This is one of the most scary arrhythmias, called ventricular fibrillation. Death would be unavoidable, unless the arrhythmia ceased spontaneously in a few minutes. To save a patient with ventricular fibrillation, cardiac resuscitation, followed by electrical defibrillation, is required as soon as possible.
Given that it takes dozens of seconds to record a standard 12-lead ECG, the present ECG is no doubt extremely uncommon. I would say that you have never seen an ECG like this, even though you are an experienced cardiologist. Actually, this is my first time during about 20 years of clinical experience as a cardiologist.
I quote this ECG from my website, where more than 300 ECGs with a simple explanation are available free of charge. While I was uploading an ECG of ventricular fibrillation, my little child, kindergartener at that time, mumbled anxiously, "Oh my goodness...he's dead." Of course, he has never learned about ECG.
Ventricular fibrillation seems to be so striking that even kids cannot help feeling something ominous.