Chapter 11 - Diuretics and Neurohormonal Medications

Abstract

Excluding catastrophic hemodynamic instability, medications are the first-line therapy for secondary mitral regurgitation and at least temporizing therapy for primary or acute mitral regurgitation and mitral stenosis. In mitral stenosis, there is an increase in the left atrial pressure which in turn increases the pulmonary artery pressure, similar to mitral regurgitation, but different in that there is decreased left ventricular filling. Therefore, there is no role for afterload reduction in mitral stenosis. Instead, management focuses on the treatment and reduction of left atrial and pulmonary artery pressure. In mitral regurgitation, there is also increased left atrial and pulmonary artery pressure, but additionally, there is increased left ventricular pressure and therefore the benefit of decreasing afterload. In acute mitral regurgitation, there is an abrupt increase in left atrial pressure causing patients to acutely decompensate as opposed to chronic mitral regurgitation as patients can compensate better although often eventually become symptomatic. Treatment is similar, but in the acute scenario patients benefit more from intravenous nitrates. It is imperative to treat underlying conditions as well such as hypertension and left ventricular dysfunction, especially in the setting of chronic secondary mitral regurgitation. In this case, the treatment is focused on the underlying cause of the disease, typically left ventricular systolic dysfunction. Overall, the medications for the treatment of mitral valve dysfunction are useful in stabilizing patients and managing their symptoms.