How our solar system was born. 9 May 2016. Discover how a giant interstellar cloud known as the solar nebula gave birth to our solar system and everything in it.
Most deaths due to cardiac arrest are in older adults, particularly those with coronary artery disease. Cardiac arrest is the leading cause of death in young athletes, but the incidence of it is unclear. Perhaps 1 in every 50,000 sudden cardiac deaths a year occurs in young athletes.
Ventricular fibrillation is the most common cause of cardiac arrest. Ventricular fibrillation occurs when the normal, regular, electrical activation of heart muscle contraction is replaced by chaotic electrical activity that causes the heart to stop beating and pumping blood to the brain and other parts of the body.