Polite Dissent

Flash #219 “Truth or Dare, part 1”
Geoff Johns, writer
Justiniano, penciler

Ashley Zolomon is discussing the Turtle, a villain who has the power to “steal speed” from people and objects and slow things down:

He put three guards in a coma, caused another’s heart to burst when he slowed the blood flow down.

Could the Turtle cause a coma?
Sure. If he caused the blood entering a person’s brain to slow down enough, toxins would build up and not enough oxygen would be delivered to the tissue. The brain would starve and be poisoned by its own byproducts. This is enough to cause a coma.

Could he cause a heart to explode?
Maybe.

1. Slowing the blood down throughout the body would cause less oxygen to get to organs and tissues, and a corresponding increase in the toxins in these areas. It would definitely be dangerous, but it wouldn’t cause a bursting heart.
2. If the Turtle slowed down the heart itself, the blood pressure throughout the body would actually drop (this is one of the ways the drugs known as beta blockers work). If the pressure dropped too low or the blood was too slow, you’d end up with the same situation described above. Potentially lethal, but not explosive.
3. What if the Turtle slowed down the blood just as it was leaving the heart — basically setting up a roadblock in the aorta? In this situation, the amount of blood in the heart would start to build up as blood was returned to the heart from the body. Could enough blood build up to burst the heart like a balloon? It’s unlikely. With no blood leaving the heart, there would be a drop in the blood pressure throughout the body, and this includes the pressure that is needed to return blood to the heart. There is probably not enough pressure to fill the heart to bursting, particularly since it would take an increasing amount pressure to force more fluid into an already overloaded heart.

   Of course, this is assuming that the guard in question had a healthy heart. If he had a weak heart, particularly one with the heart walls weakened with scarring from an old heart attack, then all bets are off.