Rebuilding Broken Hearts; November 2004; Scientific American Magazine; by Smadar Cohen and Jonathan Leor; 8 Page(s)

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.

Medical interventions are allowing more people to survive the crisis of a heart attack. But at least a third of these will experience the subsequent steady weakening of their injured hearts, termed heart failure, for which there is only one cure at present: transplantation--a complicated, expensive alternative limited by a severe shortage of donors. Last year in the U.S., for example, more than 550,000 new cases of heart failure were diagnosed, but only about 2,000 transplants were performed. For the remainder of patients, quality of life steadily erodes, and less than 40 percent will survive five years after the initial attack.