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 is reduced.
These findings have been demonstrated diffusely in multiple arterial beds, including the carotid, vertebral, subclavian and common femoral arteries.
- 1. Cervini P, Park SJ, Shah DK, Penev IE, Lewis BD. Carotid Doppler ultrasound findings in patients with left ventricular assist devices, Ultrasound Quarterly 2010 Dec;26(4):255-61.