During a fatal heart attack, at least 1 billion heart cells are killed in the left ventricle, one of the heart’s two big lower pumping chambers that move blood into the body.
In less severe coronaries, dead cardiac cells are replaced by connective tissue cells that form scar tissue in the damaged heart. But the result is never very satisfactory. Scarred ventricular walls are thin, and don’t contract very well — a problem in a workhorse organ designed for sustained pumping.
Inadequate heart repair concerns British-trained developmental biologist Christine Mummery, who has made cardiac cells her specialty. She’s the Harvard Stem Cell Institute Radcliffe Fellow, and will be in residence at Harvard for a semester.