Re: Heartrate Threshold

[Tivers <Tivers@aol.com>]

In a message dated 98-05-17 14:24:20 EDT, suendavid@worldnet.att.net writes:

<< I don't know whether this would apply to horses but there are other
 species that have MUCH higher heart rates---rodents get up around 600
 bpm all the time, and although obviously much smaller, the physics of
 pressure and ventricular filling are the same.  I think I read somewhere
 that hummingbirds have a normal HR of around 2400 bpms, although their
 heart is a little different.  So I'm not so sure a horse's heart
 wouldn't be capable of re-filling and pumping out a fresh load of blood
 at 240 bpms---after all, it has been documented on more than one
 occasion.
 
 Susan >>

My information comes from Dr. Fred Fregin and others who specialize in equine
cardiovascular systems. 

ti