title: Effects of the left ventricular assist device on the compliance and distensibility of the carotid artery.
abstract: We investigated the impact of continuous-flow left ventricular assist devices (LVAD) on the carotid elastic properties. Carotid artery parameters (diameter distensibility (DD), cross-sectional distensibility (CSD), diameter compliance (DC), cross-sectional compliance (CSC), and incremental elastic modulus (IEM)) were measured in a cross-sectional study using a standard ultrasound with a 10-MHz linear array probe. Measurements (mean ± SEM) were made in separate groups at various clinical time points: prior to LVAD surgery (baseline; 13 male/3 female; age 48 ± 3 years), 1 week following LVAD placement (acute; 12 male/2 female; age 47 ± 3 years), approximately 24 weeks following LVAD surgery (chronic; 13 male/2 female; age 52 ± 3 years), and in a group of healthy subjects (controls; 9 male/1 female; age 51 ± 4 years). Distensibility properties were lower (P < 0.05) in the acute (DD 2.3 % ± 0.4 %; CSD 4.7 % ± 0.8 %) and chronic (DD 2.2 % ± 0.4 %; CSD 4.5 ± 0.9 %) compared with the baseline (DD 5.9 % ± 0.7 %; CSD 12.2 % ± 1.5 %) and control (DD 5.8 % ± 0.6 %; CSD 11.9 % ± 1.3 %) groups. Compliance properties were lower (P < 0.05) in the chronic (DC 4.4 ± 0.7 mm/mmHg × 10(-3); CSC 1.2 ± 0.2 mmHg(-1) × 10(-3)) compared with acute (DC 9.0 ± 1.6 mm/mmHg × 10(-3); CSC 2.6 ± 0.4 mmHg(-1) × 10(-3)) and baseline (DC 11.1 ± 1.1 mm/mmHg × 10(-3); CSC 3.3 ± 0.4 mmHg(-1) × 10(-3)) groups. The compliance properties in the control (DC 8.3 ± 0.8 mm/mmHg × 10(-3); CSC 2.4 ± 0.2 mmHg(-1) × 10(-3)) group were not different from any of the patient groups. The IEM was higher (P < 0.05) in the chronic (6908 ± 1269 mmHg) compared with acute (2739 ± 412 mmHg), baseline (1849 ± 177 mmHg), and control (2349 ± 241 mmHg) groups. Chronic continuous-flow LVAD support is associated with lower carotid artery compliance and distensibility, which may place further strain on the left ventricle.
authors.affiliation: School of Kinesiology, University of Minnesota, Minneapolis, USA. danielle.templeton@colorado.edu
authors.forename: Danielle L
authors.initials: DL
authors.lastname: Templeton
authors.forename: Ranjit
authors.initials: R
authors.lastname: John
authors.forename: Patricia
authors.initials: P
authors.lastname: Painter
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Kelly
authors.forename: Donald R
authors.initials: DR
authors.lastname: Dengel
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D059168:Carotid Intima-Media Thickness; D003187:Compliance; D003430:Cross-Sectional Studies; D055119:Elastic Modulus; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices / Q000009:adverse effects; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012307:Risk Factors; D013314:Stress, Mechanical; D013997:Time Factors; D016896:Treatment Outcome; D059289:Vascular Stiffness; D016277:Ventricular Function, Left