Flow Patterns in the Carotid Arteries of Patients with Left Ventricular Assist Devices.

Background: The aim of this study is to evaluate and define the expected flow pattern changes of carotid artery duplex ultrasound after left ventricular assist device (LVAD) placement.

Methods: Retrospective review of Henry Ford Hospital database of patients who had undergone LVAD placement between March 2008 and July 2012 was performed. All patients who had carotid artery duplex scanning before and after LVAD placement within 2 years of each other and showed <50% stenosis were included in this study. Type of waveform, carotid peak systolic velocity, and end-diastolic velocities were analyzed, and the values were compared before and after LVAD placement.

Results: A total of 13 patients with LVAD had at least 2 carotid duplex studies before and after LVAD placement within 2 years of each other. Of those, 92% (n = 12) were men, and 61% (n = 8) were Caucasian. Mean age was 61 years old. The HeartWare ventricular assist device was implanted in 4 patients and the HeartMate II left ventricular assist device was implanted in 9 patients. Post-LVAD Doppler imaging demonstrated parvus tardus waveform. Analysis of flow velocities revealed that peak systolic velocity was diminished after LVAD placement in both the internal and common carotid arteries (P = 0.006 and P < 0.0001, respectively). End-diastolic velocity, however, increased post-LVAD (P < 0.0001). Interestingly, mean flow velocities in both the common and internal carotid arteries remained stable after LVAD placement.

Conclusions: This study reveals changes in waveform morphology and peak systolic and diastolic velocities in the common and internal carotid arteries on carotid duplex after LVAD placement. Additionally, it shows that despite changes in post-LVAD pulse pressure in the carotid arteries, the mean flow velocity remained unchanged.