A stroke occurs when the blood supply to part of the brain is suddenly interrupted or when a blood vessel in the brain bursts, spilling blood into the spaces surrounding brain cells. Brain cells die when they no longer receive oxygen and nutrients from the blood or there is sudden bleeding into or around the brain. The symptoms of a stroke include sudden numbness or weakness, especially on one side of the body; sudden confusion or trouble speaking or understanding speech; sudden trouble seeing in one or both eyes; sudden trouble with walking, dizziness, or loss of balance or coordination; or sudden severe headache with no known cause. There are two forms of stroke: ischemic - blockage of a blood vessel supplying the brain, and hemorrhagic - bleeding into or around the brain.
A possible heart condition is ventricular fibrulation (VF) is a very fast, irregular heart rhythm in the lower heart chambers (ventricles). During VF the heart quivers and pumps little or no blood to the body. Consciousness is lost in seconds. If not treated immediately, VF will cause sudden cardiac arrest. VF is responsible for 75% to 85% of sudden deaths in persons with heart problems. VF is the primary cause of sudden cardiac death (SCD).
Many people don't know they are at risk for this condition until it happens.
VF is usually caused by a reduced amount of oxygen reaching the heart (ischemia) but can also be caused by electrolyte imbalances, acid-base disturbances, toxic responses due to proarrhythmic drugs, hyperthermia/hypothermia, drowning or any other situation where oxygen is cut off. Untreated, VF causes loss of oxygen to vital organs, absence of a pulse, loss of consciousness and death. In the US: the incidence of arrhythmias is greater than 4,300,000 cases. VF has been described as the initial rhythm in almost 70% of out-of-hospital arrests.