There are not a lot of "only"'s in life, and medicine is no different. But, one week or so would be within the general range of risk from cardiac rupture, a typically catastrophic and fatal event as one might assume. Usually, the risk depends on the extent and location of damage and a slew of other risk factors including blood pressure control, diabetes, steroid use, age, recent infection, etc. When the heart is damaged or partly "dies" as in an infarction that area is vulnerable to the high pressures generated within the heart. In most cases preceding rupture the territory of heart death is significant leading to a generally reduced heart function and far less pressure generated with in the heart (hence, why these folks tend to have very low blood pressure and require significant ICU_level support to survive). In the week or so following the even, the areas that were "Stunned" around the now dead zone of the heart start to recover. This leads to a partial improvement in the heart's ability to pump, which in turns increases the pressure within the heart. Unfortunately, this can literally blow out the dead area of the heart and lead to rapid death.