The heart is a muscle about the size of your fist that pumps blood around the body. When the heart is functioning properly, it has a specific rhythm controlled by a mass of specialized heart tissue ...

Recent trials of intensive glycemic control suggest a possible link between hypoglycemia and excess cardiovascular mortality in patients with type 2 diabetes. Hypoglycemia might cause arrhythmias ...

Biologist Terrie Williams works with Puka, an Atlantic bottlenose dolphin, at Long Marine Laboratory, UC Santa Cruz. (Photo by David Williams) A Weddell seal peers up from a breathing hole in ...

A cardiac arrhythmia is any abnormal heart rate or rhythm. In normal adults, the heart beats regularly at a rate of 60 to 100 times per minute, and the pulse (felt at the wrist, neck or elsewhere) ...

Almost everyone occasionally experiences irregular heartbeats when their heart may feel as if it is racing or skipping a beat. That sensation, however, may point to a serious health issue when it ...

A new study of dolphins and seals shows that despite their remarkable adaptations to aquatic life, exercising while holding their breath remains a physiological challenge for marine mammals. The study ...