Under conditions of stress, including viral infection, cytotoxic agents, and oxidative stress, activation of NRG-1/ErbB signaling can protect myocardial cells against apoptosis.[27] In contrast to embryonic and neonatal cardiomyocytes, adult myocardial cells are terminally differentiated and have lost the ability to proliferate. Therefore, growth of adult cardiac cells is commonly characterized by hypertrophy and an increased content of contractile proteins.[30] However, studies have shown NRG-1 promotes myocardial regeneration through hyperplasia, and prevents hypertrophy surrounding infarcted areas.[31]

Reference
Wiki: Cardiomyocyte apoptosis