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 Humboldt penguin, Spheniscus humboldti, lives on the coasts of Peru and Chile and islands off western South America. Like most Spheniscus penguins, these birds grow to a height of around 2 feet and weigh 9 pounds. Humboldt penguins breed in climates ranging from arid to hot and humid.