What Causes a Blue Whale's Heart to Beat So Slowly?

💡 The Answer

• A blue whale's resting heart rate can be as low as 2 beats per minute.
• This slow pace results from massive body size and a large stroke volume per beat.
• The heart weighs about 400 pounds and pumps blood through arteries as wide as a person's torso.
• When surfacing to breathe, the heart rate speeds up rapidly to supply oxygen to tissues.