Narrator: This is Science Today. There's a saying in cardiac care that ‘time is muscle' - meaning, the sooner one gets help after a heart attack, the better the odds the heart muscle will not be damaged after an attack. Dr. Harold Bernstein is a pediatric cardiologist at the University of California, San Francisco.
Bernstein: When cardiac muscle is damaged, there really is no inherent repair process that can replace the damaged muscle. And so the heart is left with whatever living tissue has not been damaged. In some cases, if that damage has been very small, the heart does a good job of compensating. But in many cases where the damage is severe, the heart can't compensate and as a result it puts stress on the rest of the heart to work in a way it's not meant to and over time, that results in heart failure.Narrator: Bernstein's lab is currently exploring the potential of human embryonic stem cells to model the development of heart muscle and to explore these cells as a potential therapy for damaged cardiac muscle. For Science Today, I'm Larissa Branin.