to get an ECG which is one of several strategies they could use. (e.g. lately I've been interested in Heart Rate Variability which has gotten me looking at reading heart rate with cameras, radars, pressure gauges, ultrasound, etc.)
"Analysis of the data suggests that a blue whale’s heart is already working at its limit, which may explain why blue whales have never evolved to be bigger."
Incredible to think of the volume of all the blood it's pumping around.
I don't understand how that would limit evolution. Bigger bodies can evolve together with bigger hearts, as already witnessed with the very whales being researched.
I watched the whole video and there is no heartbeat sound, which is what I was expecting as well. I think that they recorded the signal, not the sound that the heart makes when pumping blood.
> Looking at the big picture, the researchers think the whale’s heart is performing near its limits. This may help explain why no animal has ever been larger than a blue whale – because the energy needs of a larger body would outpace what the heart can sustain.
"The Etruscan shrew has a very fast heart beating rate, up to 1511 beats/min (25 beats/s) and a relatively large heart muscle mass, 1.2% of body weight."
(to illustrate - machine guns typically do 600-900 rounds/min)
I wonder whose muscle fiber is stronger per unit mass - the whale's or the shrew's...
Note they put a Holter monitor on it
https://www.pnas.org/doi/10.1073/pnas.1914273116
to get an ECG which is one of several strategies they could use. (e.g. lately I've been interested in Heart Rate Variability which has gotten me looking at reading heart rate with cameras, radars, pressure gauges, ultrasound, etc.)
30 BPM at the surface, 4 bpm while diving.
"Analysis of the data suggests that a blue whale’s heart is already working at its limit, which may explain why blue whales have never evolved to be bigger."
Incredible to think of the volume of all the blood it's pumping around.
I don't understand how that would limit evolution. Bigger bodies can evolve together with bigger hearts, as already witnessed with the very whales being researched.
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At the risk of being annoying, I'm pretty sure they have evolved to be bigger quite a lot, until they reached their maximum viable size.
These are peak free diver goals. Though I'm sure I'd be guaranteed to black out at 4bpm, haha. Incredible.
Anyone got a direct link to or time index of the recording? I skipped around the video on the linked page but it was all music.
I watched the whole video and there is no heartbeat sound, which is what I was expecting as well. I think that they recorded the signal, not the sound that the heart makes when pumping blood.
> Looking at the big picture, the researchers think the whale’s heart is performing near its limits. This may help explain why no animal has ever been larger than a blue whale – because the energy needs of a larger body would outpace what the heart can sustain.
Fascinating to learn such details!
Could an animal have several hearts?
yes. I know octopuses and squids have three hearts. Just looked it up and it seems no mammal has more than one heart.
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It’s interesting Genesis talks of whales before many other things.
A Whale's tachycardia is my bradycardia. Huh.
There are documented cases of perfectly healthy humans with resting heart rates under 30bpm.
https://www.guinnessworldrecords.com/world-records/lowest-he...
and the highest heart rate belongs to the smallest mammal
https://en.wikipedia.org/wiki/Etruscan_shrew
"The Etruscan shrew has a very fast heart beating rate, up to 1511 beats/min (25 beats/s) and a relatively large heart muscle mass, 1.2% of body weight."
(to illustrate - machine guns typically do 600-900 rounds/min)
I wonder whose muscle fiber is stronger per unit mass - the whale's or the shrew's...