Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm characterized by rapid and irregular beating.
Emperor penguin - Aptenodytes forsteri. This is the largest species of penguins. Emperor penguins are only found on and around the Antarctic continent, on the thick pack ice and rarely on mainland. They have a pale yellow, open (breast and chin patch are one) patch on chin and breast. A long, thin and curved bill, typical for fish eaters. Very dark grey back and blue black head.
However, all known species of penguins live naturally in the southern hemisphere. Contrary to general belief, Penguins do not live only in icy conditions. Outside of Antarctica, Penguins usually inhabit desertic regions and rocky islands where there are not a large number of land predators, so their incapacity to fly is not an issue.