Acute Pulmonary Edema After Overdrive for Atrial Flutter

Report of a Case. A 57-year-old black man with a history of hypertension, congestive heart failure, mitral regurgitation, and atrial flutter for the past 2 weeks was admitted for progressive shortness of breath, dyspnea on exertion, and palpitations for the past 3 days. He was found to have congestive heart failure and atrial flutter with variable atrioventricular block and rapid ventricular response. At the time, he was being treated with digitalis, angiotensin-converting enzyme inhibitors, diuretics, badrenergic blocking agents, calcium-channel blocking agents, and anticoagulation therapy. The results of a physical examination were remarkable for the following: blood pressure, 85/50 mm Hg; heart rate, 150/min; respiratory rate, 24 breaths/min. The patient was awell-developed,obesemaninmildrespiratorydistress.There was 4-cm jugular venous distention. Crepitations were audible over the lower third of both lung fields, with a grade III/VI systolic murmur on the apex that radiated to the axilla. The liver was palpable 1 cm below the right costal margin (span, 12 cm). Pedal edema was present (1+). The patient underwent overdrive pacing to sinus rhythm. Within 10 minutes of pacing, a marked increase in shortness of breath, severe distress with accessory muscle use, and rales and crepitations over the entire lung fields were noted. Noninvasive positive pressure ventilation with bilevel positive airway pressure, supplemental oxygen, nitrates, diuretics, and bronchodilators were given with gradual improvement and clinical stabilization. Ancillary laboratory data, including cardiac enzyme levels, were unremarkable except for hypoxemia and respiratory alkalosis in the results of arterial blood gas testing, sinus tachycardia on an electrocardiogram, left atrial enlargement, and left ventricular hypertrophy; the results of a chest x-ray examination showed cardiomegaly and diffuse bilateral alveolointerstitial infiltrates. Echocardiography (transthoracic and transesophageal) showed diffusely hypokinetic left ventricle with an ejection fraction of 40%, a dilated left atrium without clot in the appendage, and severe mitral re