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.
The classic tuxedoed penguins are found in Antarctica, along with the largest, the Emperor penguins, while Jackass penguins flourish in Namibia and South Africa and Humboldts live on a desert landscape near the coasts of Peru and Chile.