Secretariat's heart was twice as big as a normal thoroughbred because he had functional hypercardia

Drask said in comment #2548553:

Secretariat's heart was twice as big as a normal thoroughbred because he had functional hypercardia

You mean tachycardia right?

Bostimite said in comment #2589756:

You mean tachycardia right?

tachycardia = heart beats faster than normal
hypercardia = heart bigger than normal

So no, Drask was correct. Secretariat was born normal but upon checking he had hypercardia because he was specifically bred for it.

Drask said in comment #2548553:

Secretariat's heart was twice as big as a normal thoroughbred because he had functional hypercardia

Worth noting the joke here isn't so much about his heart. It's that his chest was so fucking big that his girth had to be custom made.

Girth: The harness that fixes the saddle to the horse's back by strapping underneath the horse's chest, nearer the forelimbs.

Notere said in comment #2630480:

Worth noting the joke here isn't so much about his heart. It's that his chest was so fucking big that his girth had to be custom made.

Girth: The harness that fixes the saddle to the horse's back by strapping underneath the horse's chest, nearer the forelimbs.

So basically, she has to special-order her bras.