Scenario: The rhythm strip below was printed from the bedside monitor of a 71-year-old man admitted to the intensive care unit for hypoxemic respiratory failure, fluid overload, and septic shock. The patient’s history includes coronary artery disease, hypertension, diabetes, paroxysmal atrial fibrillation after successful cardioversion (prescribed at-home apixaban), alcoholic cirrhosis, heart failure (ejection fraction, 50%), and chronic obstructive pulmonary disease (COPD). When this electrocardiogram (ECG) was generated, his blood pressure was 119/63 mm Hg, heart rate was 95/min, and oxygen saturation was 97% while receiving mechanical ventilation with a fraction of inspired oxygen of 0.8. The nurse noted that the rhythm looked like either a heart block or multifocal atrial tachycardia (MAT) and decided to record a 12-lead ECG (see next page). What is your interpretation?
Atrial flutter (AFL) with 3:1 conduction with a ventricular rate of ~100/min and right bundle branch block (RBBB).
Atrial flutter is common in...