The blue whale (Balaenoptera musculus) has the largest heart of any living creature. It can weigh over 1,500 lb (680 kg) and be as large as a small automobile. The aorta is large enough for an adult to crawl through and it pumps approximately 15,000 pints of blood as compared to 8 pints in a human being.

The heart of the blue whale can beat just five or six times per minute when it surfaces and even slower when the animal dives. In comparison, a human heart usually beats seventy times per minute whle resting.