Serial Electrocardiograms Show Acute Onset of Inverted P Waves in a 62-Year-Old-Male with Chest Pain

Iatrogenic events are common causes of EMS encounters. This report present the case of a 62-year-old male who presented with new-onset chest pain after his primary care provider increased his diltiazem dose to better control atrial fibrillation. The patient presented with nausea, vomiting, diaphoresis, and 8/10 sub-sternal chest pain. Sequential ECGs captured the initiation of a junctional rhythm indicated by negative (inverted) P waves and a shortened PR interval. The patient had also been prescribed dofetilide (Tikosyn), which can raise diltiazem levels. The case emphasizes the importance of recognizing arrhythmias associated with retrograde A/V conduction and raises awareness of potential iatrogenic events as causes for pre-hospital encounters.