We were called for a diabetic problem. We fixed him right up but my partner became concerned when his initial heart rate was 38. That could be a problem. We printed out about a mile of EKG strip to figure out that he was in a second degree atrioventricular heart block type 1, aka Mobitz 1, aka a Wenckebach. (my parents love when I throw down the big words) Turned out that this was completely normal for him, but I explained that we didn't see this everyday which might explain our excitement and fascination. In fact when I did a 12 lead I think I said it was only to satisfy my own curiosity, as his was after all, a diabetic problem. He didn't mind and he was happily asymptomatic, as are most of these patients, but it looks cool anyway. Well, to nerds. Unsurprisingly, the LP 12 interpretation was wrong.