Grade I diastolic dysfunction and elevated left ventricular end-diastolic pressure: Mitral Doppler inflow, pulmonary vein atrial reversal, and the M-mode mitral B-bump.

Grade I diastolic dysfunction (DD) is generally associated with a normal mean left atrial pressure (LAP) and normal left ventricular end-diastolic pressure (LVEDP). The first hemodynamic alteration seen in DD, however, is the development of an elevated LVEDP with a persistent normal LAP. This is manifested by echocardiography as a continued mitral pulsed wave (PW) E/A <0.8 (Grade I DD), but with evidence of an elevated LVEDP. Such findings include alterations in PV flow, mitral PW inflow response to Valsalva maneuver, and also the presence of a B-bump on the mitral M-mode tracing. When assessing diastolic function, it may be clinically helpful to assess for this early hemodynamic manifestation of DD.