to me, thematically speaking, that by turning to the dark side in a desperate effort to "save" Padme from the fate he has foreseen for her, Anakin actually causes her death, bringing about by his own actions the very thing he was seeking to prevent in so acting. A self-fulfilling prophecy. The more one tightens one's grip, the more will slip through one's fingers...