Diagnostic and therapeutic considerations in acute, severe mitral regurgitation: experience in 42 consecutive patients entering the intensive care unit with pulmonary edema.

Forty-two consecutive patients received emergency treatment for acute mitral insufficiency causing pulmonary edema between 1984 and 1992. The underlying diagnoses were acute myocardial infarction (n = 21), acute bacterial endocarditis on the native mitral valve (n = 9), prosthetic endocarditis in the mitral position (n = 4), acute failure of a replacement valve (n = 5), blunt chest trauma (n = 1) and chordal rupture in Marfan's syndrome (n = 2). Dysfunction of the subvalvular apparatus was present in 24 patients, verified by transthoracic echocardiography in 18 (75%) and by transoesophageal echocardiography in all patients in whom this technique was used. There were four cases of outflow strut fracture of a Björk-Shiley mitral prosthesis; a reliable diagnosis was made by fluoroscopy in all patients. Bedside hemodynamic monitoring was found to be unreliable both for differential diagnosis and for the quantitative assessment of the degree of mitral insufficiency. The right ventricular filling pressure was normal in 32/39 patients (82%), and the pulmonary artery and pulmonary capillary pressures elevated in 37/39 (95%). Diagnostically important, high pulmonary capillary v-waves were documented in 13 patients (33%). The left ventricular impedance could be influenced with sodium nitroprussid combined in some cases with dobutamin, and the resultant decrease of the peripheral vascular resistance from 1480 +/- 222 to 702 +/- 86 dyn x sec x cm-5 was followed by a proportionate reduction in the transmitral regurgitant fraction. Three patients died prior to the intended emergency surgical intervention. Emergency surgery was completed in 21 patients with an early mortality of 23.8% (n = 5). Ten patients underwent elective surgery within, and another three later than one year from the onset of the acute symptoms with an early mortality of 7.7% (n = 1). Four patients are alive and clinically well with medical treatment alone.