Slow regular rhythm in a disoriented patient.

A 65-year-old woman with a history of high blood pressure, diabetes mellitus, hyperlipidemia, chronic kidney disease, and stroke went to a walk-in clinic complaining of intermittent neck, left shoulder, and arm pain for several days. After being diagnosed with pneumonia and started on antibiotics, the patient went home. Th e pain became worse and constant 2 days later, and several hours thereafter her family found her disoriented and diaphoretic. An electrocardiogram on hospital admission showed atrial fi brillation, complete atrioventricular block, and a regular junctional escape rhythm at a rate of 37 beats/min (Figure). QRS, ST, and T changes indicated acute inferoposterolateral myocardial infarction, and the QT interval was long (604 msec; QTc 562). A survey of 11 studies of the culprit lesion sites in acute inferior myocardial infarction found right coronary artery to left circumfl ex coronary artery ratios that ranged from 2.2:1 to 7.0:1 with a mean of 4:1 (1). Furthermore, the artery to From the Louisiana State University Health Sciences Center, the Tulane University Medical Center, and the Interim Louisiana State University Hospital, New Orleans.