Left ventricular assist device (Doppler ultrasound)

Last revised by Henry Knipe on 2 Jun 2020

In patients with a left ventricular assist device (LVAD), spectral Doppler waveforms are altered due to continuous flow provided by the pump in the device:

  • waveforms are monophasic with a constant antegrade flow and no flow below the baseline
  • the waveform is typically parvus-tardus with a slow systolic upstroke and rounded systolic peak
    • less commonly there may be non-pulsatile flow with no systolic peak
    • the systolic peak is thought to be due to intrinsic residual myocardial reserve pumping some of the blood, whereas lack of a systolic peak is thought to occur when the left ventricle is simply acting as a passive conduit and all blood is being pumped by the device
  • peak systolic velocity (PSV) is reduced

These findings have been demonstrated diffusely in multiple arterial beds, including the carotid, vertebral, subclavian and common femoral arteries.

Radiographic features


Spectral Doppler-derived indices of intracardiac hemodynamics, measured as part of repeated comprehensive echocardiographic studies, are used to serially assess cardiac structure and function. Echocardiography is typically performed in the following settings 3:

  • pre-operative assessment
  • perioperative monitoring
    • conducted using a transesophageal approach 
    • allows continuous assessment of the positioning and angulation of the cannulae during introduction 4
      • subsequent (spectral and color flow) Doppler assessment of the flow egress through the inflow cannula should reveal a laminar flow pattern, with a maximum velocity <2 m/s 
      • the patency of the outflow cannula should also be sought
    • color flow Doppler is also used to screen for the presence of the following, which may portend a complicated clinical course: 
  • post-surgical evaluation
  • routine surveillance

ADVERTISEMENT: Supporters see fewer/no ads