Which disorder can initiate atrial flutter?

• A. Hypovolemia
• B. Hyperkalemia
• C. Pulmonary edema
• D. Pulmonary embolism

Answer: (D)

Atrial flutter starts when a reentrant circuit forms in the atria, often driven by acute atrial stretch or irritation that alters conduction and creates a self-sustaining pathway. A pulmonary embolism fits this nicely because the sudden obstruction in the pulmonary vasculature causes acute right heart strain and right atrial dilation. That rapid change in atrial pressure and size sets the stage for a reentrant circuit to emerge, initiating atrial flutter.

The other options don’t typically act as triggers for this arrhythmia. Hypovolemia lowers preload and doesn’t specifically provoke the atrial reentry mechanism. Hyperkalemia disrupts conduction and normally leads to bradyarrhythmias or ventricular issues rather than initiating atrial flutter. Pulmonary edema reflects left-sided pressures and can predispose to atrial fibrillation more than atrial flutter. Therefore, pulmonary embolism is the scenario most associated with initiating atrial flutter.