I have to have ECGs every 6 months for my aviation medical, h. They always show this strange anomaly, where occasionally a blip which should go up actually goes down. They always frown and shake their heads and then mutter about it probably not mattering.
Oh the occupational ECG's well yes, of course, I have one every two months for my work as a high speed motorcycle stunt man - can't have us popping a biggy and ploughing into the heaving crowd now can we!