What is the relationship between heart rate and animal life span?

What is the relationship between heart rate and animal life span? What three phases in the work of the heart are characteristic for one heartbeat in mammals?

The more often the heart beats, the shorter the life span of the animal and, in most cases, the smaller its size. One of the slowest heartbeats in a blue whale.

By the way, a child’s heart beats more often than an adult’s.

Phases in the work of the mammalian heart: atrial contraction, ventricular contraction, rest.

The contraction of the atria and ventricles is called systole, it lasts 0.4 seconds (3: 1, respectively);

the rest period – diastole, also lasts 0.4 seconds.