For millennia the heart was thought to be the seat of emotions — the source of love, of course, but also kindness and courage. To lose heart is to lose the fight, and perhaps even one's life.
In a literal sense, a weak heart means death. Unfortunately, sudden cardiac arrest is the leading natural cause of death in the United States.
If you reach a certain age without developing cancer or Alzheimer's disease, chances are you'll never get them. At that point, barring an accident, you're more likely to die from simple cardiac arrest, probably in your sleep. A painless death, but one that can be postponed with proper diet and exercise.
