 Alternating current caused burns in skeletal and heart muscle also inducing atrial as well as ventricular fibrillation in a large majority of the animal experiments.During a year of intense experimentation, in 1961 Lown and coworkers proved that a specific direct current (DC) waveform consistently reversed ventricular fibrillation, restoring a normal heart beat without injuring heart or skeletal muscle.This became widely known as the "Lown waveform."