A heart broken by love usually heals with time, but damage to cardiac muscle caused by a heart attack gets progressively worse. Unlike liver or skin, heart tissue cannot regenerate, so the scar left after a heart attack remains a noncontractile dead zone.
By hobbling the heart muscle's normal synchronous contractions, the scar, known as an infarct, also increases strain on the healthy parts of the muscle, leading to further cell death and deformation of the cardiac wall. This cycle of deterioration can cause an infarct to double in size within just months.
This article was originally published with the title Rebuilding Broken Hearts.