Different areas of the brain are responsible for different functions. The symptoms of stroke depend on the area affected. Symptoms can be changes in sensation, movement, sight, speech, balance, and coordination.
A sudden cardiac arrest is the result of defective electrical activity of the heart. Patients may have little or no warning, and the disorder usually causes instantaneous death. A heart attack -- myocardial infarction -- typically is caused by clogged coronary arteries that reduce blood flow to the heart muscle.