This 84-year-old man called 911 because he felt dizzy and fell.  He was not injured in the fall, but the paramedics noted a slow pulse. He denied significant medical history. The initial ECG showed sinus rhythm at about 80 bpm and AV dissociation with an apparent acellerated idioventricular rhythm at about 40 bpm.  Less than one minute later, he has developed a complete heart block with an idioventricular escape rhythm less than 30 bpm.  The escape rhythm speeds slightly toward the end of the strip.  He retained stable vital signs and adequate perfusion during transport.  It is presumed that he was scheduled for an implanted pacemaker.  It is interesting to note the machine's interpretation, and it reminds us to always interpret the ECG ourselves.   Thanks to ECG Guru member, Sebmedic, for his contribution of this ECG.