Cardiac dysfunction is a common accompaniment to severe sepsis. Clinical management of the same complicating pregnancy presents unique challenges balancing maternal and fetal well-being. Can short-term intravenous (IV) tri-iodothyronine (T3) be used in the management of these patients? T3 has been reported in varied clinical settings to favorably affect cardiac lusitropy, inotropy, and chronotropy without significant side effects.We report a case of acute severe left ventricular dysfunction in a pregnant woman with severe acute respiratory distress syndrome on veno-venous extracorporeal membrane oxygenation managed with short-term IV T3. Hemodynamic stability was rapidly achieved and the improvement in contractility imaged in real time by transesophageal echocardiography.<. Learning objective: Tri-iodothyronine (T3) rapidly affects cardiac inotropy, lusitropy, chronotropy, and systemic vascular resistance. Widespread application of intravenous T3 for treatment of heart failure is currently limited by a paucity of scientific literature. Selective short-term intravenous T3 use is an underutilized adjunct in the management of acute left ventricular dysfunction.>.