Human hearts respond differently than mouse hearts to two cardiovascular drugs !

Mice are the most popular animal model in physiology, but the mouse is
not a very good model for cardiac physiology. "A mouse's heart beats
about 600 times per minute, so you can imagine it is a little
different from humans, whose hearts beat on average 72 times per
minute," Efimov says.

"You can mutate in mice the gene thought to cause heart failure in
humans and you don't get the same disease, because the mouse is so
different," Efimov says.

Graham

http://www.innovations-report.com/html/reports/medicine_health/study_calls_question_reliance_animal_models_179691.html