Another factor is that cardiac tissue has a chronaxie (response time) of about 3 milliseconds, so electricity at frequencies of higher than about 333 Hz requires more current to cause fibrillation than is required at lower frequencies. The comparison between the dangers of alternating current at typical power transmission frequences (i.e., 50 or 60 Hz), and direct current has been a subject of debate ever since the war of the currents in the 1880s. Animal experiments conducted during this time suggested that alternating current was about twice as dangerous as direct current per unit of current flow (or per unit of applied voltage). It is sometimes suggested that human lethality is most common with alternating current at 100–250 volts; however, death has occurred below this range, with supplies as low as 42 volts. Assuming a steady current flow (as opposed to a shock from a capacitor or from static electricity), shocks above 2,700 volts are often fatal, with those above 11,000 volts being usually fatal, though exceptional cases have been noted. According to a Guinness Book of World Records comic, seventeen-year-old Brian Latasa survived a 230,000 volt shock on the tower of an ultra-high voltage line in Griffith Park, Los Angeles on November 9, 1967. A news report of the event stated that he was "jolted through the air, and landed across the line", and though rescued by firemen, he sustained burns over 40% of his body and was completely paralyzed except for his eyelids.
Otherwise an electrocardiogram, blood work to check the heart, and urine testing for signs of muscle breakdown may be performed.Management may involve resuscitation, pain medications, wound management, and heart monitoring. Electrical injuries affect more than 30,000 people a year in the United States and result in about 1,000 deaths. Signs and symptoms
Burns
Heating due to resistance can cause extensive and deep burns. When applied to the hand, electricity can cause involuntary muscle contraction, producing the "no-let-go" phenomenon, and increasing the risk for serious burns. Voltage levels of 500 to 1000 volts tend to cause internal burns due to the large energy (which is proportional to the duration multiplied by the square of the voltage divided by resistance) available from the source. Damage due to current is through tissue heating and/or electroporation injury. For most cases of high-energy electrical trauma, the Joule heating in the deeper tissues along the extremity will reach damaging temperatures in a few seconds. Ventricular fibrillation
A domestic power supply voltage (110 or 230 V), 50 or 60 Hz alternating current (AC) through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 30 milliamperes (mA). With direct current (DC), 300 to 500 mA is required. If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other kind of electrode), a much lower current of less than 1 mA (AC or DC) can cause fibrillation.