Principal Component Analysis of the Longitudinal Carotid Wall Motion in Association with Vascular Stiffness: A Pilot Study.
The longitudinal motion of the carotid wall during a heart cycle has a multiphasic waveform. Recent studies have examined the amplitude of this motion. Instead of amplitude measurements, we focus on making a detailed characterization of the motion waveform. Two-minute carotid ultrasound videos were obtained for 19 healthy volunteers, and a speckle tracking algorithm was used to measure the motion of the carotid wall. Principal component analysis revealed the characteristic features of wall motion and their relation to known arterial stiffness indices. By estimating two principal components, we could account for more than 92% of the variation in the motion graphs. The first principal component derived from the longitudinal motion curves was significantly correlated to pulse pressure, indicating that the main dominant base waveform of the longitudinal motion was related to blood pressure. The second principal component derived from the longitudinal motion curves had multiple significant correlations to known stiffness indices, indicating that the stronger biphasic structure of the motion curve, especially on the adventitia layer, was associated with higher distensibility and compliance, as well as reduced carotid artery stiffness. According to this study, the second principal component of the longitudinal motion may be a useful parameter reflecting vascular health.
Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; Department of Clinical Physiology and Nuclear Medicine, Kanta-Häme Central Hospital, Hämeenlinna, Finland. Electronic address: heikki.yli-ollila@khshp.fi.
Heikki
H
Yli-Ollila
Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
Mika P
MP
Tarvainen
Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, Finland; Department of Clinical Physiology and Nuclear Medicine, University of Eastern Finland, Kuopio, Finland.
Tomi P
TP
Laitinen
Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, Finland.
Tiina M
TM
Laitinen
D000328:Adult; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D025341:Principal Component Analysis; D012016:Reference Values; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods* / Q000706:statistics & numerical data*; D059289:Vascular Stiffness / Q000502:physiology*; D055815:Young Adult
Arterial stiffness; Carotid artery; Eigenvalue; Eigenvector; Ultrasound imaging