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.
A VOLTAGE REGULATOR regulates the charging voltage that the alternator produces, keeping it between 13.5 and 14.5 volts to protect the electrical components throughout the vehicle. There is also a system to warn the driver if something is not right with the charging system.
If it is, the voltage regulator may be out. It may be a stand alone part or an internal part of the alternator. Most shops can check this for you with a simple two wire hook up at the battery. Save yourself some time and trouble and get it checked by a shop.