Ventricular fibrillation is one type of arrhythmia that can be deadly. It occurs when the heart beats with rapid, erratic electrical impulses. This causes pumping chambers in your heart (the ventricles) to quiver uselessly instead of pumping blood. Without an effective heartbeat, blood pressure plummets, cutting off blood supply to your vital organs.
In the ABO system, (and Rhesus D system) all blood belongs to one of four major groups: A+/â, B+/â, AB+/â, or O+/â. The presence (+) or absence (â) of the RhD (Rhesus D) antigen is indicated by the plus or minus following the ABO type. But there are more than two hundred minor blood groups that can complicate blood transfusions. These are known as rare blood types.
Blood Types. There are four main blood types: A, B, AB and O. Approximately 82 percent of the population is Rh positive, while 18 percent is Rh negative. Type O+ blood is the most common, and most frequently used, blood type. Type O- is the universal blood donor, because most people can accept this type of blood regardless of their blood type.