73 yo man with abdominal pain. What do you think?
This is a paced rhythm; did you catch the pacer spikes? Can you see how easy it would be to miss these, especially in a busy ED when you feel rushed (you know, like external triaging)? As pacer tech has become more sophisticated the electrodes at the end of the lead have gotten closer together; the size of the pacer spike is proportional to the distance between the electrodes.
Also note that there is A flutter and complete block. A neat trick for picking up flutter waves is to turn the ECG upside down. Often flutter waves can have a negative deflection and so will be more difficult to detect as we are conditioned to look for upright waves (leads II and II here). [You may wish to do this in private otherwise those around may think you're an idiot.]