A 62-year-old man presented to the emergency department with shortness of breath and chest tightness. His initial ECG appeared to have an ectopic P-wave with a lengthening PR interval consistent with second degree AV block - Mobitz Type I. But closer inspection showed a faster, independent atrial rate. The patient was diagnosed with ectopic atrial bradycardia with complete AV block and junctional escape, and was ultimately referred for pacemaker.
Keywords: AV block; Cardiology; arrhythmia; electrocardiology.