Focused Review on Transthoracic Echocardiographic Assessment of Patients with Continuous Axial Left Ventricular Assist Devices

Figure 1

Aortic regurgitation after implantation. Patient presented with new onset heart failure 6 months after LVAD implantation. LVAD evaluation showed increased power and LVAD flow. (a) Pre-LVAD parasternal long axis view showing mild diastolic aortic regurgitation. (b), (c), and (d) Immediately after LVAD, blood is pumped from the LV into the aorta creating subphysiological LV pressures. The retrograde aorta to LV gradient increases and continues throughout the cardiac cycle, including most of the systolic phase. Aortic regurgitation has increased in volume and takes place during most of the cardiac cycle. (e) and (f) Six months after LVAD surgery. Aortic regurgitation deteriorated secondary to closed aortic valve encountering high retrograde pressure gradient throughout the cardiac cycle. The progressing regurgitant volume increased left ventricular diameter, which in turn amplified LVAD preload and output. Pump output spiraled up to very high levels, while actual systemic blood flow fell. The end result was a “futile cycle” consisting of high pump flow, low total cardiac output, and high left ventricular and left atrial pressures.