An Ominous ECG Pattern

A 63-year-old woman with a history of diabetes mellitus and hypertension was brought to the emergency department by emergency medical services for dyspnea on awakening several hours earlier. In the field, the patient had a reported blood pressure of 84/60 mm Hg and oxygen saturation of 85% on room air. On arrival, her pulse rate was 124 beats/min, blood pressure 79/50 mm Hg, respiratory rate 31 breaths/min, oxygen saturation 100% on a nonrebreather mask, and temperature 98.2°F (36.8°C). She appeared to be in moderate respiratory distress despite clear lungs to auscultation bilaterally. A 12-lead ECG was obtained (Figure 1).