Tried to do a 12 lead on a pt. using an E series Zoll. Applied all the electrodes and wires, pushed the acquire button and got the message V-1 not connected. Pushed on the electrode nothing. Replaced electrodes nothing. Changed wires nothing. Happened to have another monitor on scene, switched to that one still no V-1. Luckily it was not a cardiac event and I signed the pt.. The rest of the calls I ran that day 12 lead worked fine. Is it possible it was the pt. and not the monitor?