Slope of the Anterior Mitral Valve Leaflet: A New Measurement of Left Ventricular Unloading for Left Ventricular Assist Devices and Systolic Dysfunction

Abstract

Left ventricular assist device (LVAD)-T herapy with an implanted continuous-flow left ventricular assist device (CF-LVAD) has improved survival rates and quality of life in patients with endstage heart failure by increasing cardiac output and decreasing left ventricular (LV) preload.1-3 In non-LVAD-supported patients with heart failure, multiple transthoracic echocardiographic (TTE) methods exist for evaluating LV filling pressures, including chamber dimensions, mitral valve inflow Doppler measurements, pulmonary venous Doppler measurements, and tissue Doppler velocities. [4][5][6] In patients with nonphysiologic unloading of the LV by a CF-LVAD, acquisition and interpretation of the Doppler and echocardiographic images required for many of these accepted methods might be challenging. Even in circumstances in which accurate Doppler evaluation is possible, some studies in CF-LVAD patients have revealed that, although E/e′ ratio decreases after LVAD implantation, it correlates poorly with invasive measurements of pulmonary capillary wedge pressure (PCWP). 7,8 Other guidelines are therefore needed to supplement current knowledge toward evaluating LV unloading and clinical status in CF-LVAD-supported patients.The mitral valve is a fast-moving structure, the motion of which is best detected with the superior temporal resolution of M-mode echocardiography in the parasternal views. 9 In the presence of elevated filling pressures, the anterior mitral leaflet tracing in M-mode displays gradual closure after the peak of the A-wave in cardiac diastole, as compared with brisk closure in patients with normal filling pressures. 9 In extreme cases, this closure process slows to the point where there is a recognizable "B-bump" after atrial contraction, which for more than 40 years has been known to correlate with significantly elevated LV end-diastolic pressure (LVEDP)-greater than 20 mmHg. 10Until now, the slope of the anterior mitral leaflet (SLAM) in end-diastole has never

A Pilot Study Evaluating LV Diastolic Function with M-Mode Measurement of Mitral Valve Movement in the Parasternal Long Axis View

“…Therefore, the amount of blood flow entering the ventricle changes according to the diastolic function of the LV, and MV movement is affected accordingly. Some studies have evaluated diastolic function by observing the movement of the MV using the M-mode in the PSLA view [20][21][22][23][24]; however, no studies have conducted a quantitative evaluation comparing it to the Doppler blood flow rate in the A4C view.…”