A 23-year-old female and first-year medical student presents to the emergency room with altered mental status. Her friends say she has been drinking hard liquor non-stop for 1 week after her final exams and has not been eating well for months. She was recently started on erythromycin for an upper respiratory tract infection.
Her temperature is 37.0, blood pressure is 90/50 mm Hg, heart rate is 70 beats per minute and respiratory rate is 10 per minute. She appears thin and cachectic. She is arousable but unable to answer questions or follow commands. Her heart and lung exam are normal.
Her laboratory studies reveal a potassium level of 2.1 mmol/L (normal: 3.5 mmol/L to 5.0 mmol/L), a magnesium level of 0.9 mEq/L (normal: 1.8 mEq/L to 3.0 mEq/L), and a calcium level of 5.0 mg/dL (normal: 9.0 mg/dL to 10.5 mg/dL). Her ECG is below.
What are the ECG findings?