Focused Review on Transthoracic Echocardiographic Assessment of Patients with Continuous Axial Left Ventricular Assist Devices
Figure 5
LVAD speed settings. Columns: (a) minimal speed; (b) submaximal speed; (c) maximal speed. Rows: (1) pulsed Doppler, outflow cannula; (2) M mode aortic valve. The status of aortic valve opening and aortic flow pulsatility depends on pump speed and output, LV contractility, preload, and afterload conditions. Reduction in LVAD speed to minimum will result in minimal unloading of the LV, increased LV systolic pressure above aortic pressure allowing pulsatile flow (a1), aortic valve opening during every cycle, seen in M mode (a2). Increasing the speed to submaximal, will unload the ventricle, reduce systolic left ventricular pressure, decrease the outflow pulsatility (b1), and result in intermittent aortic valve opening in M mode (b2). Increasing speed to maximum will unload the left ventricle even further, resulting in almost continuous aortic flow (c1), and no aortic valve opening (c2).
