The E/e' Ratio: As "Critical" As the Left Ventricular Ejection Fraction?

Abstract

Ascertainment of the left ventricular ejection fraction is the primary reason for ordering echocardiography in the acute care setting; however, this parameter does not provide information regarding a patient's volume status. As such, it cannot be reliably used to inform decisions regarding intravenous fluid resuscitation or diuresis, particularly in undifferentiated dyspnea and hypotension. This is relevant given a national quality improvement exhortation to provide aggressive fluid resuscitation as part of a "sepsis bundle." This initiative must be tempered by the well-established increase in hospital mortality from providing intravenous fluid to patients with unrecognized heart failure, which may occur if sepsis is misdiagnosed. We describe herein, what is to our knowledge, the first description of a critically elevated Doppler ratio of mitral inflow peak E-wave velocity to the mean mitral annular velocity as a harbinger of sudden death from pulmonary edema in a patient treated with aggressive intravenous fluids as part of the "sepsis bundle." This is utilized as a springboard for proposing a clinical algorithm focused on expedited echocardiography. It emphasized the potential value of advancing markedly the diastolic assessment of filling pressure (ratio of mitral inflow peak E-wave velocity to the mean mitral annular velocity) in the acute care setting to a level of import comparable to the left ventricular ejection fraction.